Hey guys, I recently was given a 96 Bonneville SE and have been slowly fixing all of it'* problems. I searched a couple of times and did not see my specific problem addressed.

The blower speed works on the 1st three settings but high goes dead. It is a manual control system. Does it sound like a blower module problem? I read it is located under the max fuse center and did read how to remove that.

I have spent money many times on parts that did not fix the problems when I was younger. Was hoping to avoid that by educating myself in here. This internet stuff really helps out!

Are the modules available at most auto parts stores?

Thanks guys.

You probably need a new blower control module. If you want to make sure its not an issue with the blower motor, you can run 12 volts direct to the motor to see if you get full speed.

Well I ran a wire from the positive side of the battery and touched it to one prong of the blower motor with the plug removed and nothing. Tried other prong and nothing. Measured voltage of the plug and it was 12V on all settings except high which went to zero. When I pushed plug back on, blower motor runs on three lower speeds. Then tried 12 v wire again thinking I did something wrong....nothing. Puzzles me it won't run with 12v direct.

If I recall, the lower three speeds are through a relay and the resistors. The high speed is a different relay and is direct power from the battery to get the most amperage for higher speed.

You can switch same part number relays to see if the relay makes a difference. Most of them in there have the same part number, if not all.

http://i86.photobucket.com/albums/k1...lay502chj8.jpg

Other way to test blower motor itself is to provide a separate ground wire to the plug on the blower.

I would have to check the factory manual to see if the high speed uses a different ground than the other three lower speeds. Doesn't seem logical.

imidazol97'* advice is good. The fan probably didn't run because you not only have to supply 12V to the positive lead, you also have to provide a good chassis ground to the negative lead.

Thanks guys for the great advice! I made up a couple of jumpers and grounded the one and ran the other to the battery and the fan ran at high speed. So I know it is good now. The relay pictured in the schematic you provided (thank you very much) was a one of part number. My SE has 5 relays but the high speed blower relay is the only oddball numbered one. So I did not exchange it out. I will pick one up tomorrow and see what happens.

Also, is that small rubber hose connected to the blower motor and going to a connection on the firewall important? It'* about three inches long. I accidentally knocked it off while removing the blower motor plug and it looks to be dry rotted. Tried hooking it back up best as I could but it seems awful loose now....?

Again thanks for the help, it has really saved me a bunch of time trying to figure this stuff out.

Dave

I am not sure if there is a vacuum hose, or just a vent. Start the car and see if there is vacuum at the connector on the firewall. Is the hose thick walled (vacuum line) or thin (vent)? In either case, replace it with a new one.

Good to hear your motor runs on full. We might not have found the problem yet, but it sounds like you are narrowing it down. Keep us up to date with what you find and any other questions you have.

Now you've all done it. I had to go get my Buick service manual for 1998. It also shows Olds and Pontiac.

I am assuming the SAME circuits are used for 1995.

The relay for the manual blower system is a different relay from the others. It has terminal 87 which is the high amp terminal. It comes through fuse 3 on the relay center, a 30 amp fuse. It says right hand underhood.

The relay also contacts terminal 87A which is the lower power circuit that gets 25 amp from fuse 5D in the instrument panel fuse block. That supplies the 3 lower speeds and when switched to high applies voltage to the relay switching it from the 25 amp circuit to the 30 amp circuit.

The SAME wiring supplies the blower from the relay on to the blower. The blower uses only one ground which is terminal B on the blower motor. Your motor should have run the same but when you disconnected the terminal socket for both A and B from the blower motor, there was no ground. You do have to supply your own ground!

Easy check is fuse 3 in the relay center. Hope it'* blown. Might question why it blew, but that'* an easy replacement. I might indicate impending blower motor failure with age and high current loads.

it could indicate the relay is stuck on the 87A contact and not switching under power to the other terminal. Could be primary circuit blown not pulling the relay or could be the contacts are physically burned to the most-used contact.

Hey guys, well I had to run to town for the Mrs. so I stopped and picked up a relay. Installed it and now the fan works at all speeds! Thanks for all the advice, I really appreciate it when others take a little time to help someone out. I try to do the same when I can. Now on to the brakes!

Awesome. Another one in the win column, and I don't think this one cost too much. I like those.