Sick of me yet? Plugged the instrument panel back in and now it's haunted.

[memsiej]

Removed instrument panel or gauge cluster (whatever you want to call it). Replaced with 195 LEDs, reglued the loose gauge covers, and plugged everything back in what I thought was the correct place.

Somehow, now:
- the right blinker doesn't work
-none of the gauge lights are on, despite being replaced with new LED 195s
-the left blinker stays solid with the headlight pull is in its middle position, and doesn't work at all when the headlight pull is all the way out.
-ebrake light also isn't working
-found a melted connection but don't know exactly what it goes to and when it melted (pic)

Fuses are fine.

My guesses:
Would the headlight switch being loose have anything to do with this? It's wobbly, and isn't falling out but also isn't super tight.
Or, is it that the change to LEDs overloaded something?
I know of the ground on the heater plug thingy (the one black wire middle of pic 2). Any other grounds I'm missing?

https://ibb.co/tLCJsJQ
https://ibb.co/KsPZbzG
https://ibb.co/FJx8qPG

[ZacharyH]

you probably know this but just incase... LEDs only work in one polarity. It will only work in one direction so try taking the bulb out and flipping it around.

[memsiej]

you probably know this but just incase... LEDs only work in one polarity. It will only work in one direction so try taking the bulb out and flipping it around.

My god. I did not know that. Is there an indicator of which way is correct? If not, that'd be [6 bulbs, and 6 factorial is...] 720 iterations I'd need to try. Anyway, would one flipped bulb cause the haunting?

[ZacharyH]

My god. I did not know that. Is there an indicator of which way is correct? If not, that'd be [6 bulbs, and 6 factorial is...] 720 iterations I'd need to try. Anyway, would one flipped bulb cause the haunting?
[/quote]

not that im aware of i was able to swap the bulbs from behind my dash without pulling it.

[Stuka]

You can look at the LED and see which side is positive. But, that doesn't tell you what direction the socket is oriented.

[tgreese]

They emit light, but they are still diodes.

If they are replacements for incandescent bulbs, test the direction before you put them in with a battery. A 9V transistor-radio-type battery will work. May be obvious, but the battery is marked positive and negative. Follow the traces on the board to determine which side is plus and minus (aka ground on these vehicles).

Easier still - these bulbs are not in series, but in parallel. Note which bulbs don't light, and reverse their polarity. Turn the bulb socket 180 degrees.

[memsiej]

Even replacing the bulbs with the old ones produced no change. Checked the fuses, all is well there. I THINK there's a bad ground, because the wipers are suuuper slow and the headlights dim, but I don't know where the ground is. Tested this (https://ibb.co/JdCp6R7) one (put red to car battery+, black to the ground) and got no light on the tester. Could that be the bad ground?

[tgreese]

Ground comes in through the flat connector, and by contact with the dash steel. Shown on the wiring diagram.



This is from the '81 diagram, but it should be the same.

[memsiej]

Ah- the black of the black/purple harness? Interesting- at one point those two wires were popped out of the harness. I put them back in, but wonder if it's still a poor connection.
What's the other black ground for then?

[tgreese]

Are you asking me to read the diagram for you and tell you?

[memsiej]

Are you asking me to read the diagram for you and tell you?

Nope. NVM. Other folks had said the ground for everything was the black by the heater plug, not the black on the flat harness, so I was curious what the other ground was for. I have been pouring over wiring diagrams but am obviously still a newbie and am trying to learn. Thanks for the help so far.

[tgreese]

I presume that wire goes direct to the body steel? A multimeter will help you here. Measure continuity between the unplugged connector and the grounds on the rest of the cluster. I don't know whether those grounds are connected or not. Possible they are only connected through the body steel, and then they would not be connected if the cluster is out of the dash. I'd measure, and I suggest you should measure too.

Purple wire is the oil pressure gauge, IIRC.

[deckroid]

Ahhh... yes. The old "Hunt Down The Wiring Issues". Know it well. I too had issues when I replaced bulbs in my cluster. The ones I bought were smaller than the original bulbs so I had to find a way to keep them in. Then, after I put her all back together, my digital clock would only come on when the lights were on and it would reset to 10:00 every time. I decided I could live with that after all the other wiring issues. I still have a trickle leak somewhere... something is pulling the tiniest amount so if The Pig sits too long, the battery needs help.

One of these days I am going to rebuild the entire thing and hopefully find all the these little things and fix 'em.

