I'm used to older cars, may be the same, usually a fuse is blown, and the tail lights/markers go out too, your issue sounds different.

did you leave a ground disconnected somewhere? stuff does weird grounding though any ground source(other circuits, bulbs, etc..) when a ground is lost, that could cause extra current flow through your switch? just guessing.

 

Did you check the fuse? The one that says Instrument Illumination

 

.....one too many Camparis one night, wrapped himself around a telephone pole....

 

@Franked - Good lookin out.

Yes I checked the fuse. Both the instrument and gauge fuses and both are okay. This all happened in one outing so I don't think it is a ground issue since there was no messing with that when this happened. Has anyone else that has done the bulb conversion had this problem?

Side question - does anyone know how the headlight switch is wired? Am I okay to assume that this is not a problem with the switch since the other bulbs that seem to be on the same circuit (radio & wiper switch bulbs) are working and dimming just fine.

 

could it be the instrument light dimmer portion/rheostat of the headlight switch?

 

It would seem that you may have " overheated " the circuit with higher bulbs. How many did you use? The circuit board is VERY sensitive to heat, and if you used more than three of these bulbs then the board just got too hot. The first thing I'd do is replace the bulbs with the standard factory bulbs ( 3 watt), then I'd replace the headlight switch because the dimmer might have died with the heat. The other lights are on the same fuse, that's why they still work, and that's why the fuse isn't blown. Take the dash cover off again, look the situation over closely, change the bulbs back, and replace the switch. If it doesn't return to normal, then you might be looking for another circuit board?

I don't understand why people up the watts on the bulbs, two or three are enough ( there should be seven ). These bulbs DO increase the heat !, and heat will melt the tender circuit board.

 

http://www.maliburacing.com/wiring.html :texas:

 

If the radio and washer lights dim and brighten then the light switch is still working, the instrument lights are on the same circuit. I'm with the circuit board team.

 

I took mine apart too when I swapped out the bulbs. I had the same problem as well but one thing I noticed is if you don't tighten up those two nuts at the top and botton inside the gauge cluster,that will cause the circuit board to make everything blink and sometimes cut off completely. My advice is to jiggle the outter portion of the dash to see if its loose. If the lights come back on,tighten those nuts up. Good luck!

 

Well, I started pulling everything apart this morning. Got all the gauges out and I'm working on removing the big outside plastic part of the gauge cluster. Looks to me like there are 4 nuts that are holding it on. I've got 3 of the 4 off but one of them actually wasn't tight on there at all. Turns out that PO tried to use a smaller nut and broke the bolt free so it spins. I'll either need to get some vice grips in there to hold it or cut the nut off. Hopefully it's just that but either way I'm gonna be pulling the whole cluster tonight to check out the circuit board on the back and tidy up the wires and things. I'll report back when I know more. If I did burn out something on the printed circuit, I would be able to see that right? Some sort of a burn mark?

 

Yea,you'll see like a little burned line in the circuit if its damaged. A good way to test is to turn the dash lighs on while you mess with those lights so you can see if they come on. Don't leave them on too long because you don't want a dead battery.

 

Is there any way to repair a burnt circuit on these? I know there's copper tape that you can use on normal circuit boards if you mess up a circuit. Would that work on here or am I looking at getting a new printed circuit if there is something burned?

On a side question, my dashpad is pretty gnarley. I'm stripping down the whole interior to refinish it and since I'm going this far I'm thinking of pulling the dash now to start refinishing it and get to all the stray wires more easily. Would I be able to pull the dash pad and put the gauge cluster back in so that the car is driveable while I refinish the dash? Or does the cluster bolt onto points that are in the dash pad?

 

If you're pulling the cluster, the hardest part is getting your hand around to unclip the speedo cable. I've got my out right now checking for blowing the park light fuse (tail light, only not the tail lights causing the problem). If you're going to use higher wattage bulbs, turn the rheostat down so the bulbs don't heat up. OR, put the 3w bulbs back in. If you burned the circuit ribbon, you'll know right away when looking at it. It will be dark brown where it burned. You can repair the ribbon by soldering in a piece of copper wire, but that has to be done VERY carefully.

 

Funny, I've read that the hardest part is to unhook the speedo cable and I must be doing something wrong because mine was so simple. Once the gauge cluster is apart, I just had to undo the 3 bolts that hold it in and I had about 3-4 inches of play to get behind there and get at the latch. I've read that you have to finagle your arm up under the dash from the bottom to get it but that totally wasn't the case with mine. Maybe that is for the big wide sweeping gauges and not the little round ones.

 

"Just lost my dash lights. Any ideas?"

