I'm not able to get the 4th speed setting to work for the Heat/AC. The first 3 speeds are fine,but when I switch it to the highest setting it goes dead.
I have replaced the A/C relay part# 171959141A with several newer ones and also the actual Resistor part# 321905051 which as far as I know is no longer available anywhere. Except through used/salvage. Upon checking the wires at the 4 speed switch itself. There was power to all wires/connectors except the "Grey wire" which I presume has something to do with the 4th speed not working?!? A wiring diagram would be a big help...Also at the Resistor there is not any power to what I believe to be the 4th speed connection. Lastly, we also changed out the part#307937697. A diode/thermistor? that sets next to the Resistor and is connected via a single black wire and white plastic harness/connector. The single black wire goes into and out of the white plastic connector that connects to the Resistor's first of four connections to the Resistor. The other three wires (L-R) are white,black/green,black/yellow. Hope this isn't too confusing?!?
Could you send me a copy of the electrical wiring involved with this problem? The wiring involved with the 4 speed fan switch/interior blower motor/resistor...Your my last hope!
I have consulted with several VW friends and Fox owners. I had to go to salvage yards and various websites trying to find parts and information. I have spent hours troubleshooting this. I need a wiring diagram or layout of the 1989 VW Fox electrical system especially all that's related to the Heater and AC speed fan.
Any diagrams or pictures "anything" that might help resolve this would be deeply appreciated.
I'm not in a financial position to purchase manuals and especially parts that may be just a shot in the dark approach.
It sounds like you have already spent a fair amount of time trying to solve this problem. You really should just get the service manual and then you'll have all the wiring diagrams right in front of you. The manual has a good description of testing the fresh air blower on page 12.25 and 18 different diagrams for the 1989 model Fox. And it's only $40.
Hi Dude, I think I have the solution for your issue, maybe too late, but... I read it just today...
Here in Brazil we have just too much of these cars, also yours probably has been made here.
The hi speed blower has an auxiliar relay right to the fuse box, to prevent damage on the speed selector button due to the high power current of the 4th speed. Just look to its user manual, sorry that is in portuguese, but very rich in details (you can use google translator, would be "understandable"): http://oficinavw.blogspot.com.br/2012/07/manual-gol-gti.html