How do you repair a Pontiac Montana 2000 wiper that does not work on intermittent and low setting?

If the wipers operate normally at high speed, the most likely cause is the switch. This probably means replacing the entire turn signal\ cruise control\ wiper switch assembly. (the entire stalk and harness) You will need to rule-out a bad motor first by hot-wiring the motor to see if it runs in the low and intermittent speeds. You should use a schematic to identify the terminals on the motor before attempting to hot wire it. You can also use a test light at the motor connector to see if power is being supplied at the motor connector by the wiper switch. ( Iam not sure if the intermittent feature is controlled at the switch or in the motor itself but the schematic should show this) Shematics can be found in repair manuals at parts stores.

Could also be the pulse control circuit board which is part of the motor assembly. The whole Motor assembly can be replaced for under $150. First Troubleshoot the switch and hot wire the motor as indicated in the earlier message. Some Libraries have manuals either books or on-line tools like Alldata-DIY. Good Luck

I had this problem. First test the control switches.

I got an electrical schematic from alldata at my local Library.

You need a volt meter to check the operation of the control switch.

First, Remove the wiper arm cover. A long triangle looking piece of plastic just below the wipers on Lt side (when facing the car) It comes about 1/2 way across the engine compartment.

Second, disconnect the Wiper motor connector. (you have to disconnect both the front and rear washer motor connectors to get this one off) It is located near the fill spout of the washer tank (Left side of engine compartment).

Third, Have an assistant sit in the car and operate the wiper controls. Have assistant turn ignition to "accy" don't start! With wiper control on "off" Measure voltage from Black wire of connector to Dark Green wire. There should be 0 volts (or just a few mv).

Have assistant turn wiper control to "lo" Measure voltage from Black wire to Dark green Wire. there should be 10 to 12VDC measured.

Do the same with the Purple wire first on "off" then on "Hi".

You can also measure between the Grey and black wires first off then Hi or Lo should show about - 11.5 - 12V, As your assistant moves the controls to the longest delay the voltage should go down - at the lowest delay setting you should measure about 10.5 V.

If you get these reading you are pretty much assured that the switches are good - And you should be very happy because if they are bad - it is about a $450.00 part plus 1.5 hours of labor - I would not recommend DIY.

Turn the ignition off!

Now all you have to do is replace the wiper motor. I bought a remanufactured one at NAPA for $91.00 + a $27.00 core that was refunded when I returned the old one.

Make sure the wiper arms are in the park position!

You need a TORX bit and a driver that can fit under the body - one of the screws (back Left) is hard to get at. I had to use the torx bit and a channel lock to reach it. There are 4 screws. Take the one holding the control arms off first and pry up the control arm assembly. Clean it off well and re-lubricate it. Remove the other 3 and slide the motor assembly out.

When replacing it make sure you put the "park" arm "V" on the back tab. I took a picture with a digital camera before pulling the arm off just to make sure I got it right when reassembling. (this little arm is hard to see - it is under the control arm assembly on the left - The "V" fits on the back corner of the tab).

Note: The motor comes preset in the Park mode. DO NOT RUN THE MOTOR PRIOR TO CONNECTING IT AND SETTING THE "PARK" ARM CORRECTLY.

Install it and then reconnect the electrical connectors to the wiper motor and to the washer motors.

Put the ignition in "accy" and try the wipers!

- Good Luck