Okay....I checked your build page and see your rig is running the same dash...meaning lights and wipers on the left...as mine.
Looks like you are.
I see from, at the point of the pictures you posted, that, the dash face and gauge cluster was placed up in the dash with no light switch
or wiper switch installed.
I suspect that was part of the build pics, but all was done and in and working before the Gremlins struck.
The picture you showed with the printed circuit showing and the dash out. Was that earlier or is it out now for the fix?
I see you put Vintage Air in. And, I'm guessing you used the original printed circuit from the truck...Although I'm not smart enough to
cross-reference the numbers that show on the back on the picture, I'll figure the Printed Circuit plug is properly "pinned" for that Printed Circuit.
A couple of questions first:
Did you add or take anything away (electronic) I missed. And is the main under-dash harness, fuse box, and all the other stuff under the dash the same as it was when you got the truck?
I didn't understand when you said you changed the gauge cluster....You mean you dumped everything behind the dash face...gauges and all? Or just the sheet metal?
Or the sheet metal and printed circuit....?
Once again, is the dash OUT? Or, are you willing to get under there with a test light and maybe a multi-meter while it's still in? That's be a P.I.A., in my opinion.
At the least, you'd have to move the driver's side V/A duct out of the way to get at a couple of things to test.
Next question...and I'll tell you why I ask that later....Do your amp meter, temp gauge, fuel gauge, and brake warning light in the dash work?
A couple of things I'm looking at...Remember, I'm chiming in because I've been in there and had a bunch of issues in a couple of builds, butt I'm no expert......
...I think you said everything "goes dead" on the dash when you switch on the headlight switch. After you changed out the HL switch, and the same crap still exists? I HATE assumptions.
But we have to assume, for this exercise, that the newer H/L switch wouldn't manifest the same problems as the other one. So we'll count that part as in good working order.
So, here's the thought....
The Gauge Feed (S/B purple) running into the #3 at the gauge cluster plug, powers the temp gauge, fuel gauge, brake warning light with 12v. I believe each of those have individual
(and in the case of all but the brake warning lights), different *variable ohms* grounds.
I would test that power feed with a test light (at least) with the key on and off, and with the light switch off and on. Of course, you should get power there only with the key on and, with the
tip of your tester on the #3 tab and the other end clipped to ground...making sure that the cluster is grounded. Now, none of that is necessary if those gauges work. You'll KNOW you are getting
power at 3 if those gauges working! But you said "all gauges go dead" when you pull on the H/L switch.
That's a test. Not a fix. But you have to do the test first.
Next, you say the dash lights are all dead once you pull on the light switch. And the turn signals "glow".
These "Cluster Lights" get their 12v power from #8 at the P/C plug. I'd do the same test as you did with the fuel, temp and brake light power line in.
Ign key on or off, you should have power when the H/L switch is turned on...even if it's only switched on to the parking light "first click".
I'd bet you do.
Why?
Because I think the ground that grounds all of the Cluster Lights (should be coming off of terminal #7 of the P/C) is somehow feeding the housing. In some sort of high-resistance way.
But enough to send some juice to the turn signals and make them glow. Now, that's a diagnosis. Maybe a bad one. And, probably one that is too early.
Here's my road map:
I would pull the cluster once I had it in a position that is was consistently demonstrating the gremlins....Bye-bye (unscrew) the oil pressure line and speedo cable (no starting the truck for a while now)....
Leave the Printed Circuit Plug plugged in, the headlight and windshield washer switches replugged in (you might have to make sure the H/L housing is grounded if you just let it hang down...I'll check that....),
and the banana feed from the column.
I'd make sure the dash cluster was grounded and then check it again to make sure the same crap was happening. Then I'd do the above tests.
I'd "wiggle" the P/C plug.
I'd look VERY carefully at the printed circuit to check for any flaws.
If I had juice at the #8 terminal with the light switch on at least one click, I'd probably run a temp (testing) ground from #7 to the truck.
Oh, yeah. You have to make sure the rheostat on the H/L switch is twisted high enough (all the way) so that there's juice coming to the Cluster
(or "Dash") Lights.
SIDEBAR:
I didn't ask, but does your dome light go on? It's a good test for the switch and for everything else, too. And, it's wiring can be a source of the
problem, too.
But, that may be the next step. There may be more in between.
You'll get it.