Relays

[imported_brackie]

I've scoured the Bentley and can't find what the following relays operate.




Any ideas? I've been having trouble starting the red diesel on these very cold (-6C) mornings but when I hot wire the glow plugs from the battery she starts OK (for an old girl!)



The car has aircon so the fuse board has been relocated to a vertical position. This relay (unplugged) seems to control wipers and heater fan, however if I waggle it I hear the second top relay clicking and if I remove it she starts heaps better (yet to be tested on a cold morning). There's also a voltmeter in the car and it stops reading when this relay is unplugged.

And yes, the glow plugs are brand new and I've substituted a known-to-be-good glow plug relay.

[peter_j_g]

Hi,

The relays in the top two pictures are for the air-conditioning. From memory one of them is for the compressor clutch and the other is to switch the radiator fan on when the air is on.

The voltmeter is on the same circuit as the heater fan, so removing the top relay will cut the power to the fan.

The air-con was installed when the car was new, it was the system that was sold by VW Australia but I havn't seen any description for it in any manual, Bentley, Haynes et al. There are some similarities to the US market rabbits but that's all. Many years ago I also had a petrol 79 GLS with the same aircon system and wiring setup.

Interesting that wiggleing a relay causes another one to click - are they all seated correctly?

Hope this helps!

Best regards, Peter

[imported_brackie]

Now we're getting somewhere!

OK... If they're aircon relays that would explain the link with the heater fan relay. But it doesn't explain the greater willingness to start when the relay is removed. Could there be a current drain somewhere thus preventing the glow plugs from receiving full volts? I've noticed that the voltmeter seldom climbs above 13V and I would expect to see nearer 14V.

[peter_j_g]

Hi,

The voltmeter takes it's feed from the back of the heater fan switch. It may be that it would register a bit higher if the feed was taken further upstream or direct from the battery or alternator. The voltmeter was in a previous golf of mine, so I moved it wiring and all.

Strange that removing the relay improves starting. Sounds like there is a current drain somewhere... have you verified it with a voltmeter & ammeter at the battery?

Regards, Peter

[imported_brackie]

Better

Not too cold last night..... Only -1C but without the relay in place she started first pop. Must be a volt drop somewhere in the heater/wiper area. Looks like a big detective job to find it though. Anybody suggest some shortcuts to save me time?

[syncro]

Is it the K relay socket or L relay socket?

L is for GTI
K is for accessories.

[imported_brackie]

L

The realy was in the L socket

[syncro]

There should be one in the K socket and none in the L.
Do the pins match the holes or is there a spare small hole?

[imported_brackie]

K socket

You're too quick for me syncro No, it was in the K socket. The light was bad when I removed it (the camera flash lit it up in the pic)

I think what I'll have to do it disconnect the aircon relays until I get time to do a volt drop trace.

[syncro]

Disconnect your heated rear screen to test. (Pull fuse 5)
Try removing fuse 10 (heater fan and maybe dodgy ac)