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Ask Dan Your Own Question
Dan, Technician
Category: Car
Satisfied Customers: 23950
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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Resolved Question:

99 Oldsmobile Intrigue, blower motor works on speeds 1, 2 and 3 but not on 4 (high). Also have problem with the ac cycling on and off (it's not low on refrigerant). No specific instances that would seem to contribute to the ac cycling on and off. Happens with city stop and go or highway driving. When it’s running and the ac stays engaged it blows close to 40 degrees from the vents. Typically has more problems the hotter the outside temp. Installed a new cabin filter & blower resistor. The A/C problem of cycling on and off has gone away, but fan still does not work on high. Installed a good used a/c control but fan still does not work on high, put my old control back in. Does not have automatic climate control, just standard controls. Not sure what to do from this point. Change the blower motor??
Submitted: 7 years ago.
Category: Car
Expert:  Dan replied 7 years ago.
The orange wire between the heater control and blower motor resistor controls high speed. Considering you replaced the control and the resistor then run a new wire and problem will be fixed. Let me know if you have questions, thanks.
Customer: replied 6 years ago.

Visually inspected the terminal blocks for damage, found none. Checked the orange wire for continuity between the two terminal connectors and it check out ok. Checked the other wires between the two terminal blocks and those were good as well. When I first started trouble shooting I replaced the climate control assembly first and tested high fan speed. After that did not solve problem I replaced the blower resistor which had obvious signs of being defective (dark spots on the board). So I am thinking that I possibly burned up the circuit board inside the used replacement climate control unit since I installed and tested that before replacing the blower resistor. No sure how familiar you are with the inner workings of the control but I took one apart for inspection and the fan control knob has two copper fingers (brushes?) that drag across a circuit board inside the control as you turn the knob. Your thoughts?

Expert:  Dan replied 6 years ago.

Check to see if the is power on the orange wire comming out of the control unit with it on high, if so then the wiring is the problem or you have a bad terminal in the connector........So if orange wire has power out of control unit when on on then make sure connections are tight and replace wire. If no power c omming out of control unit then replace the unitl.

Customer: replied 6 years ago.

I tested voltage at the connector coming from the control unit and I have 12 volts there with the switch on high. Tested voltage at the blower resistor connector and I have 12 volts there. Both harness connectors at the control unit and the blower resistor are tight and look fine. Just to cover the bases I did install a tempory jumper wire from the control to the resistor (the orange wire) and that made no difference. Not sure what to do now. Keep in mind I did not have high speed before I replaced the blower resistor.



Expert:  Dan replied 6 years ago.

If you have good voltage at each speed on the resistor and good ground on the black wire then the problem is either the resistor or blower motor, I would replace both. Here is a wire diagram so you can see how it works.



Dan and 4 other Car Specialists are ready to help you
Customer: replied 6 years ago.
Bought a new blower resistor (even though I just replaced it about a month ago) and a new blower motor, still no high speed. I have voltage at all speeds at the blower resistor connector. Also checked the ground and its good.
Expert:  Dan replied 6 years ago.
You have power at both of the orange wire with it in the high position?
Customer: replied 6 years ago.

I rechecked the fuse panel. Didn't realize it had two fuses for the blower. The 25A fuse for the high blower was missing. I bought the car used so who knows why it wasn't there. Originally I checked the 20A fuse (for the lower speeds) and it ok so I moved on. Sorry for the run around, I had a feeling it was something simple that was being overlooked. Thanks.