Thread: I keep "blowing" blower resistors

So I got a new battery and regrounded some stuff since my heat stopped working last week and all my lights got really really bright. Pretty clear its the Alternator now; it's a Bosch still under warranty so I'm waiting for a new one to come (only a year old too). Although the bearing spins freely I'm assuming voltage regulator is done. So anyways I just went to Autozone and got a new blower resistor to get my heater back on. Clicked it into the harness, and YES!! HEAT!! and then.... it worked for a whole 20 seconds longer and blew. For anyone familiar with the BR's, it blew right under that little white rubber circular piece. So since I was still in the parking lot, I thought maybe I had a dud and went back in, they gave me another one for free this time. Slid into harness, start car, heat working working.... and done. Blown again. I already checked the interior fuses they are good.

So my question is, do you guys think it's a bad voltage regulator in the alternator doing this? Sending too much power or something and literally "blowing" the blower resistors?

this sucks! It's like 30 degrees out and of course this happens in the winter!! Oh and for some reason, my climate control setting has NEVER worked on setting 4. I know a bad blower resistor is supposed to just stop settings 1-3, but not on my car, for whatever reason. So I don't even have that. I have to wait for my new alternator and get another BR and see if that was it, I guess. Although I'd love to know if any of you have had similar problems.

oh and BTW this is in my 92 SE-R VE, running normally otherwise, but I swear the wipers still seem to sweep faster than they should (too much power from the Alt?)

Absolutely. The regulator in the alt is not regulating the voltage and over-volting everything. I wouldn't run the car until I got the alt replaced.

If you must use the car and you need heat, replace the blower motor resistor again but leave your fan on 4. On 4 (high) the fan is receiving 13.8 volts or whatever your alt is now putting out and technically the resistor isn't even working. On fan settings 1, 2 and 3 the resistor is stepping down (or resisting) the voltage to the fan, but it can not handle the higher voltage and BOOM.

Okay. I'll leave it parked. I must have just been editing the part where I was saying how it's never worked on setting 4, good resistor or not. That's bizarre, could be the physical plastic switch though in the dash.

When I got my XE the fan only worked on high, classic burned up resistor. Replaced resistor and all was fine until one day it stopped working on high??? But in my case the lever for the switch is a little wonky inside and that's where the problem is.

Did you have the resistor mounted when it blew or just plugged into the harness and hanging? That sucker gets extremely hot and it is mounted up in the "fan box" to help keep it cool. If it wasn't mounted and being cooled by the fan that could be part of the reason it went out so quickly.

Yep same here for this car since I've had it for going on 3 years. Always worked 1-3, never 4. And never had to replace the blower resistor. But I just did 3 tries in 5 min, all blown.

I just had it hanging to see if it worked, but in all honesty it was about 30 degrees in my car, but for the next one I get I'll properly mount it

I have had 2 cars in the past that had coffe or soda or somethng in the 1234 lever in the dash.
I believe it was from someone having drinks in the cupholders and splashing in there.

Check it out...thats my theory.It would not blow a fuse either,unless you wiggled it around.

It being 30 degrees would not have helped keep that thing cool. It gets proper hot and it needs the fan. Just saying this may only be part of the problem. The over-volting is your #1 suspect.

Interesting.

I did notice something else. When I looked at the interior fuses, there are 2 for the blower resistor motor, both 15As. So I looked and 1 of them is a 15A but the other is a 20A. I'm wondering if that contributed to it allowing more power to get to it. I don't know how or why the 20A got in there; just got a bunch of new 15A fuses and will swap with the 20A and get a new resistor, actually install it in the spot with the screws, and see if that works.