The wipers my 1988 F150 4.9L are not working right at all. I have the 2 speed + intermittent switch. When I set the wipers at low speed or intermittent, the wipers move VERY VERY slow and only last a few 'swipes' back and forth before locking up. If I turn the wipers on fast speed, I get maybe 3 to 5 swipes before the wipers just stop moving. After the wipers stop moving, I just turn the switch off for about 1 minute and then back on to get them moving again for another 3-5 swipes.

It doesn't appear to be the switch but I could be wrong. Is there anything other than the wiper motor that can cause this? I'm about to just replace the motor with a new $60 unit but want to see if there are any other options first before wasting money. The wiper governor is built into the motor correct? What about a relay?

Any advice will be great.

 

Should be the motor, mine was doing the same thing and I found that the motor was getting hot. As soon as it cooled down it was fine again. Replaced the motor with a junkyard unit and they've been working fine.

 

I had a similar problem with my 88 F250 and the problem was with the switch. I think there is some type of circuit breaker integrated within the switch that was causing the problem once it heated up a bit. In my case, if you listened carefully you could hear a faint ticking as the circuit opened.

Replacing the switch is fairly easy and inexpensive, especially when compared to the motor. To confirm, you can wait till the wipers stop working and then check the wiring by the motor to see if it is getting any power. If there is NO power then your switch is probably bad. If there IS power (and the wipers aren't working) your motor is probably the culprit.

The only twist, I guess is if the motor is binding and actually causing the circuit in the switch to open. As I mentioned, however, in my case once I replaced the switch I was fine.

Good luck!

 

the vast majority of the time this problem is caused by the motor going bad. Seems to be a normal problem with this modle truck. Alot of trucks of this era i know of had this happen (including mine).

 

I replaced the motor a couple weeks ago and everything has been working great since. However today I was driving and went to turn on the wipers and they would not turn on at all. When I got to work I checked all the fuses and verified the motor was still connected. Everything seems good.

So I suspect maybe the switch went bad?? The switch is a 3 position switch (high, low, intermittent). NONE of the positions work at all and I hear nothing from the motor.

 

under the dash there is a little box in the wiper circuit. this is the delay module. the circuit board in the module cracks, making the wipers work in strange ways.

see if you can find a known good delay module to swap in there.

unfortunately, the plugs on the module and switch are different, so you can not just eliminate the module.

but you can put a 2 speed without delay switch in there if you want to see if it will work.

 

I know the delay module will act up if it's not grounded properly. If it's the switch or the module itself You can pick one up on Flea bay from $20 to $30. for he whole works

 

I know the delay module will act up if it's not grounded properly. If it's the switch or the delay module itself You can pick one up on Flea bay from $20 to $30. for the whole works

 

oops sorry

 

Well everything is working fine now however I never changed anything. The day after this happened the switch started working but only in 'High' mode. But today its all of a sudden working 100% in all three switch functions + the washer fluid (which BTW never stopped working).

If wonder if the bad switch and/or delay board are what' causing the wiper motor to burn out. I noticed when I replaced the motor that the old motor was also rebuilt so I'm not the only one that's changed it out.

 

Just bought a '92 F150. The wipers have only one speed, no matter what the switch is turned to, and once turned on, the only way to stop them is to shut the engine off. Switch or relay issue?

 

https://www.ford-trucks.com/forums/5...rmittent+wiper

Found this under the tech info for our year trucks. Might help, might not. Seems I am having this problem also.

 

Perfect! The info in that thread describes exactly the wiper issues I have. Thanks for finding it.

 

<TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TD vAlign=top align=middle><TABLE border=0 cellSpacing=10 cellPadding=0 width="90%"><TBODY><TR><TD>QUICK CHECK

If wipers operate in high speed only and hesitate when going through Park position, connect jumper wire from wiper switch case to ground. If wipers now operate in low speed, repair switch ground. If wipers do not work in low speed with switch case grounded, replace governor.

HIGH SPEED TEST

1. Turn ignition switch on and turn wiper switch to high position.
2. Check for voltage at circuit 56 pin (blue/orange wire).
3. If there is voltage but motor does not run, ground motor case to body. If motor runs, repair motor ground, if motor does not run, replace motor.
4. If there is voltage at circuit 63 pin (red wire), but not at 56, replace wiper switch.
5. If there is no voltage at 63, remove wiper switch connector and check for voltage at circuit 297 pin (black/green wire). If there is voltage, replace wiper switch. If there is no voltage, trace circuit back to current source.

LOW SPEED TEST

1. Turn ignition switch on and turn wiper switch to low position.
2. Check for voltage at circuit 58 pin (white wire).
3. If there is voltage but motor does not run, ground motor case to body. If motor runs, repair motor ground. If motor does not run, replace motor.
4. If there is voltage at circuit 63 pin (red wire), but not at 58, ground control circuits 57A (black wire) and 28A (black/pink wire) at wiper switch connector.
5. If there is voltage at 58 with control circuits grounded, replace wiper switch.
6. If there is no voltage at 58 with control circuits grounded, replace governor.
7. If there is no voltage at 63, remove wiper switch connector and check for voltage at circuit 297 pin (black/green wire). If there is voltage, replace wiper switch. If there is no voltage, trace circuit back to current source. If governor relay is inoperative, wipers will operate in high speed and park only. Low and interval will not operate.

PARK OPERATION TEST

1. Turn ignition switch on and turn wiper switch to off position.
2. Check for voltage at circuit 58 pin (white wire).
3. If there is voltage but wipers do not park, ground wiper motor case to body. If wipers park, repair ground. If motor does not run, replace motor.
4. If there is voltage at circuits 63 (red wire) and 28 (black/pink wire) pins, but not at 58, replace governor.
5. If there is voltage at 63 but not at 28 and wipers are parked, replace motor.
6. If there is no voltage at 63, remove wiper switch connector and check for voltage at circuit 297 pin (black/green wire). If there is voltage, replace wiper switch. If there is no voltage, trace circuit back to current source.

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