hey guys i got this problem with my blower motor. basically it won't work. I hooked the blower motor itself up to the battery to test it and it will run so its not the motor. I replaced the blower motor relay and still nothing happens. I tested the wires with a meter to make sure they are running straight through up to the point were they plug into the relay and they are all good. I also tested the fan switch and its good. i can't seem to figure this out plus i am freezing too lol. and what exactly does the blower motor resistor do? maybe that might have something to do with it? any help would be appreciated

thanks kidcamarosc

__________________________________________________

88 Sport Coupe
160,000 and still rollin
Black w/ Gold GFX
14 x 3 KN open element
hooker catback
rest all stock

__________________________________________________

 

The resistor pack allows the fan to run at low and medium speeds. If the resistor pack were the problem, the fan SHOULD still work when set at high speed.

You said the switch tests as good; have you tested to see if 12v+ is available at the switch, when the key is on?

 

maybe its the heat/ac fuse??? just a thought....

 

inspect the blower motor ground, is often corroded on older cars.

 

Ground was bad on mine.

 

what if ground is ok and switch is ok ? thne what ? when is the purple wires supposed to be hot at the relay ? they never are....

 

black wire @motor is supposed to always be grounded. the purple wire is supposed to be hot when blower motor is turned on.

in all positions except high, the blower motor gets voltage supplied through a resistor pack which slows the motor down to proper speed. in high position, voltage is supplied directly from battery to blower motor through the high speed blower relay.

 

thanks 2v, i have two more Q's then Im done lol

why does the black ground wire come from the firewall harness through the relay and split off to the blower motor, and what does the purple feed off of, the switch int he dash or ? aparrently since the purple is dead all the time no matter where the switch is placed then the switch must not be getting hot source, or it is bad

am i right ? i hope, or Im totally lost.,. i have no ground source in the black and no hot in the purple, hmmm.....

what woudl you do if you were freezing and had this set of symptoms ?

thanks

 

well hopefully kidcamaro has his blower motor problem figured out because i removed my heater a/c control panel today and messed around with it testing for hot, and the brown wire from the fuse panel to the back of control panel is hot, so... and the yellow and blue and orange are all hot depending on position of the fan switch so,... all shoudl be good, and thne whe i tested for hot out under the hood i have hot out of the purple all of a sudden, so... hmmm... but i have yet to reinstall the relay, which i will do tommorrow, so it better work now, oh and i gotta reconnect a new ground from car to blower motor case, since for some reason the exisitng ground wire isnt grounded, or at least shows no ground with tester...

*crosses his fingers...
thanks

 

with blower motor relay removed, all fan speeds except for high should work.

ground for blower motor is on the back of the cylinder heads. clearance is tight between the block and firewall. as a work around, strip some insulation off the blower motor black wire & solder a jumper wire to it. attach other end of jumper wire to a more accessible grounding location. idea here is that other circuits share a ground with blower motor circuit and will now be grounded through new chassis ground wire that you installed.

as for purple wire becoming live only after you wiggle the electrical harness a certain way, i'd suspect that the blower motor resistor pack connector is corroded or cracked. resistor pack connector will be on top of heater box in engine bay, will have four heavy guage wires, yellow, tan, light blue and purple.

 

or you could take a test light, clip to the terminal at the harness(power) and touch the ground wire attached to the case if it lights up then tada good power and ground, if it dosent then connect the clip on the test light to the door striker, scratch back and forth so you get a good ground then touch the power wire again, now if it lights up then you have a bad ground at the blower motor

 

problem with this method is that test light draws only a small fraction of an amp, by contrast the blower motor draws in excess of 10 amps. your test will show if ground ring terminal has broken off completely, but will not show if grounding point is corroded.