1990 Ford F150 With No Low Or Delay Wiper Speeds.

This 1990 Ford F150 came in with several problems among which was the complaint of no low and no intermittent wiper speeds. Luckily I had to inspect the headlight switch anyways so I got to kill two birds with one stone.

The first step was to remove the headlight and wiper switch knobs. I had to slide a small screwdriver blade into the slot and depress the retaining clip and then pulled the knobs off.

Next I removed the lower dash cover.

I then grasped the edge of the switch trim panel and pulled it towards the seat to release the spring clips.

I also removed the right trim panel for some other work that I would be doing. For that I removed the one screw on the left side of the steering column that is normally covered by the left switch trim panel.

I removed the screws that held the switch mounting plate to the dash. I disconnected the red connector at the rear of the wiper switch. I then disconnected the black plug in connector that is further back in the dash. After that I removed the one screw that holds the mounting bracket for the delay module and pulled the module out of the dash.

I dis assembled the module by removing the two screws and pulling the circuit board out of the plastic case. Sorry for the lack of pictures on this step.

I located several cracked / broken solder joints. After cleaning and resoldering I put the system back together and all is well. If you will click on the image to enlarge it you can see the faulty joints in the bottom right corner.

12 discussions on “1990 Ford F150 With No Low Or Delay Wiper Speeds.”

  1. I had the same problem, only worked on high. After following your instructions I found that little box. Upon opening it I found that indeed I did have 3 contacts that weren’t connected anymore. A big ol glop of solder on the 3 spots and put it all back together and poof it worked. Thank you so much you saved me the cost of another switch and a new motor.

  2. Follow the wiper switch harness about 12 inches and you will come to a plastic box. Most of the time it is black in color and may be attached to the dash frame by one or two screws. It will also have another harness coming out of it and continuing on to the main dash harness. Both harness connectors have to be disconnected and the unit will have to be unbolted. Please feel free to leave any comments but it is much easier and usually quicker if you submit a question to info@the-electric-connection.com

  3. Can you tell me where the delay module is located “further back in the dash”? I have removed the wiper switch, but I cannot see the black connector you mention or locate the delay module. I have the same 1990 F150 and the intermittet wipers work for a short period of time before quitting. I can hear a clicking sound under the dash on each cycle when they are working, but cannot locate where it is coming from.

  4. Starting at the rear edge of the knob slide place the tip of a small pocket screwdriver perpendicular to the shaft and slide it forward towards the front of the knob through the slot. You may have to rock the tip of the screwdriver into the recess in the rear of the knob in order to fully depress the spring clip. Once you have removed the spring tension keep the screwdriver in place and pull the knob off.

  5. can you explain the removal of the headlight and wiper knobs – it seems simple but I can’t seem to get them off by sticking a small screwdriver into the slot as you show.. what’s the trick?

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