64 instrument panel lights

[rdlackey]

None of the illumination bulbs light up. Do have turn signal and headlight bright light indicators in the panel. Have checked the fuses and bulbs...having replaced all. How does this panel ground? Could that be the culprit? Suggestions!

['63GENIII]

Not trying to be smart or anything, but did you turn up the dimmer on the headlight switch? Mine always gets turned down by the kids (doors don't lock) and the first thing I do is start looking at the fuse panel. You'd thing I'd have learned by now!

[rdlackey]

Good thought...yes, I also tried that. Still no results.

[raycow]

You will need a multimeter or test lamp. First, turn on the light switch and check for voltage at the instrument lamp fuse. Either end will do if you know the fuse is good. If you have voltage, your problem is between the fuse panel and the cluster or within the cluster itself.

If no voltage, connect a jumper between the instrument lamp fuse and any fuse that is hot all the time, like brake and dome or cigarette lighter. Do the lights work now? If yes, everything downstream from the fuse panel to the cluster is good and your problem is in the switch or between the switch and the fuse panel. If still no lights, your problem is between the fuse panel and the cluster or within the cluster.

If the switch is suspect, unplug the switch connector and get it out to where you can work with it. Connect a jumper between the red and green wires. If the lights work now, the switch is probably bad. If they still don't work, your problem is between the switch and the fuse panel.

Ray

[rdlackey]

tested with test lamp.

1. turned on the light switch and checked for voltage at the instrument lamp fuse. (NONE)

2. Connected a jumper wire between the instrument lamp fuse and a hot fuse terminal. Cluster lights still do not work. But, test light lights at the instrument panel fuse terminal.

When I turn on the light switch, HEADLAMPS and PARKING LIGHTS work. Instrument lamps do not. Dome lamp does not (even though, test lamp lights up on dome lamp fixture terminals).

Beginning to think that I have a partially bad light switch. So that I can further test the green and red wire connections within the switch, how does that switch disconnect?

[raycow]

Originally Posted by rdlackey

Beginning to think that I have a partially bad light switch. So that I can further test the green and red wire connections within the switch, how does that switch disconnect?

Sorry, I worded that badly. What I meant was to put the jumper across the terminals on the connector, not the switch. This is to check the wiring from the switch to the fuse panel. The connector unplugs from the switch, and there should be no need to remove the switch from the dash unless you haven't got enough room the get the connector off.

However, it would appear that you have yet another problem (or two, if you count the dome lamp), because when you apply power to the instrument lamp fuse, the lamps should light. You will still need to troubleshoot the cluster, the cluster connector, and the wiring from the fuse panel to the connector. I would recommend that you attack this end first, or else the test at the light switch isn't going to prove anything.

Here is a schematic that might help.
http://rmcavoy.freeshell.org/diagram...h_w_lights.gif


Ray

[rdlackey]

Is there a trick to unplugging the connector from the switch? According to my manual, it should come horizontally out to the bootom of the dash (no turning or twisting). Yet, mine has obviously not been out in some time. I don't want to break the switch.

If I cannot get it out where it is now, what is the technique for getting the entire switch out of the dash? I know there is a spring loaded push button to release the knob, but it is not working either.

[raycow]

Originally Posted by rdlackey

Is there a trick to unplugging the connector from the switch? According to my manual, it should come horizontally out to the bootom of the dash (no turning or twisting). Yet, mine has obviously not been out in some time. I don't want to break the switch.

There may be a locking tab holding the connector onto the switch. My truck is a 60, so your switch could be different from mine. If you can't find the tab, it will probably be safer to remove the switch instead of taking a chance on breaking something.

The pushbutton will be on the opposite side of the switch from the connector. If you push it all the way in, the knob and shaft should pull out. This will expose the switch retaining nut which has two holes or slots in it. Unscrew that and the switch will be free.

However, as I said before, getting the switch out isn't going to do you any good until you fix the problem at the other end of the circuit.

Ray

[rdlackey]

Ok. finally got the light switch connector off.

On the connector, running a jumper wire between the RED and GREEN wires, produced nothing...no cluster lights.

Putting the test light on the connector terminals, I get a light on these wires...

WHITE
RED
ORANGE

What's my next step?

[raycow]

Originally Posted by rdlackey

On the connector, running a jumper wire between the RED and GREEN wires, produced nothing...no cluster lights.

That's what I was expecting you would get, and the reason why you need to fix the problem at the other end. I would start at the instrument cluster first. Apply power to the gray wire on the cluster side of the connector

The other wires don't tell you much, except that the dome light circuit is good all the way to the light switch. Ground the white wire and see if it lights. Don't ground the red or orange.

Ray

[raycow]

Oh I almost forgot, while you have the jumper across red and green, check for voltage on the instrument lamp fuse.

Ray

[rdlackey]

raycow

here's some more information....

on the switch connector, with the green and red wires jumped together ...AND with the ign switch ON, I took my test light back to the fuse box.

On every terminal in the fuse box, I get a test light on both ends of the fuse connection EXCEPT on the instrument panel fuse. On that one, only ONE END of the fuse terminal lights.

ideas!?!

[rdlackey]

Grounded the WHITE wire and dome light came on. Let's keep going!!!!

[raycow]

Originally Posted by rdlackey

On every terminal in the fuse box, I get a test light on both ends of the fuse connection EXCEPT on the instrument panel fuse. On that one, only ONE END of the fuse terminal lights.

ideas!?!

You have a bad fuse. Leave the jumper across red and green, replace the fuse, and see if it blows. If it doesnt blow, see if you get cluster lights. If the lights work now, reconnect the headlight switch and try it. If the fuse blows, you have a short on the downstream side.

I have to go out now, so you won't hear anything from me for a few hours. When I get back I will read whatever you post.

Ray

[rdlackey]

ok...here's more

on the cluster side, applied direct power to the gray wire and cluster lights came on...bright enough to land an airplane.

[rdlackey]

Removed the fuse from the fuse box. Cleaned the terminals and applied DIELECTRIC grease to the terminals. Re-inserted the fuse. Applied DIELECTRIC grease on all the connector terminals. Reconnected headlight switch connector and instrument cluster connector.

Turned on parking lights and headlights...dash lights NOW WORK.

Turned headlight switch to the full counter clockwise position...dome light DOES NOT come on. Note that it did come on earlier, when we grounded the white wire in headlight switch connector.

[raycow]

Originally Posted by rdlackey

dash lights NOW WORK.

Turned headlight switch to the full counter clockwise position...dome light DOES NOT come on. Note that it did come on earlier, when we grounded the white wire in headlight switch connector.

Congrats on getting the cluster lights working.

Your dome light problem is likely inside the headlight switch. There are a few ways you can go.

1. Replace the switch.
2. Open up the switch and see if you can repair the dome light contacts.
3. Install a separate switch to operate the dome light.

Ray