jeff spahn

Alan. I tested the relay. It has 81 ohms resistance both ways of 85 to 86 and 86 to 85. I then ran a diode test with my multimeter and I get .045v in both directions. From what I gather you told me, this means the relay is bad.

I also pulled the relay for the fog lights. My 1990 S4 shows on my relay schematic that it calls for a 928.615.117.02 relay and the horn calls for a 141.951.253b relay. Can you verify this is correct? I'll try to swap them at lunch today.
Have to get the condenser out and see if I can get that repaired or need to swap with a used one i just purchased.

Alan

The horn relay should work on a USA car & mosr ROW cars - Japan cars do need special relay but don't normally have DRL - so I assumed your's isn't?

Yes it appears the DRL relay you have either doesn't have a diode in it or or the diode is shorted closed circuit, seems Martins likely is the same from his symptoms.

Alan

jeff spahn

And this is what happens when you headlight motor arm gets a mind of its own!

first you jack up your car and take off the front air dam.



then you remove the condenser




Then you luck out and buy a used on on ebay for $25 from Los Angeles auto parts from some russian dude.

The you take the broken one to the local radiator repair shop and have them fix it and stick it in your attic for the next time you arm on your headlights freaks out.

ROG100

Just to throw a spanner/wrench into the works ---
The headlight relay in Jeff's car is 928 618 107 01. According to PET an my records this relay (87 to 95) is only used on UK cars which have a different set up on the headlights. My UK SE when turning on the sidelights also makes the headlights flip up and has the 928 618 107 01 relay fitted.
According to everything I see the correct relay for the US cars is 928 618 107 04 (87 to 95).

So why are we using/finding the 928 618 107 01 in USA cars????

Both part numbers are stand alone relays and do not supersede in any way.

Alan

Hmmm indeed ! You'd think the UK ones would be low volume and even more expensive/hard to find.

Roger is this the 'dim-dip' mode I have heard of? do the low beams come on at reduced intensity?

I think you need a secondary module for that lighting function that would presumably only be on a UK car.

This would require that the pod go up in position 2 vs position 3 of the HL switch - a fairly simple change - presumably thats the only change to the HL relay.

I'm pretty sure that the DRL relay is the culprint in both of these case of the HL motor wanting to keep running...

Alan

martinss

You are correct Alan - wrong/bad relay in DRL slot in a 1990 - update posted to my thread. Many thanks for your help.

martinss

I intend to make a 'condenser shield' to protect against future freaky behaviour. Maybe Roger would care to order a production runs worth

martinss

Since I have a Japan car, could you please explain Alan?

Alan

Martin,

Japanese cars normally don't come with DRL installed - their fog relay configuration is different than USA (though actually it does use the same type of relay) - it is not disabled during high beam activation like the USA one is (in his respect its like the std ROW configuration). Most other Japan lighting features are more like USA models.

Alan

FredR

By the way- what exactly is a DRL relay? Clearly I have not got that far into the system yet.

Integrated complex relays = many $$$ plus cries of "NLA".

regds

Fred

jeff spahn

I am going to fabricate a condenser shield after the pain in the *** this is to take the condenser out.

• Have to remove belly pan.
• remove both left and right front wheel well liners
• remove chin spoiler
• remove air splitter metal thingy then pull frame plugs to get to bolts
• Get AT cooler out of the way then you can remove the condenser. Then you get to degrease all the AC oil that went everywhere. Also to top it off I have to remove Supercharger snorkels, supercharger oil cooler attached to condenser.

It would be much easier to make a condenser shield and just zip tie it to the condenser coils.

jeff spahn

To throw another wrench in the works, when you fit the 928 618 107 04 relay to the 90 S4 with the DRL relay in place and you turn on your headlights to the first position, the headlights turn on (albeit slightly dimmed) but stay down. Go figure that one. Perhaps that would work as DRL's but would be a bitch to the squirrels you blind.

Alan

Fred - DRL = Daytime Running Lights.

Basically turns the fogs on automatically whenever the fuel pump is running and the starter isn't active - just as long as the headlights aren't on.

Note - just the fog lights, no markers.

As with many of these systems - risks folks thinking they have their lights on normally at dusk when really they don't. I don't think it's such a great system overall for that reason - and so it is not a net help to others/you if you ask me... If it activated fogs and markers I think it would be more beneficial.

Alan

ROG100

DRL works fine on my GTS and my headlight relay is 928 618 107 04.

Alan - yes dim/dip on the UK cars and as far as I know that is why they use the 01 relay.

jeff spahn

It appears the DRL relay is defective and that caused all my problems. Bummer. Lots of work to get all this stuff fixed.

Glad I found the used condenser for $45 shipped!

On the plus side, I get to pressure wash all the parts I took off and they will be squeaky clean!