It started off so well, Friday I fitted relays for the headlights and Saturday and Sunday I replaced the timing belt and checked the valve clearances. While I had the coolant drained I thought it would be a good time to finally fit a heater tap I'd fixed up. The heater tap was cracked 4 years ago when I put the car on the road but had lasted thanks to Araldite, sheet metal strips, tie wire and a hose clamp. So while I fixed the heater tap I temporarily (for 6 months) plugged the hoses off in the engine bay.
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/HeaterTap.jpg)
This was the last thing on the car that needed attention so I was keen to knock it over. So I fitted the heater tap, filled it up with coolant and went to pick up dinner. When I got back I had damp carpet and there was a steady drip from the AC condensate tube that pokes out of the firewall near the steering rack. In all the jiggling fitting the new tap I must have disrupted the core somehow.
Looks like I'll be busy this weekend.....
Any tips? I think it's probably a dash-out job :(
Scott
When an old heater core is disconnected and allowed to dry out, the rubber seal between the plastic tanks and the metal core can shrink, which then leaks when the core is reconnected. Hopefully this is what you have which can stop leaking in around two days.
Unfortunately, plastic becomes brittle over the years and doesn't like to be touched, even if you look at it the wrong way it can leak, therefore you may have fractured it and the heater core must be replaced.
Also, if it seems to be a slight drip, thinking the plastic is not fractured, you can try some magic and buy a stop leak product. Now, I have been told never to do this, BUT, I use 'Silver Seal', which is a grey powder in a paper tube, and less susceptible to blocking your cooling system.
Thanks for the reply Frank. I've found out the heater core is copper and the loops at the end sometimes crack. I'm glad it's not aluminium, much harder to fix. Unfortunately I still have to pull the dash out. Here's a picture of the core I've been sent:
Thanks, Scott
Sorry about that, thought it was an aluminium core with plastic tanks type of heater core.
Thanks for posting the pic.
Scott ,
I have previously had a heater core leak in the GTV6. The removal of the assembly does not require a dash out but you do need to be contorsionist to get it out. I would think this would apply to the 75 as well.
The fix was a visit to the radiator shop with core in hand. They did a pressure test to locate the leak and resoldered it. End of leak.
Thanks guys. MD I'll have another look but I don't think it's do-able without taking out the dash. It was hard enough just changing the heater tap, but I'll check it out.
I'm just glad it's not a aluminium/plastic heater core.
Thanks guys,
Scott
Scott,
The heater box in the GTV6 can come out without removal of the dash. I have done it before but you need some long extensions and uni joints to get at the retaining nuts under the dash. Once those are out, it's easy to pull it out. However, on the 75's, it's easier to get the dash out :)
My heater core also went around the copper u bends. I think the radiator shop ended up putting solder on most of the u bends to prevent other areas springing a leak later.
Good luck. BTW, how did you repair your heater tap?
bteoh, did my picture show up? Basically I cut the metal band that held the end (with the barb and the flange where it bolts onto the core) onto the main body, and then remade that part in brass. It's a few parts silver soldered together. The ring with the tapped holes slides over the main tap body and sits against a step. Here's another:
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/HeaterTap2.jpg)
Scott
Well done Scott.......maybe you should make a batch up and sell them :)
Cheers,
Brian
Scott, I've just come across this thread, after searching for ages for a new or replacement heater valve for our 75, and here's an answer under my nose! And bteoh is right, you should make some to sell - I'd like to be your first customer, unless someone has beaten me... I'll send you some money, and my postal address, if you tell me how much $$ to make it and post it. My email's stafford.riverland@gmail.com.
Another bit of the puzzle that is the 75 heater, is the cable operated flappy do-dah that pretends to control where the air goes - if you've ventured beyond the outside you may know something about it, but I'd better start a new thread on the topic...
Ciao
Graham
Funny this should come up now, I currently have the dash apart. The picture of the core I posted further up is misleading. I thought that the heater core was horizontal in the heater box but in fact it is standing vertical in the front of the box (at the bottom of the picture). The AC evaporator is behind it. One end has the copper loops like I thought but the other has a crimped on plastic tank. I will pressure test it tomorrow and fingers crossed it is not the o-ring between the core and the end tank.
As for the heater tap, I would need a fair bit of persuasion to make anymore. Not out of the quesiton though.
