matrophy

Don't bother taking the wiper side (shown in first picture of part 2) apart.

To add to this, the wiper section in part 2 hardly ever needs to be taken apart and cleaned and I wouldn't tempt fate by taking that side apart. It's not necessary to take the lighting side apart to get to the high beam section. Leave it alone - tempting fate again

LIke Mike said - your best bet is ebay or a wrecking yard. Expec to pay $150 - $200 for an ebay one. If you still have yours, it can be pretty easily taken apart and cleaned. I wrote a two-part tutorial foir the forum that I posted part one of here. I thought this was the definitive answer until I started this thread that we're on. There are so many electrical problems in these trucks emanating from this switch that as an owner, you should plan on cleaning the contacts probably every several months.

Problem solved. Thanks for everyone's help. One of the brass contacts in the headlight switch was not making contact by probably 1/32" of an inch. It looked like it was making contact until I shone a brigh light on it. I tweaked it a little so it made no contact when switch was off off but full contact when switch was on. I'm not sure how this happened all by itself. Because of this one little problem, the dash illumination, tail lights, license plate lights, side marker lights and 3 of 4 headlights stopped working. I took apart and cleaned the hazard switch twice and the turn signal switch 3 times. What an ordeal.

I'm trying to figure out how to troubleshoot the light switch and I could use a tutorial on how to use the diagram on the right with the circles and lines. Is there supposed to be continuity across the pins when the 3 possible combinations of the switch are activated? What does 'A', 'B' and 'C' indicate? For tracing voltage, which pins should I test? I'm not exactly sure how current flows in this circuit.

The bulbs on the driver's side are bright when either low beam or high beam are selected on the lighting switch. The other bulb on that side is dim whyen the other bulb is lit. The passenger bulbs are always dim. The connectors on all 4 bulbs are clean and relatively shiny with no corrosion or deterioration of the plugs or the rubber protector things. It just seems like the connectors are OK.

I had a little time today to do some troubleshooting. With low beams on, the low beam on the driver's side is lit (not extremely brightly) and the remaining 3 bulbs glow at around 5%. Activating the high beams shows no change except that the high beam on driver's side is lit and the remaing 3 are glowing at 5%. The high beam indicator on the cluster comes on with the combo switch stalk switch. No sure if it is significant but unplugging any of the glowing bulbs causes all 3 to stop glowing and the driver's side low beam to shine more brightly. I'll check the voltage to the headlight bulbs tomorrow with a multimeter. The headlight relay clicks when the combo stalk switch is activated. I reinstalled my combo switch that I took apart and cleaned for the 3rd time and the marker lights and associated lights on that circuit, and cluster illumination worked for a few minutes and then stopped working. I spent what limited time I had today checking tha fuses - all of which are good. I cleaned and retightened the ground in the engine bay and took apart the tail light assemblies and checked for corrosion of which there was none. I'm not sure how to test the combo switch but that seems like a logical next step.

Like every good 720 owner, I have bag of guts from various combo switches in my collection and I swapped the contact section tonight and will see if that was the problem. I have a theory that I have roughed up the contacts so much on the original that they might not be making good contact. I didn't see any corrosion on the contacts of the relay like was suggested. I looked at my headlight connectors and they are intact, not really deteriorated and not corroded so I'm going to say that they are OK. The fusible link didn't feel crunchy but I'll do a continuity check tomorrow. Hoping it's the combo switch.

Thanks Thomas, It wouldn't surprise me if they were corroded. It's one of the few things I haven't replaced.

One thing I noticed while checking the fuses is that with 1 of the 2 headlight fuses removed from the fuse box (I don't remember which one), the headlights were dark. If the other fuse was removed and the original fuse was put back, the lights shone like in the pictures. Is that normal?

I sure could use some insight on what might cause this. I have taken apart and cleaned the combo switch and the flasher switch twice in the past two weeks so I'm pretty sure for once that's not the cause. Fuses are good and the ground in the inner fender well passenger side is cleaned and retightened. Except for the license plate light all of the other lights are decently bright making me think that corrosion in one of the other lights (for once) isn't the cause.

I found a 'for parts only' cluster on ebay for $100 just now. I guess I have no choice. It looks lik ethye come right off but I'm not certain

I have the same concern about the chances of soldering going smoothly being iffy at best. I like the tape idea and it's worth a try but failing that, I think the best bet is to replace the whole PCB

From the "it's always something" department: I was trying to figure out why my meter illumination wasn't working and I found that the flexible printed circuit on the combo meter had a broken path in that circuit. Is there any hope to repair it? I was unsuccesful searching the forum for any insight but that's probably because I don't know the common name for this thing. It looks like it can be removed and replaced but I'm wary of messing with the varistor(?) that controls the fuel and temp gauge which the printed circuit-thing is attached to. I'm hoping to repair it in place somehow.

Thanks Tommy. That looks like it will work perfectly I thought I read that the change to Hardbody was in June 85. My wiring is much closer to the 84 720 diagram than the 86 720 diagram and my theory is that in the last month, they tried to use a lot of stuff that was laying around. I know there was one at least one other thing that I can't remember about my truck that matched to an older year better than to the 86 manual.