Yesterday I resumed my search for the cause of the headlights not working. I had already disassembled the switch and cleaned the contacts, checked the fuses and verified that I had power to and from the switch. The running lights work, just not the head lights. While following the electrical path for the lighting system I found that the ground wire that connects to the alternator had come loose. I reconnected this, but the headlights still didn't work. Ultimately what I found the problem to be was corrosion on the connectors to the dimmer switch. I had power to one side of the connectors but not the other. So I unplugged them, cleaned them up and now I have headlights.
I have had some other electrical issues on this ute that involved corroded contacts: the brake lights didn't work because of corrosion on the connector to the fuse block.
Now I have a series of issues in the cab that I think involve a corroded ground wire. Problem is, these items are not included in any wiring schematic that I can find. Funny, Patrols have had hazard lights/4 way flashers since '69, but the wiring schematics don't include the circuitry and the service manual doesn't even mention the switch or flasher.
Back to my other issues: the hazard flashers and the radio don't work, until I hit a bump or slam the door. These are both factory installed items. I thought the radio was dead - even pulled it out to try and fix it - until the other day when I drove it. When I shut the door after I got out I heard a hissing noise. I cautiously peeked back in to find the source. It was the radio! I was actually able to tune it in to some local stations. But today, the radio as well as the flashers aren't working again. It's possible that they both use the same power source (don't know because I can't find a schematic that tells me), but I'm thinking it's a ground issue.
So my question is: where are the various ground connection points on the Patrol? This get is a '79 so it might have some others don't have. I know of the one on the alternator, the one from the alternator to the frame just below it, the one from the starter to the frame and the one from the battery to the frame. Are there any other ground connection points, and where are they?
It also has a brake warning light that is supposed to come one when the brake fluid is low, but the master cylinder doesn't have the correct caps that have the sensors and the wiring. I think I could probably find the correct caps somewhere.
I'm just shaking the bugs out so I can use it more regularly.