Blower Mystery... 1992 Lesabre (Getting COLD in ND)

My 1992 LeSabre Custom has had this blower issue for probably ~ 5 months, but wasn't an issue in the summer since a/c didn't work, plus it was very intermittent up until yesterday. :uhoh:

The first time it happened I had my blower cranked with the car running. I turned the ignition off, then back to the ON position. Everything came on but the blower. I left the car and started it several hours later and the blower worked.

From then on, very rarely, the blower wouldn't come on when I started the car, or turned it to the on position. Hitting the dash, bumpy roads, etc didn't seem to do anything, but the blower would come on after 2-45 minutes driving, or possibly the next time I started it.

Now the blower won't come on at all, and it's getting COLD here so I'm getting worried. The odd thing is that the blower has NEVER turned off once it's running, and never been weak or made any noises. It either comes on with the car, or it doesn't come on and starts after some random amount of time. :confused:

It seemed to happen the most if I would turn the car off, and then very quickly back to the on position. Relay maybe? And if so, which relay? (I lost the cover to the relay center on the firewall).

Thank You for you help!!!

Welcome to AF! Here is a layout of the underhood relay panel. Notice that you have two relays for the blower, one for the three lower speeds and one for high speed, All the relays are the same in this panel, so you can exchange one from another function to test the relay function. I suggest using the one for the horn for the test. If the fan works with the relay installed, you can get a new one at any parts store to replace the bad one. In addition, you could have a blower resistor, or wiring problem, but start with the simple things first. :iceslolan

http://img266.imageshack.us/img266/403/buickblowerrelay502cuq7.jpg

It has been my experience that when blower motors fail- they usually fail just as you have described- and never once thay are running- this means the blower is worn out. Next time it is not on- pop your hood and tap on the side of the blower with a blunt object- like a hammer handle- and see if it starts- this is one of my tests- If it runs- then replace the blower- the brushes are worn down too much to keep armature centered. You can tap on relays as well- to make them work.....

Thanks for the quick responses! It came on for the first time in four days just before I got back and read these (good thing because ice was forming on the pedals... hard to drive!), so I'm not sure there's much i can test until it's off again. If there's different relays for different speeds, shouldn't it work on at least one speed? Also, I can switch it off and on as many times as I like from the climate panel without problem, so it seems like it's just correlated with the ignition. I did try hitting the relays but hadn't struck the blower itself. I guess I'll give these a go when my blower won't budge. Thanks!

I had a similar problem. It was the blower motor itself. I suggest you replace yours as yours is probably old anyway. It is too cold to drag this out.

The next time the blower will not run, turn the switch to high-speed with the ignition ON and check the blower purple wire for 12v. This is also a good way to test the relay, but not necessarily the resistor, terminals & wiring function. Now, if you find 12v on the purple wire and the motor will not run after you tap it with a hammer, this usually points to a wiring or terminal problem at the resistor. You may have voltage, but not enough amperage (current) available to start the fan on high speed. The motor draws 18-20 amps on high speed and the contacts in the terminals must be clean & tight to carry the load, otherwise they will overheat. If the terminals have corrosion present, the heavy amperage draw can damage the connectors and wiring. Good luck, I know how the winters are in Fargo, been there -- done that!

A rubber mallet works good to tap the blower motor to get it running - if the brushes are bad. I replaced my blower on my 1999 when I had the same symptoms. I really had to contort it to get it it out of the firewall heh.

Thanks a ton guys!! I've never gotten such prompt helpful responses on Infiniti, Nissan, Pontiac, Mazda, or Lincoln forums (Yeah... 7 cars is alot to go through for a 19 year old). I'm sure the answer is in here, but I'm just waiting for it not to turn on again. Sometimes there's a good 3 second delay between when I start the car and the blower comes on... Don't know if that means anything but I appreciate the help! I'll definitely be giving back to this forum in my areas of expertee because of all your help! Thanks!