A/C and heat not working - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sanjac272 · 02-02-2016, 09:09 AM

When I try the A/C or Heater I go no blower action. Have checked fuses and replaced relay on the firewall. Any troubleshooting ideas would be welcome.

1978 GMC K15

Thanks

**MikeB** · 02-02-2016, 10:04 AM

Try applying 12 volts directly to the blower motor, assuming the connector is easily accessible. It is on my 82 C10 without AC.

02-02-2016, 09:09 AM	#1
sanjac272 Registered User Join Date: Oct 2015 Location: Montgomery, TX Posts: 4	A/C and heat not working When I try the A/C or Heater I go no blower action. Have checked fuses and replaced relay on the firewall. Any troubleshooting ideas would be welcome. 1978 GMC K15 Thanks

02-02-2016, 10:04 AM	#2
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,597	Re: A/C and heat not working Try applying 12 volts directly to the blower motor, assuming the connector is easily accessible. It is on my 82 C10 without AC. __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!



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