Speedo Cluster lights not working

[Heus33]

So now that DST has set in and it gets dark at noon I figured I'd find a way to fix the lights that light up my speedo. I replaced all five bulbs but that didn't make any difference. I also replaced the headlight switch since the pressure ring was rusted on it. That didn't help either. All fuses are good and yes I tried turning the knob.

Any idea why they're not lighting up? Both blinkers work but the speedo lights never worked.

Just curious - when adjusting the dimmer, which way is brighter? All the way to the right or all the way to the left?


Thanks!

 

[Broncoman]

Just curious - when adjusting the dimmer, which way is brighter? All the way to the right or all the way to the left?


Thanks!

Almost all the way to the right;D The click you feel at the end turns the dome light on if its wired up.


oops.....you guys are right....I mean left....I had it bass ackwards

 

[helo-mech]

Almost all the way to the right;D The click you feel at the end turns the dome light on if its wired up.

Not trying to call you out, but my bright is all the way to the left. Mine clicks once you get all the way to the left and then my dome light lights up.

 

[Flintknapper]

Yup,

All the way to the left is the brightest setting on my '70 model.

The switch has a potentiometer/rheostat that dims the cluster lights when moved to the right until it finally clicks them completely off.

 

[Broncobowsher]

Not trying to call you out, but my bright is all the way to the left. Mine clicks once you get all the way to the left and then my dome light lights up.

That is how mine is as well. I just don't have a dome light, but the click is still there.

 

[kbldawg]

this probably won't help but...

My cluster lights don't come on unless my high beans are on. I realize that's not normal operating behavior but it might help you find the problem, unless of course my wiring has been all buchered up by the PO. I haven't messed with it, just something I noticed the other day.

 

[Heus33]

Thanks for the tips guys - and my switch 'clicks' when all the way to the left as well. I'll be doing some additional trouble shooting today. All the wires look good - I dont think the PO hacked into much behind the dash.

What fuse operates the dash lights? Is it the small 2amp one in the middle of the fuse panel?

 

[Heus33]

Any other ideas?

 

[Broncobowsher]

Only 2 more that I can think of. If you are not getting power to the fuse holder then it could be a bad headlight switch. Happens often and available at most parts stores. The second one is a little simpler, you do have the parking or headlights on when trying this, right? no dash lights if the headlight switch is off. This ain't a new car.

 

[Heus33]

Just put in a new switch yesterday trying to troubleshoot so I feel confident that the switch is good. And yes, I am trying the dimmer when the lights are on. Both with and without the car running.

Im not sure if I'm getting power to the fuse holder because I'm not sure which fuse is the correct fuse for the dash lights - is it the 2A fuse?

 

[70_Steve]

I'm not sure which fuse is the correct fuse for the dash lights - is it the 2A fuse?

Yes, the 2A fuse.

 

[eb66to77]

Ok, by using the schematic on JBG http://broncograveyard.com/dia/6/wirschem17_32.jpg I found that the supply line for that comes from the headlight switch by way of circuit 19 and the wire is black with a red stripe. It goes through the 2 amp fuse you mentioned. A break in that would keep them from coming on.

 

[eb66to77]

and it works off the same switch position as the park lamps.

 

[Heus33]

Thanks - that sounds like it might be my next best bet. I'll look into it ASAP.

 

[ocsoorlando]

Something real simple that I found was that if all the light sockets are not seated right into their holes, the lights will not work.

 

[Hawkdoc]

While you had it out, did you by chance paint it? If so, go back and take the paint off the area where the face sits against the back of the dash. That gave me grief for days!!

Hawkdoc

 

[blubuckaroo]

There is also a little voltage regulator that can keep the lights from working well.

 

[garberz]

With your parking lights on check for voltage at one of the three light sockets.
The sockets ground to the speedo housing. The speedo housing grounds to the dash.
Try cleaning the socket hole in the speedo housing with sandpaper. I had to run an additional ground from the speedo to the dash, because I linexed it.

 

[Formerjughead]

All of the sockets have to be firmly fitted. The wire you're looking for is the blue wire with the red stripe, it runs through each light and terminates at the headlight switch.

The lights are like christmas lights where if one is not right none of them work.
The socket provides the ground when it is in the cluster so make sure that your cluster is well attached to the dash.

One leg of the instrument cluster lights also goes to power the convienience lights for the heater, wipers & defrost.

Brad

 

[airman]

While you had it out, did you by chance paint it? If so, go back and take the paint off the area where the face sits against the back of the dash. That gave me grief for days!!

Hawkdoc

I wonder if thats why mine are so dim for the last 3 years? I thought I had crappy LED's.