Heater Motor?

[79c10paintedtwice]

79 C10 6 cylinder. Heater motor will not shut off when ignitionison. 3 speed switch works fine. Can not find another switch in the wiring diagram. Is there a switch actuated by the sliding controls?

 

[Memaloose]

It never shuts off on my '75. I had a '79 too same thing.

 

[PrairieDrifter]

Yup as said above, 70's trucks it never shuts off. I've opted to wire in a toggle switch inline.

 

[ulm4lyf]

Mine is always on low. No other speed works. I've ordered a new 4 speed switch.

 

[Snoots]

It's NEVER supposed to be completely off. That's what the 'flo-thru' ventilation system is.

 

[Tinker]

The system is designed to run at all times (when key is on).I believe it started in 74 or 75. As mentioned above a toggle switch could be wired in to stop that function.

 

[79c10paintedtwice]

It's NEVER supposed to be completely off. That's what the 'flo-thru' ventilation system is.

Good to know. As others mentioned, a switch would solve the issue. It's a new motor, I'll let it run for a while.

 

[Memaloose]

It used to be open wing windows were the "flow through ventilation".

 

[WFO]

I put a brass ball valve on the heater hose of my 77, so it at least wouldn't be hot air in the Summer.

 

[85K304SPD]

We used to call it the summer heater, or something like that, "back in the day". It sucked to be the guy that had to ride in the middle. Oh well, we were Cruisin'. That is all that mattered.
I don't think that my '85 does that like the '80 that we were cruisin back then.

 

[Turbo4whl]

We used to call it the summer heater, or something like that, "back in the day". It sucked to be the guy that had to ride in the middle. Oh well, we were Cruisin'. That is all that mattered.
I don't think that my '85 does that like the '80 that we were cruisin back then.

Yes, my 1974, no blower off. My 1982 has blower off. No AC in either truck.

 

[79c10paintedtwice]

Thanks for the heater blower history lesson. It will now run forever. I did find a wiring diagram in my 1979 service manual. A lot easier to read than the reprinted diagrams I bought online. Unfortunately, first try with heater hoses connected, I'll be changing the heater core.

 

[Shorty81]

Wow!! That is one nice looking truck!!

 

[79c10paintedtwice]

Thanks. The local high-school auto class had painted it with school bus paint. I sanded to metal and primed with Eastwood roll on primer. Ended up spraying, too much roller stipple.

 

[AuroraGirl]

It used to be open wing windows were the "flow through ventilation".

yes but standard feature that even the competition has means thats not something you can put in a brochure to evoke feelings of features and advanced and on-top-of-it features like FLOW THROUGH VENTILATION. Vent windows being open? NOISY. FAN MOTOR BEING UNABLE TO TURN OFF AND HUMMING AND DRAWING POWER AT KEY ON? The. Future.*

*until they undid that choice in like 83 or whatever and called that a notable change