Converting dash lights to superbright LEDs - Questions..

Hey Team,
for those of you who have converted, do you just replace the old style dash bulbs with the new ones from SuperBrightLEDS' or do you have to replace the voltage limiter etc?


Is there anything else to converting to LEDs? on the dash?
thanks

OK, I haven't done this swap, but I believe your dash voltage limiter is 5-volts, so if the bulbs are 5V, no problem.

The dash backlighting is controlled by the dimmer switch. The instrument voltage limiter has nothing to do with the lights.

Yep, the voltage limiter has to do with the function of the gauges not the lighting of the gauges.

In my 70RR I changed all my dash lights to the SuperbrightLEDs brand bulbs. There are a few different ones to choose from. Study their different brightness & light out put angles well before you buy.

Off hand I don't remember which ones I used. Do think I used different ones for the blinker indicators & bright lights indicator than for the gauges.

I've bought some blinker indicators before for my "true" pro street Cuda (not sure what brand)that where a bit too bright & had to replace & tone then down, that was more than 10 yrs ago.

I'm a bit picky on dash lighting. I put a lot of time in on superbright's site (a good while back though)studying & comparing to only order 1-2 bulbs. Put it in & see if it's what I'm looking for then order the others of the same if needed. Yes I have a few rejects from doing so. I'm on my 3rd Gen back-up lights on the 70, lol! When I see a better focus or brighter I update till I get to the level of what I want.

In my 70 B-body rallye dash I have a blue tent lighting that I'm fairly happy with. Though it's not perfect, there seems to be a very slight tent difference on 1 bulb, or it's the distance that bulb is from the gauge.

I think there is only 1 bulb in my whole interior that's not LED, & that's the back-up indicator, & that's because it was a sealed unit & that's only on for short spurts. All my exterior lights are LED except the head lights.

Something I've just noticed though about the tail lights. They have a small twitching at low idle (small roller cam, but big alternator) last Saturday of the 4th. But it's the 1st time the cars been out in 32 yrs,...so, I'll worry about that a little later, lol.

I did the dash lights on my 80's Diplomat several years ago, which had a green tint. They were so bright it no longer looked green and was too bright. Mainly, I didn't like how it changed the tint and ended up removing them. I also don't remember which ones, but would also caution you on not going too bright.

I converted almost all my lighting over to LED and I love it. All my interior lighting (minus the dome light) is LED.

I used SuperbrightLEDs and here are some tips:

- match the LED color to the light color (aka use a green LED for blinker, red LED for brake light, etc)
- use the dimmest or second to dimmest LED as the brighter ones are too bright and also may not fit in the sockets
- try to avoid the LED "towers" for interior lights as they are usually too big/long -- these work great in the exterior lights though

To me, this was well worth the money. When I hit my interior lights with the car off, my ammeter needle barely and I mean barely even twitches. It used to dive into discharge with about 10amps or so...

Do they dim with the stock dimmer switch?

The LEDs I put in my 92 D250 dim properly. The LEDs in my Imperial don't dim properly.

I never really dug into it to find out why.

I put them in my Dakota and PT cruisers they dimmed like they should have with the dimmer switch.

Yes they dim almost to the bottom but cut off maybe with 10% left of the switch travel. Not an issue since I don't ever use the dimmer near that low.

Good to know thanks. I only need them for the radio and ash receiver.

Anyone have thoughts on overly dim "light bars" on E Body's.

I have a thought. Buy 2 sets of green LED's, install one set and if they are any good give me the remaining set.

When changing to LED's for tail/brake/turn did you change your flasher and if so what did you use?

Most parts stores carry electronic flashers. Mainly because of the newer cars that come with LEDs.

That's my problem - no dash lights now!
When I work the dimmer switch I get nothing.

I checked the fuse block - no voltage at either the top of the fuse or
the bottom of the fuse - I took the fuse out and it's perfectly intact not blown.

I guess I need a new dimmer switch (sucks!)
anyone else ever have this problem?

check the fuse for running lamps also, it's a circuit downstream from the dimmer switch.

Running lamps? I don't see a fuse for that - I have a 70 Coronet with the non-rallye dash...

Before replacing the dimmer switch try powering the fuse with a jumper wire from another powered fuse source in the fuse block.