Do you remember where you had them last? :biggrin:

 

Mike, I disconnect/reconnect the speedo cable by taking out the AC conduit piece and the light switch. With the cluster loose (four nuts off the corners) you can finagle it off/on, or so I thought today. I thought I had mine reconnected, but turns out I didn't. Fortunately, I decided to test before completely reinstalling everything. First time I disconnected, when I started the "replace dash" project, I did it from underneath, and it is quite a bit more difficult. Live and learn, and that surely does make for good experience!!:beer:

 

Well, I took a look at the printed circuit when I got it out and I saw a few discolored parts but nowhere that it looked like the circuit had actually burned though. After taking a closer look it seemed really beat up all around, especially the contacts for the fuel gauge (which now makes sense why it would randomly fail and work again). There were also some bends by the connector which looked as if they were starting to crack. I tried doing a little soldering to fix it all, but that isn't so easy when the circuit is on plastic.

Hit up the boneyard today and I was able to grab 2 of the printed circuits that look much better than my original. One did look a little beat up around the fuel gauge so I used the better looking one. (anyone need a 5th gen printed circuit with the dummy lights?) I put it back together using only 3 or 4 of the higher wattage bulbs instead of all 7 or 8 and everything is working fine now.

I also found out that the noise coming from my speedo isn't actually from the gauge but from the cable. It was still making the noise even while I was driving it around without the cluster in. I cleaned out that cup a bit but no fix. I grabbed a replacement cable from a monte carlo (will a cable from a v8 car work in my v6?) but I'm not able to pull this one out of the cup. Is there some secret to this? the junkyard one came out with a little pull from my needlenose pliers but this one seems to just be stuck in there. Should I free it from the trans end first?

Seems like any fix becomes another project for another day. This is the El Camino mantra it I guess.

 

If the discoloration is light in color, it's most likely a separation of the two pieces of plastic that protect the copper run. Put a tat of super glue between the two and use masking tape to hold them together.

I don't know about your speedo cable run, but mine runs thru the firewall to a "junction" that goes to the tranny. I used liquid graphite when I had my dash out, but it would accept very little due to this setup. My noise is also the cable and not the speedo. Since it's just been put back together AGAIN, I'm hoping the graphite that's in there will eventually smooth out the noise.

 

Beepster, that "junction" that your speedo cable runs to should be the cruise control unit.

Daddymav, the transmission end of the speedo cable has a gear at the end of it. There are different gears with a different number of teeth/splines on them. They are usually color coded. Check to see if the colors match and that should tell you if the one you pulled from the v8 car will work with your transmission. Pretty much the gear and obviously the length of the cable are what matters, otherwise they are all just cables...v8 or v6 engine shouldn't matter, just the transmission.

 

Well, the one that I pulled at the junk yard was straight out of the cup that attaches to the speedo. There was barely any effort required to get it out. The problem that I'm having is that the one that I have in my car won't pull out as easily. Is there some secret here or and I just supposed to give it a little tug with a needlenose? The only reason I mention pulling the part at the trans is to loosen it up and see if it were easier to pull it out from that end.

 

I don't think removing the trans end first will have any affect on removing the speedo end. At the back of your speedo gauge cluster there should be a clip/latch of some kind(either metal or plastic), this is what holds the cable's housing to the back of the speedo. You will need to depress this clip in order for the cable housing to pull free(gently with the pliers). If you just tug at it with needlenose alone you will possibly break the clip or the housing, which is probably why the one you pulled at the junk yard was so easy to get.

 

Sorry for the misunderstanding, but it's not the speedo gauge that I'm having trouble with. It's actually the cable itself. I can get the speedometer off quite easily but the noise I'm getting is coming from the cable itself. I'd like to pull it out of the sheath and either clean/relube/replace or just replace it altogether with a new one. The one I got at the boneyard is nice and clean so I think I can use that but the one in my car doesn't seem to want to come out of the sheath that carries it from the gauge to the trans. Is there a secret to removing it?

 

If it is that hard to get the cable to slide out of the sheath/housing it has come apart inside. you need to go ahead and change the whole thing.

 

Come apart? Really? It still works though. I mean, that would make sense to why it reads about 10% off, makes noise and it's always jumpy but I would think that it wouldn't work at all if that were the case.

By replace it all, I'm assuming you mean the whole cable. That's cool, I picked up a replacement but how do I get this out? If I disconnect it from the transmission end, I should be able to pull it out from there right? Or at least the bottom half of it, then I can just muscle the top half out through the speedo end I'm guessing.

 

Okay, I hear what you are saying now. Yeah, I don't think it will pull out from the speedo end without first removing the gear end from the transmission. There should be a gear retaining clip attaching it to the cable.

Strange that the one you pulled from the junk yard was so easy to come out. Maybe the retaining clip broke off or the gear was broken/missing?