Help again anybody, I replaced the fan relay switch due to the heater blower NOT working, Actually, I replaced the switch on the console, then the relay switch..Fan still not turning!! However, what i discovered was @ the fuse box under the dash. one side of the fuse box had "NO" power at all. The same side that the heater fuse is on. I don't feel too bad because all 30 year parts have been replaced Any suggestions??

 

What year is your car? One of the most common reasons a blower motor quits is because the black ground wire that attaches to the motor's flange is loose or broken. Check that ground wire and also send 12 volts directly to the motor's terminal to see if the motor even works.

 

OMG

 

Some fuses have power on both ends even with the key off.....some fuses only have power when the ignition switch is turned to the RUN position.

My fuse block had no power on half of the fuses with the key turned to the RUN position. When I bumped the fuse block with my palm voltage would show on the meter.

I probed the main wire going into the firewall to the fuseblock and it showed 13 volts on my volt meter. I also probed the main supply wire going to the Ignition switch and the main supply wire that went from the Ignition switch to the fuse block. Then I removed the firewall connector bolt that held the engine/starter harness to the fuse block and pulled the connector out so I could see the terminals.

The terminals that plugged into the back of the fuse block were badly corroded/beyond repair. I had already installed a new fuse block because the dash wiring was shorted/ruined. I then installed a new engine harness (since....I have learned that I probably could have bought several packs of terminals and spent a day cutting off the old terminals/crimping new terminals on and inserting them into the connector....which could have saved me about $200)

Anyhow.....the problem was solved.....I'm not saying it's your solution, but if all else fails, remove the firewall connector and check the terminals for corrosion. Also shine a bright light into thefirewall opening where the connector was.....look at the terminals on the fuse block to see if they are corroded.

 

Hello toobroketoretire, My vehicle is a 78 Vette. The first thing i checked was the fuse, and from there i went to the motor, The Motor works Great. I then started exploring other possible solution, I replaced the console switch and the Fan relay switch. I'm looking so,... the problem can't hide for long. Frustrating for now I will now..... check to see if the dead side of the fuse box come to life after i turn the key on...

 

Hello Doorgunner, Excellent advice, I'll check the fuseBox once i turn the switch on. I call myself checking the console switch where the 12 volts goes and there were "NO" power there as well. I'm gonna proceed with a few more tests....Thanks you sir!! I wasn't a door gunner but i was in Viet-Nam in 67. Got to see Bob Hope and Robert Mitchum