My heater/A/C blower motor does not work on the fastest setting/position. It works on very slow and medium speed but then shuts off when I turn the switch to the last/fastest position.

I bought a new switch, but this still did not fix this issue.

Is there a relay that is responsible for the high speed setting or something? I'm clueless.

Any help would be greatly appreciated.

 

blower motor resistor.

 

Yes. The resistors are in the low speed settings circuit.

JamesC

 

I think it's the relay, not the resistor pack. The relay runs high speed, the resistors are used for the other speeds.

 

... and it's easy to find because it's on a bracket bolted either to (A/C cars) or near the blower housing. There is also a fusible link for the bugger as well...

 

OK, thanks guys. So the resistors are for the low speeds, and the relay on that bracket right by the blower motor is for high speed?

And where is the fusible link for the darn thing?

 

On the starter

 

If the fusible link were bad, though, the thing wouldn't turn on, period...right?

 

I think that fusible link is for all the accessories, not just the blower.

 

Everything that is connected to a constant 12v source goes through a fusible link

Depending on the engine type, there are 3-7

 

Don't know about the V8's at the moment (don't have my FSM with me here), but my fusible link for the blower fan is actually at the junction block where the small positive cable connects along with the alternator BAT wire on stock cars... Yes, it's the stock location.

:edit: And yes, the blower motor is on its own fusible link...

 

Right, but the blower motor wouldn't turn on AT ALL, if the fusible link was bad. I'll change the relay first then post what happens.

 

Well I tested the relay with a battery and jumper wires, and it made a clicking sound, so I assume the relay is good.

I cleaned the plug and the relay terminals with electrical cleaner. If that doesn't work, then I am stumped.

 

Check the following link for some great suggestions:

https://www.thirdgen.org/forums/elec...aro-rs-no.html

JamesC

 

Actually, there are 2 separate circuits for the blower motor... The fusible link for the high speed is ONLY for the high speed. When I originally installed my 91 harness, I didn't have the high speed wire set up for the blower fan. The blower had all speeds except for high speed.

Just because the relay clicks doesn't mean it's good...