mwadems

Howdy! New to forum but have been browsing for a long time. Great site! I have an 84 4ks (non-quattro) That ran fine until one day the Radiator fan quit, as well as the horn and Heater Blower motor. All at once. No blown fuses, ground is good. Swapped out a few relays with no difference. Can an ignition module cause this kind of failure? Thanks in advance!

mwadems

Load reduction Relay? I found similar post on Page 13 of the forum..Anybody? Thanks again..

Tony Hoffman-4000Q

However, check for spark and see if the fuel pump is running. That will give us a better idea of what we are looking for.

Tony

Whitjr

first do you have a bentley manual? wiring diagrams are difficult to dicifer, however can give you ideas about what's on which line.

2nd- Take a look at the wiring behind the instru cluster. Take cover off of the istru cluster [two screws on my '84, removes the cover] see if there's any gross burned wires, look for the brown wires as these are the ground. while you are back there, take a peek at the light switch wiring, as this can be a culprit of many many problems.

3rd- has there been any "improvements" to the interior wiring?

Let us know what you find....

mwadems

The radiator cooling fan doesn't work,(It actually overheated while I was letting it Idle and that when I discovered the problem) Ac fan motor doesn't work and the lights do not work. The horn may be a red hering, as I honestly can't remember the last time I used it. I have a bently manual, Audi Factory wiring diagram manual, audi repair manual type 81 first edition, Audi ignition systems manual and a parts car, going to try swapping the Load reduction relay and see what happens..Starting major restoration in the spring on the ol girl!

Katman

Lights aren't on the load reduction (the 'x') relay itself..

But you may be on the right track..

Lights ARE fed directly from the 'x' contact on the ign switch. That same 'x' contact also controls the 'x' relay that controls the heater, power windows and sunroof.

So if the ign switch load reduction contact was going bad, you may get those symptoms.


I'm not sure one way or other if the 'x' controls the rad fan though. That problem is more likely to be the rad temp sender, or a bad fan relay. Jumper the connector at the temp
sender, and the fan should come on (with ign on)

YukonAudi

Remove the two leads from the thermo-switch on the rad and short them together with the engine running, fan on? If yes, could be thermo-switch, My bet....these fussy things can be bad from the parts depot. If No. meter the leads to find 12V. If no juice, backtrack to fuse panel.
Horn problem is normally a relay issue or a weak ground.
Blower fan- pull switch and meter for 12V. If no- again follow it back to the fuse block.

Good luck.

mwadems

I appriciate the input. Haven't had time to fully investigate yet. You all have given me enough to start with. I'll let you know what I come up with...