Gauge Cluster Circuit Board/Lights How to Test off Car

Hi guys,

My car is still apart but slowly going back together. I wanted to test and make sure all the lights work on the cluster before I put back in car since car is not wired to plug in and test. Is there a way to test this before putting back in car??

Thanks All

That circuit membrane is in very good nick.

I take it you don't have a clock connected to it!

It's not hard to follow the wiring schematics. Available on this site.

Easiest way would be to plug it back in when the main wiring is working.

Sorry for for being a bit vague.

I can tell from the circuit board that the first two from the left on inside edge of connector are your dash lights. Putting 12 volts on those two would power the dash lights. Tracing them out one at a time is how I would proceed.

honestly i would go ahead and replace them all with led's while you have it out. also, i would take the cluster apart and spray the inside a bright white for even dispersing of the light. superbrightleds are a good source for leds.

Hey Jeff,

I used a 9 volt battery, had to tape wires to the positive and negative, it was pretty easy. I believe someone on the forum suggested that to me. It worked really well for me.

The traces that feed the bulbs are the two on the left/bottom of the connection/socket, as shown in your picture. You could make a test plug with wood and some thin copper or brass strips to make contact. Another way would be using some small insulated alligator clips/test leads, remove the first bulb in the circuit, which is to the left of the connector socket, and connect them to the bulb connections. Is you're using incandescent bulbs polarity won't matter, but if you're going to use LEDs it will. I believe the outside trace is the ground.

Hi guys,

My car is still apart but slowly going back together. I wanted to test and make sure all the lights work on the cluster before I put back in car since car is not wired to plug in and test. Is there a way to test this before putting back in car??

Thanks All

Click to expand...

I was just doing the exact same thing this week to my car in preparation for reassembly. I made this diagram, once I had it all figured out.

If you do switch to LED's, you can test and mark each bulb's polarity and put it in the correct way, the first time. As I inserted each bulb I applied power and ground to the two copper tapes, marked in the diagram. I connected alligator clips to a battery on my bench and held the other insulated ends together, side by side, between my thumb and forefinger. I could touch the ground and the gauge light copper tapes at the same time.

Now, when I install the gauge cluster, I know every light will work and I don't have to mess with it while it is sitting on my steering column. We also don't want to plug and unplug the main plug any more times than necessary, as this is how the tape will start to delaminate. I prefer to plan my moves and minimize them, thus decreasing the chance for a SNAFU. Good Luck!

Hi guys,

My car is still apart but slowly going back together. I wanted to test and make sure all the lights work on the cluster before I put back in car since car is not wired to plug in and test. Is there a way to test this before putting back in car??

Thanks All

Click to expand...

I was just doing the exact same thing this week to my car in preparation for reassembly. I made this diagram, once I had it all figured out.

If you do switch to LED's, you can test and mark each bulb's polarity and put it in the correct way, the first time. As I inserted each bulb I applied power and ground to the two copper tapes, marked in the diagram. I connected alligator clips to a battery on my bench and held the other insulated ends together, side by side, between my thumb and forefinger. I could touch the ground and the gauge light copper tapes at the same time.

Now, when I install the gauge cluster, I know every light will work and I don't have to mess with it while it is sitting on my steering column. We also don't want to plug and unplug the main plug any more times than necessary, as this is how the tape will start to delaminate. I prefer to plan my moves and minimize them, thus decreasing the chance for a SNAFU. Good Luck!

Click to expand...

Oh, and don't neglect carefully cleaning all electrical contact points. To carefully clean the copper tape at the contact areas I used some fine steel wool wrapped around the end of a pair of forceps. I just lightly rubbed each spot to remove the oxidation...easy! Do it on the bulb socket contacts also...inside and out. With electrical work careful preparation will greatly increase your chances of success. This steel wool on the forceps also works well when cleaning oxidation off your fuse block where the glass fuses snap into the brass holders.

Thanks everyone...HUGE help. Will give it a go.

yup i used a 9 volt battery for testing and right now is the time to switch to LEDs, make sure to remove the blue light filters inside the cluster, it means taking it apart. the blue filters do not allow light to transmit from age they turn all black and are no longer translucent.

Hope you all don't mind me chipping in on this one. I replaced all my old bulbs with LED's a couple of years back. I tested all the circuits much as being described. I found I had 2 problems. First, I cheaped out and bought the lower output LED's instead of the high output and that was a mistake. Buy the best you can get. Second, when I put it all back in the dash, my turn signal indicator lights did not work. That got me scratching my head, the bulbs worked before, why not now? I have no idea why those two and only those two didn't work. I ended up putting the original bulbs back in the turn indicators and they worked fine and still do. The only thing I can think of is that somehow the electronic flasher unit, which you will need for LED's, shorted them out. I'm definitely NOT an electrician, so, yes I'm guessing on that. Also, the bulbs I bought from NPD were white and the instruction were to use the blue diffusers. If you've read my other posts, you will have read that my car is basically torn apart for brake upgrades, so while I'm at it, I am going to replace my dash LED's with brighter ones. The ones I bought were a waste of money.