Graham, can I post any photos that would be useful?
Scott
Quote from: scott.venables on June 13, 2011, 11:00:43 PM
As for the heater tap, I would need a fair bit of persuasion to make anymore. Not out of the quesiton though.
What flavour of persuasion do you accept? I'm pretty sure there is more than a little demand... Put me down for at least 2...
Go on Scott you know you want to..... Put me down for one too ;D
So here's what I'm up to. The heater core was leaking from the o-ring between the core and the plastic tank which is basically unfixable. So I went around to see Hugh at Monza and he lent me a 90 heater box so I could pull the core out of it. It looked the same from the outside except the bottom heater hose attaches to a piece of tube that is extended to outside the box. This is far superior to the 75 arrangement where the complete dash and heater box has to come out to replace the hose. Also, the flange for the 90 heater tap is rotated 90 degrees relative to the 75 one but since the tube with the tap flange bolts onto the side of the core we figure I would be able to swap it over.
So I pulled the box apart and the core was more different than expected. There is no plastic end tank, the 90 core is 3 rows wide instead of 2 and the tube to which the heater tap bolts is not bolted to the core at the other end. So to adapt it into the 75 box I had to cut the 75 heater tap flange and tube from my old core, and solder it to the tube on the 90 core. The barb for the bottom hose was changed to 1/2" as opposed to the original 5/8"
The only thing is, due to the extra width the 90 core will not fit in a 75 heater box unless you swap in the 90 AC condenser, or do without the AC like I have.
This picture shows the 75 core on the left, 90 on the right.
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/HeaterCores.jpg)
90 heater core modified to suit 75
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/NewCore.jpg)
So now it's all ready to put back together, I've worked some oil into the fan spindle bearings, replaced the mesh that covers the heater fan resistor pack, and fixed up a previous owners bodgy repair to the resistor pack itself.
Now the fun begins.......
Nice work Scott! 3-core could mean you'll be ever-so-toasty during winter! ;D
Just some questions about the resistor pack. One of the resistors has the two posts joined by a piece of solder through the middle of the resistor. This seems to be a sort of fuse that melts if the resistor gets too hot and thereby stops the fan working. Mine keeps blowing that fuse after about a week. It is worse if I run the fan on the slowest speed. I keep a spare one in the glovebox. The questions are:
1. Does that solder need to be silver solder, which I presume has a higher melting point? I have been using ordinary electrical solder.
2. Could my problem be the mesh you mention being clogged? If so, I guess the whole heater box has to come out to get at it or can I squirt it with something?
3. Is my fan motor perhaps dragging and overloading the resistor?
4. Is what I think is a fuse not in fact solder, but just a piece of wire? It certainly appears to be solder based on the two resistor packs I have.
5. Can you get brushes and bearings to rebuild the motors?
It's all back together! I had it done last night but finished too late for a test drive. Unfortunately I missed todays Early Morning Run looking for a loose fuel pump wire. It was on the back on the fuse box but I'd already partially removed the dash. Yes it is nice and toasty, but I've been without a heater for a while so I can't remember exactly how good it was before.
Oz, I'm not sure I'll be able to answer all your questions but I'll give it a go:
The bar between the 2 posts was missing out of mine but I believe it was wire (maybe ni-chrome to resist rust?) It's not a fuse but a low resistance path for the highest fan speed. The path across the associated blades and through the bar should be 0.5 ohm. I have used soft solder to attach a piece of stainless welding wire across these posts to the correct resistance. This path shouldn't see any current with the fan on the slowest speed, it should run through the light wire coil(about 3 ohms resistance). The intermediate speed uses the heavier coil (about 1.5 ohms)
The resistor board:
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/ResistorBoard.jpg)
Dad mentioned the possible necessity for silver solder after I had finished so I'll have to see how it lasts. I soldered the ends of the other coils onto their posts as well. The mesh I used(aluminium door mesh) was more open than the original so it should stay cool. The holes in the original mesh were closing up because of rust. I wasn't planning on replacing it but it disintegrated when I knocked it. You could try compressed air though the resistor hole if it's only leaves etc. but if it's rusty you might blow it to smithereens.
