Heater motors
 

Hi guys,

Is there a difference between heater motors through the years? Is there a difference in them for rigs with and without AC? Mine conked out, it's not wiring and not a ground issue, so I guess it's time to replace. It's starting to get chilly in my '71 and tired of wiping the window. I'm checking out the vendors.

-steve

Re: Heater motors
 

mostly the plug for power is different through the years.. I've always had a few j/y pulled on hand.. they all seem to mount the same just the power plug sometimes is different..

Re: Heater motors
 

They are not all male spade style? I could always run a new supply line to match. Has there been any improvements through the years on these motors? I've seen the pitch on the cage blades has changed. I think the 88-98 year body styles uses a more aggressive pitched cage blade that moved more air making it a popular mod.

Re: Heater motors
 

I think the squirrel cage on the later ones (76-87) is wider but I think you can put the earlier cage on the later motors.

LockDoc

Re: Heater motors
 

oh maybe that was it. Are the motors the same through the years? Mine died. Since they seem cheap enough new I figured I would check the vendors. Just don't know if there is a difference between AC and non AC models, or if one is better than another.

Re: Heater motors
 

I can't tell you if there is a difference between A/C - non A/C but a lot of the motors are interchangeable. Some of the later ones have a vent tube on them but they will still work.

LockDoc

Re: Heater motors
 

I recall reading on here that there is a difference between the AC and non-AC blower motors. The non-AC blower motor spins slower than the AC motor and draws a lot less current through the fuse and switch (something like 6 amps for the non-AC motor vs. 16 for the AC motor). I think the stock fuse sizes for the blower motor are different for AC vs. non-AC to account for the different current draw.

The problem is that most of the aftermarket motors I've seen are AC motors, and if you put them in a non-AC truck without adding a relay or upgrading the switch it can draw enough current to eventually burn up the blower switch.

Of course, I've also read where guys have put a AC motor in and been real happy and not had any problems, so it could go either way.

Hope that helps.

Re: Heater motors
 

Thanks for your input Curt.

I have a new aftermarket fuse pane and harness but I am still using the original switch. Maybe I can get the AC motor and upgrade my switch too and be done with it.

I'll search the vendors.

LMC shows the same part# for both AC and non AC so I guess you are right sir.

Re: Heater motors
 

camrycurt is right - the heater blower draws 6.25 amps and the A/C blower draws 16.5 amps (from the 71 service manual)

Re: Heater motors
 

Ya thanks for the info guys. I looked at a couple vendors including LMC and the part number for both AC and non AC motors are the same from what I'm finding. If they are offering only the high amp model for both applications I guess I should upgrade the switch then too maybe? If I'm going to make an order what else am I forgetting? I did test both the motor lead and ground so I am pretty sure the motor conked out.

-steve