my heater fan

[camaney]

HI everybody.ok i have a 70 with a/c and my heater fan is not working.I check the fuse, check the wires to the blower relay with swith on and the only wire that has power is the blue one even on high I also check the fan straight to batt. and it works so now whats next. do you think the relay is bad. thanks

[Mike Quillici]

Hello Neighbor. I just went through a whole bunch of heater fan drama myself. Here is a link to the thread that I started a few weeks ago. If nothing else, check out the wiring diagram. Hopefully that will be of some help.

http://67-72chevytrucks.com/vboard/s...d.php?t=375310

[camaney]

Thanks mike I allready check that post i just wonder if anybody has had the same problem like that I dont want to buy that relay before cheking if anybody had that same problem before

[LockDoc]

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Make sure there is a fuse in the A/C slot in the fuse block and it is good.

LockDoc

[camaney]

the fuse is good. anybody else with similar problem in the past?

[mrein3]

Originally Posted by camaney

the fuse is good. anybody else with similar problem in the past?

Yes. Take a good look at the connector behind the fan speed switch in the dash. In my opinion the wires are too small. Add 40 years of operation and bad connections (heat) and things begin to melt. Be prepared to re-do the whole connector back there.

[fixit-p]

The blue wire comes from the resitor to the N.C. circuit of the blower relay the common side of the circuit is the purple wire which goes to the blower motor the large orange wire (N.O. circuit) should have full battery voltage and plugs into the cig port on the fuse block if you unplug the relay plug and jump the purple and blue wires together the blower should come on if not check the purple wire to the blower for oen circuit also you can jump the 12ga orange wire to the purple and blower should come on if you restored power to orange and purple wire traced ok to the blower motor. The smaller 16 or 18 ga orange wire is the control side of the relay and should have power with switch on high if not trace back to switch.

[camaney]

ok fixit I did everything you said and I do have power for big orange wire also small orange with switch on and blue but not pple also jump a wire betwin pple and blue and the fan works what else should i do

[fixit-p]

Relay is bad, those test verify this.

[camaney]

thanks a lot fixit and everybody for helping you guys are great