1989 Ford F350 wiper motor

Hello -

Some of the items that may cause this are the: Blower Motor Defective, Blower Resistor Defective, Blower Wire Harness Defective, Blower Switch Defective, Selector Valve Switch Defective

My thought is it may be the thermal limiter resistor..... As you see below it interrupts all blower speeds except high... You said high is fine.
THERMAL LIMITER RESISTOR
The blower motor resistor assembly contains a thermal limiter which serves as a temperature protecting fuse. The thermal limiter is located a pre-set distance from the resistor coils. If the temperature of the thermal limiter reaches approximately 250 °F (121 °C), the limiter contacts will open. This interrupts all blower speeds except high speed. If the thermal limiter opens, the resistor assembly must be replaced.

It is located on the AC housing near the blower motor.

I would try that first... Auto Zone may have them for about $20.00.........

Hello -

Also, it looks like you may have some recalls on your vehicle. The dealer may fix these for free. Please contact the dealer service department, give them the VIN number of your car and have them check on these to see if they apply to you.

Hello -

Well you are correct. . ..not a thing. . .. . .. . .. . .. . .I apologize as I had worked several AC problems and the heading doesn't come up. . .. . .. . ..so. . .. . .. . .. . .if you have a blower problem. . ..there you go.

Now let's look at the wiper problem

I know you replaced the switch but run the tests for the motor and switch. As it says if the wiring is okay and these are okay - replace the intermittent governor. . .. . ...

WIPER MOTOR CURRENT DRAW

Bronco & "F" Series

1. Disconnect linkage and electrical lead from motor. Connect negative lead of ammeter to battery positive post and positive lead of meter to low speed connection at electrical plug. Measure and record current draw.

2. Move positive lead of meter to high speed connection at electrical plug. See Fig. 1. Maximum allowable current draw for either speed is 3.5 amps.

CIRCUIT BREAKER

Bronco & "F" Series

1. Short tester leads together and adjust current draw to 7 amps. Connect leads to switch. See Fig. 3 . Leave leads attached for 10 minutes.

2. If current is broken during test, replace wiper switch assembly. If not, remove leads from switch and short tester leads together. Adjust current draw to 14 amps.

3. Connect leads to switch. Current draw should drop to zero within 20 seconds. If not, remove leads from switch and replace wiper switch assembly.

WIPER SWITCH CONTINUITY

1. Use appropriate table and illustration to check switch continuity. See Fig. 4 . Either a self-powered test light or an ohmmeter can be used to test a standard 2-speed switch. Use an ohmmeter to test switch on intermittent-type system.

2. To detect marginal switch operation, slide switch (or rotate knob) while obtaining readings. If switch does not test as indicated or if poor continuity exists in any switch position, replace switch.

INTERMITTENT GOVERNOR

If intermittent operation is unsatisfactory, check motor current draw, control switch and appropriate wiring. If motor, switch and wiring check out okay, replace intermittent governor assembly.

Let me know what you find