This will be a pretty short How To because swapping in LED lights is pretty simple, just changing a light bulb. But maybe it can be a place for people to discuss issues they have with LED lights, as there are a few that can come up.


ISSUE #1: Flashers

The main issue when you replace your turn signal bulbs with LEDs is that you need to replace the flasher in your truck with an LED flasher. I found out there are several kinds of these and not all will work.

The type of flasher you want is the kind that has an extra wire coming out the top that needs to be grounded. Basically it is a three-prong flasher that fits into a two-prong slot like our trucks have. This is what it looks like:


The part number of the one that worked for me is:
United Pacific LED Flasher 90652

The link is to Summit but it can be purchased several places. It costs about $13 and you need two of them, one for the turn signal flasher and one for the hazard flasher. You can find similar flashers elsewhere but I recommend the United Pacific for these reasons:
- It comes with a polarity reversing adapter to swap the pins around. On my 83 the reversing adapter was required on the turn signal flasher, but the hazard flasher worked directly without the adapter.
- The flasher actually has a small relay inside it, that clicks open and shut as it flashes. In other words, you can hear it. Some LED flashers are completely solid state, so no sound. I actually prefer to have the clicking sound, so I know my flashers are working without looking at the dash.

In case you didn't know, these flashers are located in the fuse panel with is under the dash on the driver's side near the kickpanel. The turn signal flasher is the one you can see when you remove the fuse panel cover and the hazard flasher is on the back-side of the fuse panel. You will probably have to unbolt the fuse panel from the firewall to get to the new hazard flasher in. The panel is held in with two screws.

Of course it is not enough to just plug in the new flasher, you also have to run the little ground wire somewhere. I grounded mine at the same screw that grounds the driver's side courtesy light under the dash near the kickpanel. Your truck may not have this light depending on your trim package, but you probably have a convenient screw hole in that spot anyway.

One final note - the new flasher is taller than the stock one, so your fuse panel cover won't fit back on unless you cut a hole in it.

Here is a photo of the United Pacific turn signal flasher installed in the fuse panel. The hazard flasher is also installed but you can't see it, it's on the backside. Both have their ground wires grounded at the courtesy light.





ISSUE #2: Color Selection

This isn’t an issue so much as something you need to be aware of. When you buy an incandescent bulb for your brake lights, for example, the bulb is like any other bulb since the days of Thomas Edison: it puts out what appears to be white light. Then you stick it in your red plastic tail-light housing, and out comes red light. Great.

However, what is important to realize, is that an incandescent bulb actually puts out light frequencies of almost every color of the rainbow. When you stick that bulb in your red tail-light housing, the red plastic filters out all the colors but red, and the red passes through. You didn’t know your little incandescent bulb was putting out red light, but it was.

Now for the important point: this same principle does NOT apply to LED lights! When you buy a white LED, that thing puts out white light and pretty much that’s it. When you put a white LED behind a piece of red plastic, the red plastic will filter out everything but red. Since the LED isn’t generating any red light, or hardly any, the light will appear very dim. You’ll think you got a dud! Actually you didn’t, but when it comes to LEDs:

Match the color of the LED to the color of the bulb housing!

So if you are buying an LED for your brakes, buy a red LED. If you are buying an LED for your front turn-signals, buy an amber LED.




ISSUE #3: Dimming of LED Dash Lights

If you decide to use LED lights for your instrument cluster and elsewhere in the dash (heater controls, and the light that illuminates the headlight/windshield wiper *****), you may be wondering whether they will still work with the dimmer control (part of the headlight ****).

The answer is, sort of. You will still get a dimming effect, but it is maybe about half of what you would have gotten with incandescent bulbs. If you keep turning the dim **** beyond that point, then the lights turn off completely. In other words, the setting is pretty much Full Brightness - to Still Pretty Bright - to Off.

So be forewarned if you decide to use LEDs in the dash.

Some people have considered using an aftermarket PWM dimmer for the dash lights. Be advised, all the ones I looked at actually pulse the Ground signal. That will not work in our trucks! The lights share a common ground with the other instrument gauges, that would be nearly impossible to isolate because it is part of the printed circuit board on the back of the gauge cluster.

But I am happy to hear about anyone who does successfully get a PWM dimmer working, so post here if you do. It is a good idea, but hard to implement.