Hey guys,

Been reading forum for a while, but never posted. Did a search
for this but did not find this particular problem. Have a 91 RS
with 305 TBI and 700R4. I have lost all speeds on the heater/ac blower fan. Checked the fuses, pulled the fan connector and
checked for power at fan with ignition switch on. Nothing.
Pulled the connector to the relay right next to blower fan in
the engine compartment and checked for power there also with
ignition switch on. Also nothing. I looked for the infamous red
wire of death on the firewall last night. Not there. I saw some
fuseable links down near the battery. Is this the right area to
be checking next? Any help would be appreciated.
I hate electrical problems::

 

Check all the connections on teh blower resistor with the fan switch set at any position EXCEPT high. If you get no voltage to ground anywhere, you may have a switch problem, or may have a problem with the 25A HTR-A/C fuse. If the fues is good, you may have to dig into the control head and diagnose the switch.

The fusible link only powers the fan in the HIGH speed position, through the fan relay. All other speeds bypass the relay completely and power the fan through the resistor array.

 

So if the fuseable link was fried, I would still have low and medium speeds on the blower? Since I don't have low, medium or high, I guess I will check the resistor block then the switch since I already checked the fuse earlier. So do I maybe also have a relay
problem since I don't have high speed either?

 

For any blower speed, the power must come through the switch in the control panel. If you cannot read voltage at the resistor or the relay, you need to work backward toward the switch.