Car repair- heater fan

Factual Questions
1

My car is a 2000 Chevy Malibu.

Back in december I started having issues with my heat. The blower fan was working intermitantly. This kinda sucked as I live in MA. I found hitting the insulation between the passenger foot area and the fan helped persuade it to work more often then not. Eventualy doing this didn’t help as much so I got motivated enough to work out in the cold to try and fix it. I’m 6’1" standing on my head to get to it wasn’t much fun either.

I pulled the fan out and found an overly complex plug for conecting 2 wires to the fan. This by turning the fan on and off and testing with a volt meter I made a pretty educated guess the fault was do to bad wiring in the plug. I made a few phone calls and to the parts places and didn’t get far in finding the same silly plug. So I just cut the plug out and crimped in a couple wire thingies that coul slide over the motor tabs. Playing with it a bit I found I wasn’t getting the high ranges. I figured some heat is better then none and was a bit cold so that was that till spring.

When I was putting the motor back in I noticed a little circuit board up in where the fan is goes. It had a small scorch mark on it. That explained the range issue to me.

A week or so after the operation I lost my heat completely again. I kinda gave up on fixing the problem and just finished off the freazing winter. The car was a little warmer inside if I went down the highway.

Well by the time spring hit I didn’t really need heat. Why not procratinate more?

Now its summer and I rather liked having my AC so today I decided to fix the problem. It was an issue trying to identify and locate a replacement curcuit board thing. It is a resistor. Got the part. Stood back on my head took everything apart again and swapped out the curcuit board. Tested my fan and that works fine. I touched the resistor in this process and found it was really hot. Not like melt stuff around it hot but enough to burn your hand a little.

The resistor is located inside the fan area for a reason I’m guessing. Is it because it would normally get hot like that? Should I be concerned its just going to get toasted again and check into a wiring issue causing the hotness?

2
  1. Did you buy a resistor of a high enough wattage?
  2. The motor may be going bad and drawing too much current.
3

The resistor I picked up is the replacement part the computer spat out for my car. Could be wrong I suppose, but I don’t think so.

The motor could be going bad I’m not sure how much current it’s suposed to draw.

4

Based on my past similar experience, I’m betting that the brushes in the fan motor are worn. Every time you tap around the fan motor to get it started you’re edging the brushes a wee bit closer to the commutator. There may still be a small space between them however, small enough to allow the 12 volts to arc across creating a lot of heat.

I’m not sure if that could explain a hot resistor though.

5

The fan wasn’t getting hot at all just the resistor

6

Blower motor resistors typically are constructed of open wire coils, like toaster heating coils, and typically get plenty hot. I’m not seeing anything in the story that indicates a problem at this time.