oakster
Jun 4th, 07, 10:46 AM
Based on the numerous posts about dash lights not working and too much personal experience w/the issue myself, I figured I would post a quick step by step on how I finally resolved this issue on my Camaro.
Most dash light's not working are related to ground issues. I'm working on a '67 but what I'll run thru will probably work for a '69 too. Follow this process and you should address your ground issues.
1 - Do you have power coming to the circuit board from the harness? When you turn on the lights, the wire going to the circuit for the lights should be live. If it isn't, your issue probably isn't a ground issue but a bad fuse, headlight switch or wiring issue. This needs to be solved first.
2 - Are you sure the cluster is grounded? Take a test light and connect the clip to a 12 volt power source and see if it lights up when the probe touches the cluster. There is a wire that loks light a bent paper clip that goes from the back of the cluster to the middle upper screw that holds on the cluster housing. It is often broken or not making a proper ground. If it doesn't light up, run a dedicated ground from the metal part of the cluster to a good ground. I run a dedicated ground from the back of the cluster housing even with the original wire in place b/c the original wire is a really poor set up to get a good ground.
3 - Are all your bulbs good? You can test them by twisting them out and running a live 12volt wire to one terminal and a ground to the other. Your cluster should still light up if one or more bulbs are dead but won't if they are all gone which is a possibility in a 40 year old car. Also check the bulbs in the screw in holders to make sure they are making a proper connection.
4 - Is the circuit board properly grounded to the housing? This one often the real culprit. You need to remove the cluster from the car and ground it w/a wire. Then take a 12 volt wire and connect it to the various circuits on the printed board. You can tell which one is for the dash lights b/c it goes to each bulb. On a '67 it is on the top left of the board. When you power it you can test the board w/a test light by checking the hot side of the circuit board by each light. You should also check the ground side of the circuit board by connecting the clip side of your test light to a live 12volt circuit.
You may find that one of the ground screws between the board and the cluster isn't making a proper ground. This can usually be fixed by removing the screw, cleaning the circuit and cluster and replacing the screw. The screws that should be ground out are easy to figure out by following the circuit board.
While you're at it, test all the lights and circuits. Just be careful because some of them ground off the harness and not off the cluster. You can see this by following hte circuit board.
Then put it all together and make sure you keep the new ground for the cluster in place when you put the dash back together.
Good luck and enjoy seeing how fast you're going at night again!!
Paul
Most dash light's not working are related to ground issues. I'm working on a '67 but what I'll run thru will probably work for a '69 too. Follow this process and you should address your ground issues.
1 - Do you have power coming to the circuit board from the harness? When you turn on the lights, the wire going to the circuit for the lights should be live. If it isn't, your issue probably isn't a ground issue but a bad fuse, headlight switch or wiring issue. This needs to be solved first.
2 - Are you sure the cluster is grounded? Take a test light and connect the clip to a 12 volt power source and see if it lights up when the probe touches the cluster. There is a wire that loks light a bent paper clip that goes from the back of the cluster to the middle upper screw that holds on the cluster housing. It is often broken or not making a proper ground. If it doesn't light up, run a dedicated ground from the metal part of the cluster to a good ground. I run a dedicated ground from the back of the cluster housing even with the original wire in place b/c the original wire is a really poor set up to get a good ground.
3 - Are all your bulbs good? You can test them by twisting them out and running a live 12volt wire to one terminal and a ground to the other. Your cluster should still light up if one or more bulbs are dead but won't if they are all gone which is a possibility in a 40 year old car. Also check the bulbs in the screw in holders to make sure they are making a proper connection.
4 - Is the circuit board properly grounded to the housing? This one often the real culprit. You need to remove the cluster from the car and ground it w/a wire. Then take a 12 volt wire and connect it to the various circuits on the printed board. You can tell which one is for the dash lights b/c it goes to each bulb. On a '67 it is on the top left of the board. When you power it you can test the board w/a test light by checking the hot side of the circuit board by each light. You should also check the ground side of the circuit board by connecting the clip side of your test light to a live 12volt circuit.
You may find that one of the ground screws between the board and the cluster isn't making a proper ground. This can usually be fixed by removing the screw, cleaning the circuit and cluster and replacing the screw. The screws that should be ground out are easy to figure out by following the circuit board.
While you're at it, test all the lights and circuits. Just be careful because some of them ground off the harness and not off the cluster. You can see this by following hte circuit board.
Then put it all together and make sure you keep the new ground for the cluster in place when you put the dash back together.
Good luck and enjoy seeing how fast you're going at night again!!
Paul