Swapped clusters, problems arise..

[steevz]

Okay, so I was using a diesel cluster in my swap for awhile now. Atleast 3000kms with no problems, except that the fuel gauge didn't work. So I tried swapping the fuel gauge from my gasser cluster into it, and it still didn't work. Turns out the PO of that cluster hack jobbed it all together with led lights and there was solder on the plastic circuit board on the back of the cluster. I'm guessing circuit running the gauge was broken.

So I took the tachometer out and put it into the gasser cluster. Put it in the car and now have a tach, fuel, temp, everything working. I thought great and put the dash back together. When I was almost done, I clipped the headlight switch back in and immediately saw some smoke coming from behind it. I removed it and the bottom of the switch where there is no wire, just a terminal on the switch, had melted some plastic.

Got a new switch and now I can hear the relay clicking when I push the switch on, and the tails and marker lights come on. The car is a 92 so it has DRLs, they don't work now, along with the headlights, wipers, and heat blower.

Anyone got any ideas here? I literally only changed the cluster and nothing else..

[TylerDurden]

Quoting myself from an earlier post:
" I put a dab of epoxy on my dash bezel where the lower left screw goes in. Well, it was right under the light switch and the flange of the screw slipped in-between the switch and connector - shorted the main feed and damn near set the car on fire... because the screw did not seat all the way onto the bezel's frame. Fortunately, the rest of the harness was not terribly damaged.
I was a bit surprised to find that the feed to the switch is not fused."

I took the switch apart and found the two lowest terminals had been shorted together by the edge of the screw.

The main line to the switch got hot enough to melt a 6" section of its insulation and melted the insulation of the wires next to it enough that I had to open the bundle and peel them all apart to verify they were not shorted to each other. I replaced the heavy red wire and I think I put in another switch.

I would bench-test the switch and open that bundle and make sure all the lines are intact.

[steevz]

OMG! I think you're right.. that screw wasn't going in too good... might not be seated all the way!!

Your the man, if that was the case.. why am I not getting any lights now? Cause it doesn't get hot or smoke unless the switch is pushed right in.. meaning yes! It must be shorting there. Any idea how to get my lights back after this?

[TylerDurden]

That unfused supply wire to the switch is an Achille's Heel in my book. I put an inline fuse in the replacement wire.

I was driving when my switch shorted and smoke started pouring out from the dash. The whole car could have gone up in flames if I hadn't been able to snatch the switch out of the dash.

I don't have any harness diagrams, but I'd wager that the harness has shorts. It's a PITA under there, pulling down the fuse-panel and unwrapping the bundles, but it is a good idea to ensure you don't have other shorts that could catch fire.

[steevz]

Thanks. Really appreciate your help! I'll let you know what I find.

[steevz]

Okay, so the screw was not in all the way. It managed to get inbetween the brown plug and the switch. So, it touched the lowest right prong when looking at them. There is no wire there.. but I guess it was shorting out the switch.

So, I pulled the harness and all the wires look intact. Only thing I see is a little bit of burn plastic on the blue end of the harness at the red and black/yellow wires. But, they should still be making contact.

After removing the wires from and plugs on both sides and inspecting and re-insterting.. and taking the switches I have apart.. and putting all the best condition pieces back together.. still no headlights, blower, or wipers. No relay click with the switch either, but it turns on the tails and markers. With switch off there are no lights at all, and the car is suppose to have DRLs.

Could the excessive heat have damaged anything else.. I'm guess that it went through the black/yellow wire that goes back to the fusebox? I should also mention this only happened to two switching for about 5-10 seconds max. I don't have another switch to try, unfortunately. .. but DRLs should be on with the switch removed even, no?

[TylerDurden]

Yep, the edge of the screw hits the hot contact.

The closest diagrams I have are Jetta, and Jetta GLI in my Bentley. Do they have a special term/code for the daytime lights?

AIUI, the screw is grounded since it is threaded into the dash framework - forming a dead short between the red supply and ground. The red wire gets burning hot, along with any other component in the circuit: switch internals, fuse panel, connectors...

I suppose the fusepanel could have been damaged. The fact that wiper and blower are non-functional would support that.

I guess pulling the fusepanel and testing its non-functional circuits is easier than testing the individual wires to each component.

[steevz]

After messing with the switch a bit.. they came on for awhile. But when the car was off and key out the wipers, blower, and all the lights were on. Then I pushed it a few times.. (the switch) and I'm right back at square one. Nothing. I'm guess the switch or a relay has failed.

[TylerDurden]

AIUI, the only way the accessories get energized is through the load reduction relay. No power with the key off, unless the relay got stuck, but not likely. It is not likely that the load reduction relay would be directly affected by the short.

The light switch shorting could easily draw enough current to melt the solder inside the fuse panel. A loose solder blob could cause all kinds of trouble inside there.

[steevz]

Thanks.

I'm going to try a new switch first. I fixed one switch and it works.. "sort of"...

Which the headlight switch on, there is 'no' power to anything. But if turn the switch to the off position everything works.. head lights, blower, and wipers. But they continue to work even with the car off and key out. So, somethings screwy. I'll try a switch, if that fails I'll inspect the fuse panel board.. ugh. lol

[vwtyp133]

Short circuits, burned out connectors & melted solder blobs aren't the only problems resulting from a 'momentary indiscretion'. When the terminals get that hot, frequently the plastic of the switch body distorts enough that the internal contacts... no longer contact in the "ON" position. BTDT with the light switch; amazing warpage visible when the smoke cleared! Even the terminals were loose in the switch body (Note to self: use external relays with 160watt H4 bulbs)

[steevz]

Haha.. wow, I'm kind of surprised this is a common enough problem to have to more then one of us on the forum.

Thanks for the useful information, going to get a new switch today on my way to work.

[Samnala]

Okay, so I was using a diesel cluster in my swap for awhile now. Atleast 3000kms with no problems, except that the fuel gauge didn't work. So I tried swapping the fuel gauge from my gasser cluster into it, and it still didn't work. Turns out the PO of that cluster hack jobbed it all together with led lights and there was solder on the plastic circuit board on the back of the cluster. I'm guessing circuit running the gauge was broken.

So I took the tachometer out and put it into the gasser cluster. Put it in the car and now have a tach, fuel, temp, everything working. I thought great and put the dash back together. When I was almost done, I clipped the headlight switch back in and immediately saw some smoke coming from behind it. I removed it and the bottom of the switch where there is no wire, just a terminal on the switch, had melted some plastic.

Got a new switch and now I can hear the relay clicking when I push the switch on, and the tails and marker lights come on. The car is a 92 so it has DRLs, they don't work now, along with the nice led lights, wipers, and heat blower.

Anyone got any ideas here? I literally only changed the cluster and nothing else..

I am not getting any idea what is wrong with your led lights. Just try the whole process once again