03 Jetta 1.8T Wagon cooling fan problem

Hello.

2003 Jetta Wagon 1.8T Automatic

Over the last month the radiator cooling fans have gone out twice. Took it to the dealer (still under warranty) the first time and they said the fuse blew. They replaced the fuse but did not research why the fuse blew.

Also, before the fans went out the first time, they were running extremely loud. They drowned out the engine noise. I get my oil changed at a local shop that works on VW only. The last oil change I had them check out the fan noise. They told me they were on running on "high". A few days later, that's when they stopped working the first time.

When I picked up my car from the dealer the first time, the fans were working but again, were very loud. I was trying to convince myself that they have always been this loud. Well, a week later the fans went out again.

Took it to the dealer again. Explained to them again the loudness of the fans when they were working. Service manager calls me back two hours later because of a wiring harness I added to the car to supply power to my utility trailor. I have a trailer hitch on this Jetta. She said that her mechanic thinks this is causing the problem with the cooling fans blowing fuses/running on high. She said they could unhook the wiring harness from the battery and see if that does the trick. If not, they would have to dig deeper, and if they discovered aftermarket wiring (which she knew was already there), VW would not pay for the repairs even if the aftermarket wiring was not causing the problem. I did not think adding a wiring harness would void my warranty.

Anyway, she called back that afternoon and said the car was ready - no charge. She said the fuse was not blowing and the fans were running normal. I picked up the car late - fans still loud as ever and wiring harness I installed completely missing from car. They actually removed it from the battery and rewired the wires where I tied it in to the rear brake/tail lights.

I will be calling them first thing Monday morning and ask where my wiring harness went and also why the fans are still running loud.

I'm not sure what to do in this situation.

I'm no mechanic, but I don't understand how a wiring harness for a trailer could cause this problem (it was an aftermarket harness made for Jetta). The harness has been on the car for about 8 months. The fan problem is recent.

Any suggestions on how I should approach this?

I can almost guarantee that the fans will go out again real soon. And with no wiring harness on the car, it seems to me that that would rule out that as the cause.

I hate to think that I have voided the electrical warranty, but if I have I will accept that.

Thanks.

VW's are extreemly anal about wiring and if you added more wires to the original harness it changed the resistance of the wires and problably is making the fans run at the incorrect speed. You shouldnt be towing someting w/ a 1.8t anyway, there not meant for towing. THats what a 1.9tdi is for...

For "towing" I have used an extremely lite trailer with a very lite load (camping) - basically a trunk extension. I mainly use the hitch for a bike rack.

As far as the radiator fan problem, the car is back at the dealer and they are going to attempt to find out what is causing the fans to run high and blow fuses. Since the trailer wiring harness has been removed and the problem still exist, all work will be done under warranty.

I will not be putting a trailer wiring harness back on this Jetta, so my "towing" days are over. Anyways...