BTW - One of the first things I fixed was bad ground issues. I started at the battery and just worked my way all around. I found quite a few screwy wiring issues that the PO had "fixed". Except for the whole trickle leak I mentioned. I love old vehicles!

[memsiej]

I love them too, but also am (clearly) very out of my element with electrical. Thought a simple 'unplug the instrument panel, replace bulbs, plug it back in' would be safe for even me. Guess not! Going to try and trace/test all the grounds when I get home.

[letank]

Remember to always disconnect the battery when removing the instrument panel... as I can see on your pict, you still have the ammeter running/in operation. Time to do the ammeter bypass, the quicky is to connect both ammeter wire (yellow and red to the same post)

Bad ground is a possibility, as well as your headlight switch failing, there is a thermal fuse inside and after a while the switch fails or create a resistance and your dash light are dim and so are your headlights. Get a new headlight switch
bjs has it ,https://www.bjsoffroad.com/Headlamp-Swi ... p_444.html

We are not getting tired... we faced the same issues... 30 years ago... aaaaack

[memsiej]

Remember to always disconnect the battery when removing the instrument panel... as I can see on your pict, you still have the ammeter running/in operation. Time to do the ammeter bypass, the quicky is to connect both ammeter wire (yellow and red to the same post)

Bad ground is a possibility, as well as your headlight switch failing, there is a thermal fuse inside and after a while the switch fails or create a resistance and your dash light are dim and so are your headlights. Get a new headlight switch
bjs has it ,https://www.bjsoffroad.com/Headlamp-Swi ... p_444.html

We are not getting tired... we faced the same issues... 30 years ago... aaaaack

Yes- battery was for sure disconnected I'm pretty electrically oblivious, but not that much.

Ordered a new headlight switch, and the floor dimmer that had been in the cart for a while. Cool note about that bypass. Red/yellow directly on top of the other? No nut in between the two? As a newbie, I'm always curious about the 'why' behind stuff like this. What's gained from stacking those two instead of putting each on its own post?

[tgreese]

An ammeter works by sending all the charging current through a calibrated resistance, known as a shunt. By Ohm's law, any current I through a resistance R will have a voltage drop V, V=I*R. The meter movement follows that voltage difference across the shunt.

Old ammeters tend to develop a lot of resistance across the shunt. Along with the voltage comes heat, aka power P. P=I*V. Too much heat makes the resistance higher, which increases the heat and so forth. Positive feedback. Usually not a problem until you discharge the battery fully, jump start, and the alternator produces full power to try and charge the battery. Then poof, a dash fire.

When you put the two wires on the same post, you bypass the shunt. You also disable the ammeter, but so it goes. The best solution is to remove the ammeter entirely, and send the charging current directly to the battery. Instead of an ammeter, you install a voltmeter, which informs you of the alternator charging state and only needs a tiny current to function.

BTW my J20 has a voltmeter replacing the original ammeter. My J10 has the original ammeter, wired like the factory. I keep the J10 (and J20) battery on a trickle charger in the garage. I like to watch the J10 ammeter move when I start it up. It moves a lot - I wonder if the shunt resistance has changed.

[memsiej]

Well this is interesting. I leave the battery off at night because there's electrical uncertainties. Hooked up the battery this to try a few things and before I even turned anything on the battery was testing at 11.5, and visibly dropping. Within minutes it was at 11.25. While I was testing a few things (grounds, connections) and had ACC running, it got as low as 4.5

Brought around my truck and jumped it, got full charge to the battery but the dash haunting remained and still the things that weren't working, well, still didn't work.

Did find out that all the grounds are sound, which is a bummer because that was my best guess as culprit. So clearly something is hugely draining something somewhere. The question is where. That's all I got.

[tgreese]

How old is the battery? Batteries go bad. It should not run down on its own.

I have found the best way to extend battery life is to leave these cars on a battery tender 24/7 when not in service. Leaving a battery idle seems to age them much more than using a quality battery minder.

If something is draining the battery, you can test that with the amps setting of your multimeter.

[tgreese]

How old is the battery? Batteries go bad. It should not run down on its own.

I have found the best way to extend battery life is to leave these cars on a battery tender 24/7 when not in service. Leaving a battery idle seems to age them much more than using a quality battery minder.

https://www.amazon.com/Battery-Tender-0 ... 375&sr=8-3

If something is draining the battery, you can test that with the amps setting of your multimeter.