So, I've got a great older model 1997 A6 2.8 Quattro that runs perfectly - except I've been trying to get to the bottom of an issue with my fans not coming on.

I'm at my wits end with reading/searching forums to no avail - you fine folks are my last hope.

Let me preface this post with: I'm not too handy with electrical issues, the "lingo" is a bit confusing to me. So, even if you type reeeeal slooow, I still may not understand you.

So, I found the dual stage - 2 temp switch at the bottom of the radiator and replaced it.

Prior to that, I found a fuse box/panel in the driver's side floor to the left of the hood lever. I checked the large 50 and 60 amp red and blue fuses, I checked the small 30 amp and 5 amp also located there - everything appears fine.

I purchased what AudihausAZ claims is the appropriate fan relay...its a 70A which I have had a hell of a time trying to determine where it goes. (It seems every forum/blog posts images and schematics of other model cars which only confuses matters for my tiny brain).

I eventually looked under the hood on the driver's side at the fuse box - I found no relay that resembled the relay I received with two smaller and two larger prongs on it.

After removing the cover under the steering wheel I found a bar of relays and unplugged a few until I found one that had the same prong configuration. It was the one farthest to the left (closest to the driver's side door) that appeared to be the same....so, I replace it.

Still....no fan action.

I let it idle until it overheats and spews antifreeze after each "test"...I'm getting frustrated. I've checked every fuse in the fuse panel in the dash between the door and the dash on the driver's side....al of them under the hood too....

When I turn on the Air conditioning, the fan runs - makes no sounds, blows COLD air.....but, still, neither fans run under the hood.

When I spin both fans by hand, they turn relatively easily....not really any "resistence", no squeels or sounds. I will say they don't spin as freely as I might guess they could? I mean, if I "flip" either one with my finger, they only spin like a 1/4 rotation or more.

I don't own a test light, but if I did....I'm not sure what the f@#% I'd do with it.

I'm hoping I'm donig the right things here, but I'm not even sure I replaced the right relay....maybe my brand new coolant switch was bad from the autoparts company?

Ugh.

Please help! Any and every suggestion is GREATLY APPRECIATED!

 

One other thing, I drove the car down to my local Advance Auto store so they could check the "check engine" light code for me and the OBDII device they have has the same number of pins, I even looked to confirm that they are the same number of pins and the 4 pins in the middle appear to be a bit flatter in shape than the six round ones to either side - however, the plastic plug part around the pins on their device doesnt fit down into the slot/hole provided in my car!

My local Audi dealers won't touch something this old and the car has been wonderful to me for the past 13 years, we've been up Pikes Peak Twice, across Beartooth Pass, through the Tail of The Dragon....from Northwest Territories of BC to Miami Florida....

I know I'm challenged when it comes to electricity (primarily because I had a bad experience when I was a kid with being shocked) but I've changed the ignition in it, the timing belt a couple times, replaced the alternator once, the thermostat, the water pump a couple times when I changed the belts.......what else, the transmission fluid and filter twice...other stuff, primarily just little maintainance things like switching fuses and light bulbs in the dash...stuff like that.

I could really use a little "heads up" on what to check or how to check maybe the fans themselves?

Thanks again.

 

Ah, well.... I've finally found the wiring/relay info I needed for the C4 here:

justboring: Audi C4 100/A6 Fuse/Relay locations and information

This takes much of the guess work out of it all.

 

So, I've snapped the test light onto the negative battery cable jabbed the test light into the negative post and the thing lights up.

With the key turned to accessory, it lights up a little brighter.

I pulled every fuse one by one from the box in the dash board drivers side by door to see if I could get the test light to got out.

Nothing worked so I proceeded to do the same thing for all the few fuses and relays under the hood at the driver's side firewall.

Nothing worked so I did the same thing with the two large fuses and small fuse and relay under/beside the bonnet/hood release lever.

Nothing worked so I pulled each relay from the bar of relays under the steering wheel.

Nothing seems to work.

I pulled both fans and as I suspected, when I connected them directly to the battery they both spin fast and furiously making no noise.

I hooked the battery back up, turned the ignition to get the A/C fan going and then grounded my test light and started checkeing the wires to my fans I'd just cut out - of course, there's no power getting to either fan.

I'm not sure where to go from here really.

Bloody Hell.

I've read where I can get the codes from umping the right hand connections of the two connectors up front of the fuse box by the driver's side firewall. Well, of course, I don't have either of those connections in that box.

I'm beginning to think this year model is an odd-duck, unlike the others. I'm pretty sure it was a first-half the year 1997 (as I'm seen where the later half have different steering wheels with radio controls in them).... It just seems as if nothing I discover in these forums applies to this car.

(expletive)

 

So, after switching the Relay/Switch i nthe #2 Position ....now when I turn the A/C on, both fans run.

The more I mess with this thing the less I know.

I'm guessing maybe I have some kind of vapor lock in the coolant system somewhere now since I'd drained it all to replaces the two-step temp switch in the bottom of the radiator????

Is this common, to get an air bubble that keeps the coolant fro flowing throughout the engine?

I've located the bleeder valve but have yet to adjust is since I'm still not sure if/what that'd even do to help my situation.

I'm now wondering if the last thermostat I put in there a month ago was bad?

Am I just writing into the wind? Does anyone even read these boards?

Should I just go find another board to torment? This place seems beat up to me.