Thanks very much. I already have that wiring diagram. Further troubleshooting has confirmed the motor, resistor block and high speed relay plus the fan switch are all in perfect working order.
I found that the voltage at the input to the blower switch reads low. Around only 5 volts! I tracked down the fuse (top left on on diagram) and found the voltage was low right at the
supply side of the fuse. I bridged across from the adjacent fuse (from another supply lead) to the blower motor circuit and all works perfectly!
If you pull the blower motor fuse, you may read the full battery voltage at the supply side but as soon as you install the fuse and turn the fan switch on, the voltage drops to a very low level or practically zero.
There are two small gauge pink wires supplying this fuse. I haven't tried to track them back since they are so buried in a cable bundle behind the dash. Would you know or have a diagram of where they come from?
Apparently there is a break/corrosion or high resistance buildup in the feed wire or a partial short to ground. Also wondering if this path would lead back to the ignition switch and if the problem could originate in the switch. Burned or oxidized connections.
Seems like only about a 18-22 gauge wire is used and same with the brown wire from the fuse to the motor switch. Doesn't appear to be very heavy for a rather high current draw from a motor.
Anyway if I knew where this questionable pair of pink wires goes. Physically. So as to know what to check next would help. Right now I am not sure how this pair of wires ties into the battery positive side.
Wednesday, October 29th, 2008 AT 10:18 PM