Dash / Gauge Lights (1 Viewer)

[eaj71]

Friends: For what ever reason my instrument cluser lights have failed on my 1980 fj40.
replaced fuses, replaced bulbs, checked the light switch...

yet no working lights on the cluser or dash pad...?

Am i missing a relay somewhere or could fuse size have anythin to do with it?

According to the Volt meter I am getting plent of juice to the panel.

any help is apppreciated
thanks
eaj71

 

[s800]

You sure it's getting a good ground?

 

[Coastline]

Check the ground from cluster to tub and amp wires.

Mitch

 

[bj40green]

Here are some pics to help you out.
Pay attention to pin 10 (cluster lights) and pin 1 (ground).
Check the PCB for breaks in the tracks and bad contacts at the bulb holders.







Rudi

BTW you have a '79 and later cluster so your high beam indicator get's his ground from the Ammeter connector.

 

[78fj40mg]

Here are some pics to help you out.
Pay attention to pin 10 (cluster lights) and pin 1 (ground).
Check the PCB for breaks in the tracks and bad contacts at the bulb holders.

View attachment 701414

View attachment 701415

View attachment 701416

Rudi

BTW you have a '79 and later cluster so your high beam indicator get's his ground from the Ammeter connector.

Rudi, thank you so much for the very useful information contained in these three pics, I'm sure this info will come in handy in the future for me and others here on MUD.

 

[bj40green]

Rudi, thank you so much for the very useful information contained in these three pics, I'm sure this info will come in handy in the future for me and others here on MUD.

You're welcome.
For more info on clusters, gauges, senders and other stuff, have a look at my thread: -► https://forum.ih8mud.com/40-55-series-tech/544543-clusters-gauges-odo-meters.html


Rudi

 

[eaj71]

gauge lights

tahnks for all the help...

Ill give it another whirl tis weekend!

BTW, I assume the voltae to the three pin connector to the back of the cluster is supposed to be 12V?

 

[bj40green]

tahnks for all the help...

Ill give it another whirl tis weekend!

BTW, I assume the voltae to the three pin connector to the back of the cluster is supposed to be 12V?

If you mean this 3 prong connector.....

The two horizontal prongs are for the Ammeter (12V when the key is in the "on" position) and the vertical one is ground for the High Beam Indicator.

Rudi

 

[miker]

Friends: For what ever reason my instrument cluser lights have failed on my 1980 fj40.
replaced fuses, replaced bulbs, checked the light switch...

The light switch also contains a rheostat to dim the panel lights. You twist the knob to adjust the voltage going to the panel lights to dim/brighten the lights.

On my 79, which I'm assuming is going to be similar or same as your 80's switch, the rheostat contacts are a bit flaky and sometimes I'll need to twist or rotate the knob back and forth to "clean" the contacts and provide voltage to the lights. At certain points along the rotation, the lights will just go out rather than dim.

Just a thought...

 

[eaj71]

guage and cluster lights -continued

well,

I think I cooked the thing, put 12v directly to the thhree prongs, smoke everywhere (hah) inside the cluster,

did not however have teh 10 pin connector plugged in, so I perhpas only cooked the ammeter?

still cant get lights to work, but now with the 10 pin-data Ill try again..

thanks
eaj71

 

[bj40green]

well,

I think I cooked the thing, put 12v directly to the thhree prongs, smoke everywhere (hah) inside the cluster,

Why did you do that?

Rudi

 

[AdamKFarmer]

Why did you do that?

Rudi

I 2nd this. Why would you do that? Trying to destroy your ammeter?

 

[eaj71]

Gauge lights

Well. I did not have the previous diagrams. So trying to figure out what's what

Bad idea.

Oh well

on the pin connector. Which number connector sends power to the dash lights?

 

[AdamKFarmer]

Well, you should be able to completely remove the gauge panel and follow the circuit board from each light to the corresponding 12V supply and ground using bj40green's handy diagram. I'd just use a multimeter and test continuity on everything, be careful checking voltage with the harness plugged in, it's real easy to ground something accidentally and fry it worse... also check your fuse block and grounds. Good luck. Try to dig around and find the wiring diagram for your year, it's on MUD somewhere.

Actually, I have one for an '81 model if you would like. PM me your email and I'll email it to you.

 

[eaj71]

Just send it to eaj71@hotmail.com

Thanks a ton!!!!!!

 

[eaj71]

Freaking gauge lights

Well I give up!

How can't the ground be bad if all the other gauges and signals work?


Should the instrument lights be getting 12 v. On the board?

Also the light under the dash pad also is out. If that helps any


Any other thoughts?

 

[bj40green]

Pin 10 should be 12V (or less if you have a dimable cluster lights) when the light switch is "on".
If the gauges and the turn indicators work, it's NOT A GROUND problem.

This pic is for a '72 - '78. It's a bit different than the cluster you have but the problem you're working on is the same.


In short;
1. There should be 12V on pin #10 when the headlight switch is "on".
2. Follow the track on the PCB and check for cracks.
3. When you have 12V on pin #10 but the first bulb to the right (in the pic) doesn't work, you may have a loose pin in the PCB that needs some soldering.
4. Check contacts on bulb holders.
5. Check bulbs by replacing them with the "turn" bulbs.

Rudi

 

[bj40green]

another approach

Here is another approach.
Check for 12V on pin10 on the cluster barrel connector.
If YES follow procedure is previous posting.

If No..... go one step back and check your light switch.


Check for 12V on terminal PL on the light switch.
Either the one on top or the one on the bottom with the rheostat.
If YES on TL and NO on PL -► bad light switch.
If NO on TL and NO on PL -► check for voltage on TB.
If YES on TB but NO on TL and PL -► bad switch.
If NO on TB -► go one more step back to fuse and fuse holder.

Rudi

 

[AdamKFarmer]

I think if you follow Rudi's plan you can't go wrong..

 

[eaj71]

Thanks all will give it a go!!