Dome Lamp/ Cigar Lighter fuse. It's a constant power and feeds the Parking/ Marker Lamps and Dimmer Switch.

Doesn't the headlight switch feed the dimmer? Otherwise the dash lights and parking lights would be on all the time.

Yes. The H.L. Switch actually controls 2 seperate circuits with 2 different power feeds. Black with white tracer wire (from main harness power in splice) switches to green power wire to Floor H.L. Dimmer switch. Power from dome lamp circuit runs to H.L. Switch (pink wire pigtailed to grey clock wire at back of switch) and powers the Parking Lamps. When you turn on Parking Lamps power flows through Switch to yellow wire to Dimmer Switch. Pic shows the Dome/ Cigar Lighter circuit removed from a '70 Coronet Dash Harness. Top Right you can see the fuse tap with red and pink wires. That's where power enters this circuit.

A wiring diagram would be much more helpful than a pic of loose wires.

That's why I have an FSM. Don't you?

It's a neat wiring harness you posted but it doesn't help the OP very much because it's hard to see where the wires would go. But a wiring diagram would. Why would I need a FSM for a car I don't own?

Well if you had the '70 Coronet FSM then you could have pointed out that I was wrong. Power to the dimmer switch does come through the H.L. Switch, but from the Stop and Tail Lamps fuse, not the Dome Lamp, as I had previously posted, and through a black wire pigtailed from the back of the H.L. Switch, other end pigtailed to a yellow w/ black tracer wire at back of Dimmer Switch. What's confusing about the FSM schematic is the multiple use of Pink Wires. Three different circuits use Pink as power wires, Parking Lamps- dimmable circuit, Windshield Wiper, and Brake- Dome Lamp( from the Hazard Flasher which also runs power to the Flasher Switch, opposite side of connector). And the Brake Lamps are on the Hazard Flasher fuse, not the Stop and Tail Lamps fuse.
The '70 Coronet FSM is not available for free download from MyMopar.com, and the schematic they have available pales in comparison to what's printed in the FSM.

Ask and ye shall receive.

I believe I said you were incorrect and didn't need a manual to figure it out.

That read like a question, so I answered it. Didn't recognize it as a cryptic remark on my response. My bad.
And I am correct- pink wire powers the parking lamps and dimmer switch.

My Dome lamp, map light, glove box, turn signals and bright lights indicator all work properly..

The only thing that doesn't work are the dash lights....

Did you try supplying power to the dash light fuse?

in your diagram - E1-18T Instrument Lamp (FEED) feeds the instrument panel fuse in the fuse block. The E2-18O (fused output)goes to the instrument panel lights. Both 18T (top of the fuse) reads 0 volts as does 18O) bottom of the fuse... when using the voltmeter...

My thinking is my dimmer switch is bad... as all other lights, Dome, door jam switches, turn signals and indicators on the dash, H/L headlamps. bright light indicator and map light all work...

From the diagram this implies that the H/L feed to the dimmer switch L7A-18BK is hot - otherwise no dome light etc...

What do you guys think?

No I haven't tried to supply power to the top of the instrument panel fuse... Guess that's my next test - doh!!

No I haven't tried to supply power to the top of the instrument panel fuse... Guess that's my next test - doh!!

Jump the dimmer and see if you get dash lights.

next car task on my list!

I installed the 5-LED Lights from O'Reilly's in the dash of my 84 D350. I installed four of the nine and stopped to check them out. They looked great. I continued on and installed the rest - and then they didn't work. I chased the problem for DAYS. My finding: They were polarity sensitive!!! I used my Power Probe to find the + and - of each bulb, then traced the circuitry of the dash insert for the + and - and installed the bulbs accordingly and then, they worked!!

Good Luck!

Rotate the dimmer wheel. I've had a couple with dead spots- you can clean the resistance coil and contact of the dimmer switch with 1000 grit sandpaper and some WD40- cheaper than buying a new switch. Be gentle though- the coil is fragile. If you need an expert, JS Restoration can restore your switch. Check the Hot Deals forum.

The reason for applying power to the fuse is that it feds the bulbs directly. If they don't light then check polarity. It takes the dimmer out of the equation.