What's this relay - 1983 GTV6

Started by Al Campbell, March 01, 2012, 01:24:09 PM

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Al Campbell

Under the bonnet of 1983 GTV6 between the Clutch master and the earth terminal box there's a relay which doesn't appear on the wiring diagrams. Some of the wires look original as they disappear under the original wiring loom wrapping. The black earth wire looks un-original though.

It's fed with orange, red and black wires. I can't find any relays in the manual wiring diagrams fed with those colours.

I can't follow the wires to see what it feeds as the go into the loom.

Any ideas?

AL.



shane wescott

I would try disconnecting and see what doesn't work - just my way of troubleshooting.

it may be a headlights relay someone has put in or another relay to get around a dodgy ignition switch. could even be a rebuild for a dead fuel pump relay.

there are a number of areas where voltage loss can be improved by adding a relay so could be almost anything.

Catch ya

Shane
Current Cars:

No Alfa's :-(

Previous Cars:
1991 White 164
86 White GTV6 Zender Body Kit
90 Red 75 TS
98 Blue GTV 2.0
85 Red 33 1.5 TI
85 Red 33 1.7 Carby
83 Silver 33 1.5 GCL
70 Blue Berlina 1750
70 White Berlina 1750

70 White Berlina 1750 (my first)

Current Bikes:

2002 Yellow Ducati ST2 944

Al Campbell

Shane,

Yep thought of pulling it out, to see what stops, but it's on the round-too list. When I've got the bonnet up I'm usually chasing something more pressing. Weird, relay looks aftermarket but I swear it uses part of the original loom. It's mounted where later models have the altitude compensator, so maybe it's just using wiring that was out in for that, but never implemented on my model.

AL.

VeeSix

Hello Al
I have found that exact same relay on a couple of 90s and 75s and my first thought was yes they do not look original and have been added at some stage, someone should come up with the answer here on the forum  :)
1985 Alfa Romeo GTV6 V6 2.5 12V 
1986 Alfa Romeo 90 V6 2.5 12V
1990 Alfa Romeo 75 V6 3.0 12V Potenziata
1990 Alfa Romeo 164 V6 3.0 12V Zender
1991 Alfa Romeo 164 V6 3.0 12V QV
1992 Alfa Romeo 164 V6 3.0 12V QV

Beatle

#4
Put your finger on it and have someone go through all the switches.  You'll feel it click when energised.  

Is that earth wire actually for the relay?  It may just be an opportune place for an earth wire for another circuit entirely.
 
If the relay seems common to a few different cars, it may be an Australian dealer/distributor add-on, though I can't think what it would be for.  It may be needed for fog lights, hazards etc to pass ADRs.  It may also have been a later add-on due to a factory service bulletin to remedy a fault (overloaded circuit, fire risk etc)

EDIT:  I think Australia may have had unique requirements for the illumination of the handbrake and low brake fluid warning lights back in '83.  Maybe it's to do with that?
Paul B
QLD

Past:
'79 GTV - Loyal 1st love
'76 GT - Track entry
'89 75TS - Saved
'76 Alfetta - Sacrificed
'83 GTV6 - NT bullet
'67 Duetto - Fun
'66 Super - Endearing
'92 164 - Stunning
'85 90 - Odd
'04 GT 3.2 Rosso/Tan - Glorious
'02 156 V6 Auto Rosso/Tan - Useful daily

Cool Jesus

Depending on access and if the relay was installed properly, isn't just a matter of following either the 30 or 87 pin out from the relay to see where it leads you? Excuse the puns!!!
The 30 pin should be the supply voltage and the 87 pin is the supply switch to the item being turned on. People do have install the relays with these pins interchanged, alternatively the 30/87 pin could be looped to the 85/86 pin for the power supply. then its a matter of only following one wire.

Alternative (if its a normally open relay) is to set up a test light on the 85/86 pins to see if it energises off the ignition. If it doesn't its either being triggered off a temperature sender (or other sender) or may not even be connected if there'snly three wires?
Present:
* '76 Alfetta GTAm 2.0 (project)
* '03 147 2.0 TS
*'12 159 Ti 1750 TBi
===================
Past:
* '10 159 2.2 JTS
* '89 164 3.0
* '98 Spider 2.0 TS

Cool Jesus

Present:
* '76 Alfetta GTAm 2.0 (project)
* '03 147 2.0 TS
*'12 159 Ti 1750 TBi
===================
Past:
* '10 159 2.2 JTS
* '89 164 3.0
* '98 Spider 2.0 TS

Al Campbell

VeeSix: Thanks for letting me know you've seen them before. MAkes me feel a little better.

Paul: I must confess I haven't tested to see when or if it operates. If it's for something that has since been removed it's not an issue. If it's for something that is still installed then it's working, but yes I'll test to see if it operates.

That earth wire that uses the relay mounting screw is for the relay it just doesn't look like it from the photo.

Yes the '83 does have different wiring for the hand brake fluid warnings. I have the original Australian delivery diagrams and they don't show the way the car is wired in that area. There is an orange wire off the relay and I can't find an orange wire on any relay in the circuit diagrams. I'll be able to move the float on the brake master and hear if the relay operates or if it's for the hand-brake, pull the relay and the light won't work anymore.

Cool: I tried following the wires but they disappear under the wrapping of the original loom. The only unique colour is orange, and I can't find that in the in the circuit diagrams, which may be 'cause it's an ADR mod and they never updated the drawings.

I have seen that "what's this thing" picture before and the relay isn't shown. It's mounted where No. 37 - "Altitude Compensator" is in the picture (I don't have one of those).

O.K. some things to test.

Thanks guys.
AL.

Cool Jesus

Not wanting to state the obvious here, but is the car playing up? or is this yourself just being Alfa OCD like myself and you just gotta know?
Present:
* '76 Alfetta GTAm 2.0 (project)
* '03 147 2.0 TS
*'12 159 Ti 1750 TBi
===================
Past:
* '10 159 2.2 JTS
* '89 164 3.0
* '98 Spider 2.0 TS

Al Campbell

Alright solved it.

It probably is related to the Brake fluid warning float and the unique ADR cct.

One side of the relay coil (86) has an Orange wire that goes to a single spade terminal connector. The other terminal of that connector has two orange wires in the same crimp of the spade connector, both wires go into the original wiring loom on the engine bulkhead. There is another orange wire on the brake fluid warning float, resistance is 0 ohm between the relay and the float. Guess the other orange wire goes to the warning light.

Other side of the coil (85) has red-black wire that goes to terminal block under cover next to the relay in the photo, plugged into a 4 way spade terminal with nothing plugged into the other 3 terminals. So as is the relay coil is never energized. Maybe it is intended as a test  or servicing point.

This is where it gets more odd. Black earth wire from screw mounting for relay is connected to relay contact (30), then loops across to the other side of the contacts (87). That is the relay contacts are shorted and connected to earth.

Maybe it was intended to be used for a different brand of Brake Master (mine's ATE) and you cut the short across the contact and plug something in to the test point.

By the way both brake fluid and hand brake lights work.

Thanks,
AL.


martym00se72

Thanks for that Sportiva,
I found this relay when I was chasing my recent startup issue and wondered what it was for - I moved on from it when I worked out it wasn't the smoking gun I was looking for. I did wonder what it was for but never followed it up.
Cheers
Marty
'83 GTV6 - 3.0 is in! Ohhh yeah!
'99 156 T-spark - Formula 98 ready!

What do people do with their old 2.5...?