The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Heater Motor Rusts Out -Seized-

Hey...

Do any of you have an issue with your heater motor getting wet and rusting/seizing up? This seems to be happening on my 1965 Chevy dump truck that spends it's life outside. I replaced the motor twice with the same results. The only thing I notice is the replacement motors have a quarter sized hole on the motor housing I assume for venting. I block the hole up like I always have but it still seems to get water inside because the motor is seized and there is evidence of rust inside as you look inside the hole.

Here are my thoughts:
- I just replaced the motor with an older (I assume stock) motor that does not have a hole in the motor housing making me think the hole should not be there.
- There is a hole in the blower housing. Maybe I had the motor clocked wrong and covered the hole meant to let any water out?
- Maybe because the motor hangs upside down in this year truck rather than on it's side like others, you either need a blower motor without the hole -or- I should expect these replacement blower motors to fail because they were really designed to be mounted on their side.

Anyway, any help would be greatly appreciated.
...Russ

You are talking about the fan motor I presume. It installs upwards in our trucks. Your experience with seized motors is a first I have heard of. Are you sure your heater core is not leaking? But this does not make sense either since the motor shaft is sealed.
I will be interested in the responses also.

Hi... Yes the fan motor... I do not think the heater core is leaking because I do not see the tell-tale sign of green. I also looked for any rust holes allowing rain in, but found none.

I believe those motors with the hole in the housing are also supposed to have a rubber vent tube with a grommet-style groove installed in the hole. The ones I've seen with the vent wrap around the motor housing so the bottom of the vent tune points down.
Jerry

Is that vent tube hole actually a drain? Is it possible the motor is creating condensation from heating up and cooling off which is then sitting in the motor?

I’m totally guessing here...

Hey Jerry and Fox...

The replacement motors come with a plug now to cover the hole. I have used a home made plug in the past, but it just seems the quality of these motors might be the issue now. I believe they probably do well on there side (horizontal) but not so well when used upside down (vertically).

I do remember seeing a rubber vent tube in the past (I have had these years trucks for over 30 years), but haven't in a while. I wonder if that would vent and also help prevent water from seeping in???

One more comment to Hambone... Another reason I know the heater core is not leaking is the fact the defroster works as expected. Usually if the heater core is leaking, it will fog up the windshield when the defroster is on.

On a side note, the replacement "original" blower motor I found seems to be working for now, but it is making noises (age?) and I expect the need to replace it so I bought another new blower motor which came with the plug, so the mystery will continue... I guess I am getting tire of replacing the motor every year or every other year at the start of fall when you tend to need the defroster.

A small bead of RTV sealer around the plug might be a good idea, to be sure any rain or condensation can't get into the motor windings.
Jerry