The mesh
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/HeaterMesh.jpg)
My motor had plain bearings on the spindle which I freed up a little by just working some oil in. They weren't as free as I'd like but the oil might continue to works it's way in. The spindle was tighter than it should have been and no doubt would have been drawing extra current. I think yours would only be better if someone has pulled the dash out in the not so distant past. I'm not sure if you can get brushes to rebuild the motor.
The heater core stands up vertically in the front of the box, and the tubes poke through the vertical slot to the right:
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/HeaterBox.jpg)
Here's a thread you've found on the BB but it may be useful to others:
http://www.alfabb.com/bb/forums/milano-75-1987-1989/170961-heater-fan-resistor-pack-resistance-values.html (http://www.alfabb.com/bb/forums/milano-75-1987-1989/170961-heater-fan-resistor-pack-resistance-values.html)
Scott
Thanks Scott. That is very helpful. The photos are great. I will try wire instead of solder and see if I can check out and clean the mesh if it needs it. The only thing I am wondering is: why does the fan stop working altogether when that wire is broken?
awesome photo. I cheated and used a 2" holewas and replaced the hose clamp on the rubber pipe on the tank in my 75
"worked " ;D :D ;) :)
Thanks Alphie, I had considered cutting an access hole to get to the bottom hose but luckily I found a better solution.
Oz, all current goes through the bridge you keep replacing, and the motor uses 2 and 3 resistors in series to get the intermediate and low speeds respectively.
Here's a sketch of the terminal layout with resistances and a (very)rough sketch of the mesh piece:
(http://i1085.photobucket.com/albums/j432/ScottVenables/Random%20Stuff/HeaterSketch.jpg)
Cheers, Scott
Thanks Scott. I will save the info and diagrams. It makes sense now.
Oz,
a piece of wire is definitely the right answer - not surprised solder melts. You shouldn't need silver solder if you have good metal-to-metal contact between wire and terminals. Copper wire is fine, you don't want nichrome unless you want resistance - which you don't - will just get hot and make the fan run slower. If you get terminals/wire clean and with metal-metal contact the solder is just there to keep it in place. Clean everything - oxide layers don't conduct well (so create heat) and the solder won't bond well (so crack/fail). The 0.5 ohms of that wire link is incidental - 0 ohms is good too (better - less heat).
Thanks Darryl. Copper wire will be easier to find and solder. I will aim for the 0 ohms mark. This is one of the many things I love about the internet. It makes problem solving through collaboration with others easier than ever.
How about using a pulse width modulated motor speed controller? Jaycar have 1 that can sink up to 10 amps (20 amps with dual MOSFET's) and heat sinks http://www.jaycar.com.au/productView.asp?ID=KC5225&keywords=motor+speed&form=KEYWORD
Quote from: Duk on June 22, 2011, 03:56:41 PM
How about using a pulse width modulated motor speed controller? Jaycar have 1 that can sink up to 10 amps (20 amps with dual MOSFET's) and heat sinks http://www.jaycar.com.au/productView.asp?ID=KC5225&keywords=motor+speed&form=KEYWORD
Thanks Duk. That's a useful thing to know about. Is it controlled by a potentiometer or a switch I wonder? I might check one out for future reference next time I am in Jaycar . It might work on a 164 if the original controller burnt out as they sometimes do. I will stick to the original on the 75 though because it is simple and effective and has the right connections. Once I replace that wire it should be OK.
Hi Scott. I fixed my resistor pack with wire, but after a bit of use the fan stopped working and temporarily cut the power to the radio and I could smell plastic burning. Upon inspection tonight I found that the fan is pretty close to being seized solid, so it is obvious that it is drawing heaps of current and melting the insulation on the power wire on the resistor pack. I am going to have to pull the dash and remove the fan assembly and hopefully overhaul it. Can you please describe the procedure for dash and heater fan removal step by step? I believe the dash is held in by five screws. I hope it is not too onerous.
I should probably have taken some notes and photos, but here goes.
1. Remove the centre and radio consoles.
1b Remove the lower steering column cowl, unplug all the connectors on the indicator/wiper units, the ignition switch connector, remove the bottom steering column bolt, remove the top column adjuster. Now the whole column will slide out of the slip joint.
