Blower motor high speed fix

[John Larkin]

I thought I was going to have to buy a new relay, the metal one that hangs on the a/c box. I separated it from the connector, gently pried open the 4 tangs and removed the metal cover. There is a set of contacts inside. When these contacts close, that is what gives you the high speed (4th or top switch position) blower. Dragging a piece of sandpaper through these contacts cleaned them enough to let the red wire feed 12 volts to the purple wire on the connector. Voila, high speed blower for $0.

FWIW, the voltages you see at the purple wire in the connector should be as follows: low speed 3.2v, 2nd speed 5.8v, 3rd speed 7.5v, and high speed 12.0 (maybe 11.9). The red wire 11.9v - 12.0v all the time with the key on. The blue wire should match the purple wire voltage.

Just thought I would share.

 

[BILL HAINES]

Thanks, had same issue, but different fix, my plug near the antenna plug was rusted slightly and not making good contact, a good cleaning fixed the problem....
(the main plug for the box assembly)
it's nice to help our fellow buick friends out when we find similar issues....

 

[ThikStik]

Yep, just like filing points in the old days. Our old relay is probably better quality than a new .

 

[williamsGN]

I thought I was going to have to buy a new relay, the metal one that hangs on the a/c box. I separated it from the connector, gently pried open the 4 tangs and removed the metal cover. There is a set of contacts inside. When these contacts close, that is what gives you the high speed (4th or top switch position) blower. Dragging a piece of sandpaper through these contacts cleaned them enough to let the red wire feed 12 volts to the purple wire on the connector. Voila, high speed blower for $0.

FWIW, the voltages you see at the purple wire in the connector should be as follows: low speed 3.2v, 2nd speed 5.8v, 3rd speed 7.5v, and high speed 12.0 (maybe 11.9). The red wire 11.9v - 12.0v all the time with the key on. The blue wire should match the purple wire voltage.

Just thought I would share.

Just fixed mine with John's procedure... worked good - thought it was the connector everyone speaks of, but it looked good, and with the wiring on the bottom connector almost unreachable to do a splice, this was what I tried instead and worked out... Thanks!