Heater Motor?

[Craig Nedrow]

Not often do you see that kind of six cyl, mostly in heavier trucks, or busses. Is the engine original? Got my eye on a truck similar to yours, that has been setting for year. Squares are habit forming.

 

[Shorty81]

The 250 six was used in quite a few 1/2 ton trucks. The 292 was used in pick ups and a lot of medium duty trucks.

 

[ulm4lyf]

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

annnnnnd now it's on backorder. Got an email saying 4-6 weeks until they get some more.

 

[79c10paintedtwice]

Thanks for everyone's reply. I'm going to install a cutoff switch.

 

[Rickf]

A dead give-away would be the lack of "off" on the blower speed switch.

 

[Charlie]

Thanks for everyone's reply. I'm going to install a cutoff switch.

For the blower motor not to run all time, need to remove the upper wire from the connector on the resistor. Mine is the yellow wire in the pic.

 

[AuroraGirl]

For the blower motor not to run all time, need to remove the upper wire from the connector on the resistor. Mine is the yellow wire in the pic.

Strange... what wire is that meant to be? I wonder if that applies to all years or no ac, ac
I modified mine by putting a switch inline to the speed switch, found a way to do that on-off lol

 

[Charlie]

Strange... what wire is that meant to be? I wonder if that applies to all years or no ac, ac
I modified mine by putting a switch inline to the speed switch, found a way to do that on-off lol

That is the LO speed for the blower. If you have 4 speed fan switch with no off position. Other years may differ. I do have AC but not sure if that matters.

 

[79c10paintedtwice]

If removing one wire will eliminate just low speed, that's the way to go.

 

[Grit dog]

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.

Wow dude. That truck is niiiice!

 

[79c10paintedtwice]

Thanks, still stock 6 cylinder , 3 on the tree. Not taking any chances with passing smog in CA. Could use posi upgrade.

 

[AuroraGirl]

That is the LO speed for the blower. If you have 4 speed fan switch with no off position. Other years may differ. I do have AC but not sure if that matters.

I believe my fan switch is a 3 speed switch (early no AC ) but I could be remembering wrong.
AC trucks got more speeds by default usually , sometimes the wiring to all the components would be different by a lot as well

 

[79c10paintedtwice]

I'm going to try removing the low speed feed from the resistor module. Low speed is not going to defrost a window.

 

[AuroraGirl]

I'm going to try removing the low speed feed from the resistor module. Low speed is not going to defrost a window.

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heat only 1979 above

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AC system 1979 above

 

[AuroraGirl]

I'm going to try removing the low speed feed from the resistor module. Low speed is not going to defrost a window.

So unless im reading the diagram above I posted wrong(heat only 1979) , I think the wire you are looking for is brown? I dont recall what color mine is, but im not checking lol..
There are 2 brown wires to the blower switch, and best I can tell the one that goes to the bulkhead for the blower motor is the one needing a switch. but do check that to be sure.