2. Screws securing the dash:
-2 screws under the aluminium vent at the base of the windscreen
-1 screw on the right hand side of the glove box(inside the glove box lid)
-1 screw on the far left side if the dash behind the glove box in a deep recess above the velcro strip
-1 more on the right hand side of the glove box, at the top of the carpeted opening, just below where the black vinyl dash top meets the grey plastic lower dash
The dash will still sit there with all the screws removed
3. The instrument cluster I'm quite sure can stay with the dash. I took it off without realising but if I was doing it again I wouldn't separate them. Leave the fusebox in the dash, it can be wiggled out forwards through the glovebox opening if you need to work on the back of it but for this it can stay with the dash.
4. The vents at the extreme ends of the dash are a pain to deal with. There's 4 main parts:
1.the duct that attaches to the heater box and is screwed to the firewall (this part won't come off with the dash),
2. a 90degreee elbow that sits in the end of the duct,
3. a part that is nearly permanently in the dash, into this is clipped:
4. the vent in the dash, this is what you adjust to direct the airflow
Parts 2 and 3 on mine were glued and clipped together. When I pulled the dash off these parts separated but a few of the clips broke off. The only way I can see you might get around this is to pull part #4 out of the dash first. There are 2 short pins that stick out the sides of this, the vent swivels up and down around these pins. To remove part #4, use a SPAM knife to spread the sides of part #3 enough to release the pins from their holes (one side at a time) and pull #4 out. Now you should be able to see the join between parts 2 and 3, if you can separate them now that would be great, otherwise you can only hope for the best.
5. Disconnect the heater tap cable at the heater tap and thread it back through. With extreme caution, remove the heater hose from the heater tap. Remove the 2 screws on either side of the heater/AC control panel. With these screws removed the panel will flap about. There is a wiring connector on the bottom of the heater box towards the back that needs disconnecting.
I think now the dash can come out. From memory all the wiring for the heater/radio/gauge cluster stays with the dash, and the fuse box too. So now, if you've taken care of all of the above, and if I haven't missed anything, the dash can come out. You'll need a helper for the other side. All that is holding the dash in now is 2 pairs of 'fingers' (one on each side) that clip around two short (~1" long) steel rods that run across the car on either side. The dash will need a good tug to spread these 'fingers' over the rods. Once the dash is off enough, you need to reach in and unplug the wiring connectors that are roughly behind the oil pressure gauge and on the firewall. Now you need to thread the heater/AC control panel over the plastic piece that runs across the dash under the heater box. And now I think the dash can come out.
To get the heater box out, undo the nuts that hold the ducts onto the firewall. The heater box is held in by 2 screws at the front, once these are out lower it slightly and slide outwards and slightly up to disengage 2 plastic tabs that slide into slots on the firewall. I can't reccommend what to do about the AC lines as I removed them but I'm pretty sure you'll have to work on the heater box in the car. There are screws all the way around the horizontal split that need to be undone, also 5 I think spring steel clips along the front, the 2 at either end come off at the top first. There's sort of 2 top halves if that makes sense, the screws and clips hold the upper top half onto the lower top half and the bottom half, if you lift this upper top half up gently, there's a single self tapper right in the middle of the box that holds the lower top half onto the bottom half. You'll need a stubby philips screwdriver to get this one. Now the two top halves will lift off (although they will still be connected to a control cable), and voila! the heater fan is there to be seen.
I think that's about it. Sorry if I've rambled. I'll re-read it tomorrow or the day after with fresh eyes and see how it reads
Cheers, Scott
Edit:
I forgot to add, there is a control box which I think is for the ARC screwed to the top of the glovebox roof. There's 3 vertical self tappers along the top edge to unscrew then you can lever it out. There are quite a few wiring plugs to be disconnected here.
Also, look at how the wiring for the radio is done. I wired mine up without considering removing the dash. I had to cut the rear speaker wires when the dash was half out and figure out which cut ends went together after the dash went back in. If I'd realised sooner I could have put in some crimp on connectors.
Thanks Scott, that's very thorough and clear. I think what I'll do is to practise taking the dash out of my wrecked Potenziata first. I have already removed the instrument cluster and most of the console, but I can still gain some experience with all the rest. I am not sure what the heater fan is going to be like when I get it out of that car because it suffered from an engine fire and enough heat got into the back of the dash to partly melt the vents and the back of the speedo. The fan is very tight like the one in my good Potenziata, but it might be repairable with any luck. If it is I can do it up and swap it straight in or, if not, use it to help track down a new motor, if such a thing exists or work out how to fix mine. I am going to be very busy in the coming weeks because I also have to replace the blower motor in our 164. I have a brand new one coming over from the US for that. The 164 is probably easier to do because it comes out from the engine compartment. My brother and I took his out early in the year, so we have some experience there.
