Heater blower motor question....

[glock35ipsc]

Tonight I installed the new heater control unit that included a new switch to replace the old broken one, plus a new resister (just cause it was cheap). Before, and now, when the switch was in low, your could just barely hear the motor turn, on medium it sounded like low should, and high was somewhat close to what high should be.

I am getting good voltage to the switch. It's it possible that the motor is bad? I know it kind of sounds obvious, 'specially since it is all that is left, but I figured the motor would either work or not.

BTW, this is a non-A/C truck. Thanks for any ideas!

[lukecp]

Check the post over at Chevytalk...i replied to it over there

[Hutch]

glock35ipsc
If it worked better before, then make sure you have the correct resistor for a non-a/c truck.
From what I can tell you should not be able to switch the two.
You could re-install the old resistor if it is still ok just for a test.

[Hooter]

um some of the motors dont blow as hard as some others, the fans out of AC trucks have more umph

[Longhorn Man]

This sounds about right for a non-A/C truck to me.

[glock35ipsc]

My 70 works like what I consider to be 'normal'. When I say it barely turning in low, I mean turning like you were blowing into the squirrel cage, like there was maybe .5 volts going to it. It's definately not right. It also does this with either resister and either switch.

[mrein3]

When I changed over from non-AC to AC I had problems getting the high speed fan to work.
I finally figured it out to be a missing relay. In the process of figuring that out I found:
I get 3 volts for low, 6 volts for medium, and 12 volts for high. I don't know if these numbers are correct but my fan behaves as I expect it to.

Perhaps you could start with a volt meter and check what is coming out of the resistor block.

[glock35ipsc]

I wonder about adding a relay. Mine has the factory harness which runs from the switch (with one going to power) to the resistor, then one on to the motor.

FWIW, I picked up a new motor at AutoZone for $16.99 at lunch. Just as well, the other one is 37 years old!

[70 net440]

Here's what I found with my kid's '67. I replaced all of the cables and levers and had no high speed, just low and medium. I bought a new switch and discoverd that the new fresh air cable had bent and kinked. I don't know if I routed it wrong or what. I disconnected the cable from the switch lever and moved the fresh air duct to open. I now have all three speeds on the switch and having the fresh air duct open has helped a lot. You can check the motor by running a jumper wire to the motor to see how hard the fan moves air. You might also take the heater box out to see if you have a pack rat's nest in it. By the way, the motor still moves about half as much air as my wife's '63, so I will be upgrading to an A/C motor down the road.

[glock35ipsc]

Well, after digging into it a little, I actually found about 3 pack rats nests!! So, not wanting to spread the hantavirus, I completely disassembled to heater system, cleaned all the inside tin parts and the outside unit in the solvent tank, rinsed and dried, then primed and painted the inside parts semi-gloss black. The outer unit looked new after the cleaning. Got a new motor from the parts store for $17, and since the squirrel cage was chewed up, I found one in Dad's parts pile that was like new. Have new gaskets coming to put it all back together, so it should work awesome now!!