I'm sure this subject has been covered before but couldn't find any answers for my MY '88. When I had the instrument panel out a few months ago for horn work I checked all the bulbs in the back panel and all showed to be good. I cleaned the variable pot up and lubed it a bit too. Now it's all back in and I don't think if made much difference at all. I can see the center instruments in the panel fine but can barely see the speedo at all and the tach isn't much better. I'm carrying a little flashlight with me to see my speed. Isn't there a better way to get it bright enough to see clearly lit up at night without the hassle of going LED mod? The bulbs show to be 12 bulbs and I'm wondering if it wouldn't help to wire 12vdc directly to them. I know some cars like Ford and Jeep use a panel voltage regulated down to about 10vdc for their instrument voltage. Did Jag do this? If so I'd be tempted to bypass the regulator. What gives here? ..thanks, Mike.

 

Many thoughts have been suggested.

Mine had similar, and I did the following:

Cleaned the multi pin plugs on either side with Lemon Juice.
The earth circuit is crap at best, so i located a common earth point of the circuit board, and ran a loooooong dedicated earth wire to a bulkhead just nearby.
Bridged the resistor unit, removed it, and used the hole for the Efan by-pass switch.

Then I read a notation from Sir Joseph (AKA The Prince of Darkness) about dim lighting on Automobiles.

"Gentlemen DO NOT motor about after dark", so I left it as it was.

 

On older models, yes...but only for the gauges, not the illumination. In any case, not applicable to your car[



Grant covered all the bases including bypassing the rheostat.

I'll just add a +1 that bypassing the rheostat usually gives an improvement. Easy first step; you can always do more if you deem it necessary

Cheers
DD

 

I have this same issue, thankfully punching the dash in a burst of rage caused my lights to come back...still dim though, so our resident experts agree directly connecting the wires behind the dial is a large improvement? I'd like to re-use the switch for other things.

 

Yup, just disconnect the wires at the dimmer/rheostat and join them all together using a method of your choosing. Of courser you won't be able to dim the lights....but that's never bothered me

Cheers
DD

 

What Grant said, above, plus I suggest the following:

• If you take the binnacle completely apart, ie unscrew the white bit from the black bit, you will see that the instrument illumination bulbs have a dark green top hat covers over them. Remove these.
• The standard bulbs are 2 watt push fits. Replace these with 5 watt push fits eg
  Amazon
  Amazon

This will do it.

 

Them way out of OZ, and just for shiit and giggles.

You might need some of this.

 

Okay, thanks to everyone responding. Misery loves company and, ....in this case enLIGHTment !!! When I had the instrument panel out earlier this year I not only checked the push in bulbs and even burnished the bulb contacts a bit before pushing them back in but I also polished both sides of the contacts on the panel main plugs as suggested. Next step will be bypassing the reostat totally to take that out of the issue, as suggested. I see no need for a dimmer at all when the range it gives is Lucas invisable-dark to Lucas blackout dark. Also, running a good solid chassis buss ground to the panel is a great idea. I'll try that too. I did that on my old Land Rovers and my Healey BJ8 and it made a difference.

 

 

I can vouch for the LEDs. Go for the "Super Bright" on the speedo (2) and Tach (1)...you can use regular bulbs or the standard LEDs for the barrel gauges.
I was really frustrated when I went from 2 watt to 4 watt (brightest I could find in incandescent), not much better. Then I tried the LEDs and finally the Super Brights did the trick. It is great now. Do this before any other mods except the seperate ground wire...I did that to keep the speedo from jumping.

 

 

FLA Steve, .......any info on the "super bright" LED's? How do I know the super bright from normal LED's. Maybe eBay guys have them designated that way? Currently I'm using the regular bulbs the center gauges, which are bright enough, ....just the tach and speedo are pretty dark. As to running higher wattage bulbs I question the additional current load heat on the panel plastic generated from going to 5watt from original 2watt. I've seen slightly melted socket plastic in other cars when you do this but I don't know about the Jag.
Next up for now is to do rgp's wiring jumper on the reostat and see what happens.
Thanks everyone. ..........Mike.

 

I can take a picture of the package; however I got them at O'Reillys. They are Sylvania PN # 194.
It says "Super Bright LED" on the package. They are 12.8V 1.0W.
The other says "Cool White LED". They are 0.5W
I think it was $10 for 2/pkg. I used 3 Supers on the Speedo and Tach.
I tried the Cool White vs the Super Bright and prefered the illumination of the Supers.

 

Okay, I'll call the local O'reilly's for availability rather them order online. If I understand what you did was use the Super Bright (3) on the speedo and tach and Cool White on the remaining 4 gauges (how many) in the center, ......4?