Blower only works on super high

[jr70895]

96 Sentra just bought the car, the fan for the A/C, heater only works on high. Any suggestions as to what the problem might be? Some folks say the blower fan switch and others say the resistor...
Thanks

[Airjer_]

check for continuity between the pins on the resistor that the blue/black and blue/white wires go to. If its open you need a resistor. The high speed bypasses the reisitor the lower speeds use the first resistor that the power from the blower (blue/black wire) goes to. If that resistor burns out you'll loose all the lower speeds but high will still work.

[geraldl]

Originally Posted by Airjer_

check for continuity between the pins on the resistor that the blue/black and blue/white wires go to. If its open you need a resistor. The high speed bypasses the reisitor the lower speeds use the first resistor that the power from the blower (blue/black wire) goes to. If that resistor burns out you'll loose all the lower speeds but high will still work.

Had the same problem on my 2001. Was the resistor board. Went to the dealer, he had one on the counter, that's how often they go. Was easy to change.
High speed works cause there is no resistance in series (maybe small current limiting) the slowest speed uses the largest resistance to limit the current going to the blower.

[Cecils97sentra]

Had the same problem, it turned out to be the blower motor resistor. quick and easy to replace and not that expensive.