2003 Buick Century Blower Motor Problems

2003 Buick Century with 32,000 miles.

Problem: The HVAC blower motor works intermittently. When the blower motor is not working, none of the fan speeds will work, nor will the rear defroster work. In addition, I discovered that the cruise control will not work when the blower motor is not working, but the cruise control and rear defroster will work when the blower motor is working.

I have checked for blown fuses, loose wires, corroded contacts, and loose grounds.

With the ignition switch in "Run", using a volt meter to check circuits at the in passenger fuse block and by back-probing the connectors on the climate control module I have discovered the following: when the blower is not working, the "low blower" (brown wire, 20 amp) and HVAC (brown wire, 10 amp) will only get about 2 volts. When the blower motor is working both of these circuits are getting about 12 volts. According to the Haynes book, both of these circuits should be "Hot in Run".

The "High Blower" (orange wire, 30 amps) and "radio, HVAC, rfa cluster (orange wire, 10 amps) circuits are always getting about 12 volts. These circuits, according to the Haynes book, are "Hot at all times".

Do the "Hot in Run" circuits get their power directly from the ignition switch, or is there a relay that they get their power from? My Haynes book is not clear on that.

Does it sound like I need to replace the ignition switch, or are there other possibilities to seek out?

Thanks,

Jay

Welcome to AF.

Your problem sounds like an ignition switch issue due to the symptoms.

Hi

I am Pete and I'd like to know how this problem was solved. I have exactly same problem with my Century 2003 , only my blower fuse shows 5 Volts. I checked blower motor, resitor, blower switch and they are OK. Thanks for any help.

Pete

Welcome to AF Pete.

Your problem also sounds like an ignition switch issue. It's a fairly common problem on these cars, and causes the symptoms the OP (and you) are experiencing. Other common symptoms are dash lights inop, ignition key not releasing, shifter not coming out of park and or the drivers information center blinking out/inop. Lastly, although these older posts have a lot of good info, it may be best to start a new thread to be sure your issue is seen by as many members as possible. some people don't bother to scroll down when they see a thread that was started over a year ago.

Thank you very much for your help richtazz

I have removed the lower steering console cover to have a look at the switch. I hooked the voltmeter to blower resistor output and pressed on the wires coming out of the ignition switch. Voltage jumped from 6 volts to 11.5 volts so it looks as though there something wrong with switch or connections. I repeated this a few times and even managed to get blower motor running, but every time I turned off ignition it went back to 5-6 volts. If I replace the ignition switch , do I have to replace lock cylinder and starter key as well?

Thanks

Pete