Let me know if you remember any other details.
Hi Oz. I've tacked on a few things that came to me today. A practise removal is a great idea.
Sounds like a nice design where you can take the 164 fan out through the engine bay!
I've read the 75 heater fan is different to the US Milano version in case you look for one in the US. I'm sure you'll be able to free up your spare heater fan. With the fans removed off the shaft you could in turn soak each bearing in kero/petrol, then blow it out and work some oil in. If you've got a spare to work with then you won't be under pressure when the dash is out of your daily driver. The fans are easily removed and replaced from the shaft if the ones in your wreck are melted
Scott
Quote from: scott.venables on July 12, 2011, 10:53:46 PM
Hi Oz. I've tacked on a few things that came to me today. A practise removal is a great idea.
Sounds like a nice design where you can take the 164 fan out through the engine bay!
I've read the 75 heater fan is different to the US Milano version in case you look for one in the US. I'm sure you'll be able to free up your spare heater fan. With the fans removed off the shaft you could in turn soak each bearing in kero/petrol, then blow it out and work some oil in. If you've got a spare to work with then you won't be under pressure when the dash is out of your daily driver. The fans are easily removed and replaced from the shaft if the ones in your wreck are melted
Scott
Thanks again Scott. The 164 fan removal is certainly easier than replacing the stepper motors which do require removal of the dash. You have to take off the wiper motor and loosen the false firewall and air con unit to get the fan out, but you can do it standing up. It takes a fair bit of wrangling and a few swear words to get it out once everything is loose. I wonder if oil will last long term in the bearings. Could something like anti-seize grease be used instead do you think? I would hate to have it fail again later on. Yes I think the Milano heater units are different because the Americans talk about pulling the motor out from the footwell. It is possible that they have the same motor in a different housing but you would need to check the part numbers. They have a lot of trouble with leaves getting into theirs which we don't seem to have.
Just one question: what did you mean by the centre console?
I've read on the AlfaBB that the US Milano has only one fan, where ours has one on each end of the shaft. I'm sure oil will last in the bearings, it shouldn't get that hot/dusty. My car already had a factory looking mesh cover over the fresh air inlet under the bonnet which I guess the US cars didn't get. There were still a couple of leaves in there.
By centre console I mean the handbrake console, with the gearlever boot in it. Sorry, I could have been clearer on that.
I think I can conclude that soft solder is good enough for the resistor pack, mines still going strong after 3 weeks.
One other thing I did while I had the heater box out was replace the re-circ flaps on the sides of the box. When you flick the control from fresh to re-circ, a stepper motor closes off a flap under the fresh air inlet. So with the fan running, the fans now draw cabin air through the flaps on the side of the box. Mine were both broken but I was able to adapt the ones out of the 90 box.
Scott
Thanks for clarifying the console thing. One of the flaps on the side of my heater box is broken too, so I will try and fix that up as you suggest. So it looks like they did use soft solder as a fuse on the resistor pack as I thought. It would protect the system from getting red hot and burning out the wiring. When I was using solder it would simply melt and cut the power due to the overload caused by my nearly seized motor, whereas with the copper wire the power wire got hot enough to melt the insulation on the spade terminal and nearly blew the fuses. It could potentially have caused a fire. I have had enough car fires to last a lifetime and don't want another, so I might go back to using solder. I was quite sure that the resistor pack from my wreck had solder on it, that is why I was using it.
You won't find an auto mfg using solder as a fuse/wire. I am however prepared to believe that the wire that was originally fitted may have been thin enough and have had sufficient resistance to act as a fuse. Maybe even made out of fuse wire :) I would not suggest using solder instead because of the risk it would fail for purely mechanical reasons.
It would be interesting to have a look at the resistor packs from a few cars to see what they had in there. It only takes a minute to pop it out if anyone wants to have a look and let us know. It is in the back of the heater unit above the radio, held in with a little clip which is easy to get off with a small screw driver. I will check my son's 3 litre when it comes back from the mechanic.