help with heater/fan not working

[69ChevyRazorback]

alrite guys, im sure alot of you will know exactly what I need to do to fix my fan problem. it isn't working right now. Whenever I move the "fan" switch to on, it makes a short squeeling sound and then stops and nothing happens. anyone know what this problem is? do i need a new fan motor or something else???

i have a 69 c10

[JimKshortstep4x4]

If the fan is "squeeling" then the motor is probably bad. To check, jumper the fan motor direct.

Does your truck have AC?

Jim

[ChevLoRay]

Sounds like it is a bad motor to me, too. The big issue with really knowing is getting to the motor, and that means you have to pull the hood hinge on the right side to get the motor out. I changed mine, all by myself (I'm a a big boy, now) and put in the new one. Heck, just be careful and make sure you mark exactly where your hinge mounts so you can get it back in the same place. If you need help, be sure to get it. You gotta prop up the hood before you take that hinge out, so don't forget or you'll have a serious headache.

But, I'm betting that the motor is bad. O'Reilly's has them and they aren't expensive.

If the motor didn't work on high speed, there's a relay that may be bad, too. Funny that the lower speeds work, but not high speed, huh?

[Luvlegs]

try sliding the lever back a little - mine does it if I slide the lever too far over - a slight move back and it works fine. The squeel I hear is more like a quick "I'm moving" from the fan.

[69ChevyRazorback]

man thats alot of trouble to change out the fan motor. I have to remove the hood hinge? man thats gonna suck. And no I dont have AC. and my fan/heat doesn't work on any speed. I can move my lever from off to all the way on and it just makes a little squeal and then nothing.

[Joeys Toy]

You can take an ice pick and punch a small hole in the fan motor housing at the top of the small bump in the middle (where the motor shaft is and oil the bushing. May want to loosen it up with WD - 40 first. An old mechanic showed me that trick and it has worked so far. And no, I am not cheap! The proper term is "Frugal".

[ChevLoRay]

Originally Posted by 69ChevyRazorback

man thats alot of trouble to change out the fan motor. I have to remove the hood hinge? man thats gonna suck.

It may be that the fan motor on a nonAC truck is easier to get to....God knows that I try to live life as difficultly as possible. If so, it should be easily removed. Hopefully, someone on here will chime in and lay some good news on you. But the heater motor/blower ass'y is close to the right fender/hinge. Pulling the hinge really isn't as difficult as you may think. Like I said, scribe some marks that will help assure your ability to reinstall it in the same position and use a prop to hold the hood up on that side. Use something to protect your paint, if you have to in case the hood slips while the hinge is off. Honestly, it isn't that much of a chore. An afternoon will find you getting it done.

[69ChevyRazorback]

Originally Posted by ChevLoRay

It may be that the fan motor on a nonAC truck is easier to get to....God knows that I try to live life as difficultly as possible. If so, it should be easily removed. Hopefully, someone on here will chime in and lay some good news on you. But the heater motor/blower ass'y is close to the right fender/hinge. Pulling the hinge really isn't as difficult as you may think. Like I said, scribe some marks that will help assure your ability to reinstall it in the same position and use a prop to hold the hood up on that side. Use something to protect your paint, if you have to in case the hood slips while the hinge is off. Honestly, it isn't that much of a chore. An afternoon will find you getting it done.

thanks ray. I bought a new motor from autozone today. looks like i will have to remove the hinge but no biggie just a couple of bolts and it should be easy to change ou (hopefully). thanks for your help and everyone else

[70STOVEBOLT]

Quote:To check, jumper the fan motor direct
How do you do this? My fan has squealed off and on for the last couple years, and it finally gave out this week. And, of course, it's the coldest its been here. TIA for any help.

[Longhorn Man]

to jump it, just run a wire from the battery positive directly to the plug on the motor. When you put the wire on the terminal on the motor, if it runs, then the blower is good, if it still doesn't work, then you have to start some real troubleshooting tests.. checking the switch and the resistor, and possibly even the harness.
As for pulling the hinge to replace the blower motor... that's nothing. Some new cars, you have to remove the DASH.

[70STOVEBOLT]

Andy, thanks for the tip. I replaced the motor last night (it took about an hour), and it still did not work so I checked the fuse box, because I found the fuse blown after the motor stopped yesterday. The "HEAT" fuse was ok, but the "AIR COND" fuse was blown. I replaced it and the motor worked. This morning it stopped working again on the way to work, so I checked the fuse box again and the "AIR COND" fuse is blown again. There was a 10 amp fuse that came out so that's what I put back in last night. This morning I noticed it should take a 15 amp so that's what I put in and it is working currently. I am confused though. Why would there need to be a fuse in that slot since my truck does not have A/C? Can anyone explain this to me? Sorry to be so long-winded.
Any help would be appreciated.

[68gmsee]

Originally Posted by 70STOVEBOLT

.........Why would there need to be a fuse in that slot since my truck does not have A/C? Can anyone explain this to me? Sorry to be so long-winded. Any help would be appreciated.

Engineers are notorious for taking shortcuts. If A/C was projected on a lot of the trucks built, it wouldn't cost (back then) that much more to make all of the truck's fuse boxes the same. Then you wouldn't have to mess with having two separate boxes.

[Longhorn Man]

it's the same spot, A/C or non A/C... a/C trucks got a bigger fuse in that location.

[70STOVEBOLT]

If the 15 amp fuse doesn't cure it, what else should I check? I am getting power through the fan switch
would the resistor on top of the heater box have anything to do with it, or is there likely a short to ground somewhere?

[Longhorn Man]

I wonder if they gave you a blower motor for an A/C truck. 10 amps is all the non a/c blower needs acording to the fuse box print. An A/C piece would pull more amps due to being made to blow harder.
A short to ground would pop the fuse instantly.
For some reason, you are drawing a bit too much in the amperage department. If the 15 amp fuse holds on, then i just wouldn't worry about it honestly.

[mrein3]

There are two posts going on here. It sounds like 69ChevyRazorback's squeeling fan is a bad fan motor. Run a jumper from the battery + post to the plug and verify that it still squeels. If it does, and I'm guessing it will, replace the motor.

70STOVEBOLT has an open wire some where that is causing a short and popping the fuse. A REALLY old mechanic once told me to simply put in the largest fuse you can find and then just look for the burnt wire (too big a fuse won't pop and will melt the wire that is shorting - not a process for the faint of heart because you may burn down your truck and the garage you are working in).

In my opinion these trucks were wired with wire one or two gauges too small. An overkill fix for 70STOVEBOLT would be to pull the wiring behind the control, replace all the undersized wire with fresh wire that doesn't have cracking, 40 year old insulation, which would probably catch the faulty wire. If you just want to get it working, trace all the wiring in the fan circuit, find the open wire, replace it, and move on.

I have observed that the plugs behind the controller on these trucks melt after 40 years of all that current running through wire that isn't big enough. This causes shorts which in turn pops fuses.

[70STOVEBOLT]

15 amp fuse appears to have taken care of the problem, it worked all the way home last night and all the way to work this morning. I tried all the fan settings without any problems. I don't remember when I bought the motor if they asked about a/c or not, it was 2 or 3 years ago when the motor first started squealing. Thanks guys.