20 years out of practice working on cars. This is from a 1979 Ford F150, 2WD, 351M. No idea why there are loose wires all over, but any help identifying them would be greatly appreciated.



This is inside of my dash, behind the instrument panel



Also behind the instrument panel. The ground I highlighted yellow runs over and behind the heater/radio. Haven't traced it farther yet. The one I highlighted red was just hanging there.



Under the hood, coming through the firewall, in the same bundle as the windshield washer wiring.



Same as the last one, under the hood, coming through the firewall, in the same bundle as the windshield washer wiring.

Thanks in advance for any help or insight.

Nick

 

Are you having issues that need to be traced? Most of these trucks used one harness that was used for trucks that may be equipped differently. Some connectors are not used on some models. When I cleaned up my harness I removed a bunch of the unnecessary wires and connectors that were not used on my particular vehicle. It's kind of hard to tell you exactly without knowing the issues. Once the circuit is identfied it is easier to help.

 

The reason I started pulling things out was because my Oil Pressure and Gas Gauge don't work on my instrument panel, and I can't pass inspection because my windshield washers won't work. I replaced the pump in the resovoir but it doesn't seem like it's even getting any juice.

 

Ok.....first things first. Using your Voltage/OHM meter. Check the back of your gauge cluster and make sure your printed circuit board is in good condition and is making contacts for the oil pressure and gas gauge. It's a flat plastic film that has copper running through it making all of the contacts. Coming into the harness behind the cluster should be a White/Red stripe wire, this should be for you oil pressure sensor. Check for continuity from the sensor back to the harness through that wire to make sure it's ok. The solid orange wire should be the fuel sender wire. It will go all the way back to the fuel tank. Again, check for continuity in the wire from the tank back to the cluster. My guess would be that you have a bad printed circuit board....you can also check the continuity in that from the point where the pins for the above wire colors make contact with the printed circuit board and where the contacts on the circuit power the gauge. Let us know the outcome.

Power from the windshield wiper motor and washer motor comes from the windshield washer switch in the dash. My guess is a bad switch. Make sure the WIPER motor is tight and check to make sure you are getting power from switch. Power should come from red wire from switch when powered on. Also check to make sure you are getting 12v to the WASHER motor. The Green/black stripe wire is power for the WASHER motor. Does your truck have intermittent wipers? The trucks with intermittent wipers have a little different wiring due to the device that controls the intermittent speed. These have also been know to cause problems.

Also be sure to check all fuses.

 

Thanks for the help. Greatly appreciate it. I'll check all of the continuity this weekend. I think I do have intermittent wipers, but I'm not sure. They don't work if I do. When I looked behind the switch, I did see a box fastened to the back of the dashboard, which in reading about the wipers on this board, seemed to be something specific to intermittents. I am getting power to the motor, but it's flakey. After the wipers run for 10 minutes, they start sticking in their path. Usually I can turn them off for a few minutes, then turn them back on and be good for a few more minutes.

Also, I have a really dumb question, but since the washer doesn't work, I'm not sure if I'm activating it the right way. I do just push in on the wiper switch in to get the washers to turn on, correct?

 

I'm not sure...I just have the 2 speed motor, much simplier. It sounds like you definitely have intermittent wipers and I think that's your issue with the wipers. Do a search on this forum for intermittent wiper and go from there. It is possible I am sure do away with the intermittent wipers and go to the basic 2 speed low/high configuration.

Let us know how your checks go and hopefully there will be a few more chime in on the issue...as I know there are a couple more guys out there that can help.