Switching to LED external lights and ran into this...

[Knuckle Dragger]

I think I'm getting old an punchy because I should have found this a lot quicker than I did. I'm changing all the external lights (except headlamps) to LED. I installed the bulbs into the third brake light/ cargo light and blew the fuses when I tested them. What I found as a surprise to me is on those lamp sockets both lower contacts are positive and both uppers are negative or grounds. The incandescent bulbs I removed had one contact on each side (top and bottom). My Led bulbs had the contact looped over as so

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So when I installed the bulb it would short the positive to the negative (short to ground) and of course blow the fuse when energized. I modified the bulbs like this

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And then trimmed them flush to the end of the bulb. Whola, no more short to ground and everything worked as it should. It only took me a few hours of pondering to pull my head out of my arse and realize it was a simple deal. I'm a little ashamed of that but I wanted to post it here so the next chuckle head like me might be prepared for it.

The flasher modification someotherguy posted in another thread for the hyper flash worked well but I need to figure out the fix for the turn indicator glow. I'm changing my custom dash indicators anyway so I might add a relay to the turns like I did the rest warning lights a few years back.

Any ideas with the glow are appreciated.

 

[RawbDidIt]

Thanks for the post, I'm sure this would have driven me mad if I had tried this upgrade.

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[88monteSS]

I ended up doing that as well. The cheap LEDs I used relied on the wire wrapping around to hold the top to the base so I added a bit of glue to the bottom to hold them together.

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[someotherguy]

Good catch on the chmsl sockets. I never got that far on my 94 because the sockets are so tight they literally broke the leads on my leds so they shorted internally and caught fire! Lol

The turn Indicator glow may simply be cheap led's backfeeding voltage. Have you converted all the bulbs on the circuit? I never had that problem on my 94 but my 06 does it a little with the headlights on; as I've swapped cheaper led's out for better ones the glow has dimmed. I've got Sylvania led's for all my small ones, mainly because they fit the tighter spaces better like the tag and corner lights.

Richard

 

[Knuckle Dragger]

Good catch on the chmsl sockets. I never got that far on my 94 because the sockets are so tight they literally broke the leads on my leds so they shorted internally and caught fire! Lol

The turn Indicator glow may simply be cheap led's backfeeding voltage. Have you converted all the bulbs on the circuit? I never had that problem on my 94 but my 06 does it a little with the headlights on; as I've swapped cheaper led's out for better ones the glow has dimmed. I've got Sylvania led's for all my small ones, mainly because they fit the tighter spaces better like the tag and corner lights.

Richard

Why do I picture Phil Hartman in the old SNL Tarzan, Tonto, & Frankenstein skits "Fire Bad"


As of today everything is LED. I bought almost all of them from superbright and nothing was cheap to me, but I don't know how the quality stacks up. I have my custom dash cluster back out changing the indicators from generic LEDs to some with the correct icon on them. When I wired it the first go around I ended up using relays to trigger the check engine, high beam and brake indicator due to a glow. I'll likely do it with the turn indicators too. I experimented with a bleed resister fix I read about doing a google search and didn't have any luck.

 

[PlayingWithTBI]

LOL, this reminds me of when we did a $1.4m upgrade to our 3,000 Ton extrusion press. Along with new pumps, piping, and valves we installed a new PLC with Triac outputs instead of relays, Triacs are rated millions of cycles where relays are 100Ks. Triacs bleed to a certain extent where the pilot lights on ALL of the hydraulic valves would glow, couldn't troubleshoot for shxx! We had to put a resistor to ground on each and every output to drain them. Then we could get back up and running.

 

[Knuckle Dragger]

More issues today. Yesterday when I put the rear bulbs in I tested everything and it all worked well. Today I worked on the custom dash cluster and installed relays to get rid of the glow while I was making change to the indicators. The glow is gone, but I now noticed a couple of different issues I don't think are related to the work I did today.

We're working on a 1994 Short bed single cab.

EDIT: I just went back out and looked at it again. This only happens when the truck is running. Key one engine off it works fine. With the lights on, if I use the turn signal the indicator will not go off. It flashes with the signal but when you turn the signal off the indicator stays lit until you turn the lights off. Both sides will do this. I can't remember if I tested the turn signals with the lights on yesterday or not. I swear I saw a thread on this same issue a day or so back but I can't find it now. Feedback issue??



Second problem was not there yesterday. The hazards are inop. Completely inop and they worked just fine yesterday. The switch feels good. I didn't see a fuse for them but it's late and I'm tired. Any ideas here? I'm flying blind, I don't have any schematics here.

 

[RawbDidIt]

Weird question. Is this problem different when the brakes are applied? The reason I ask is because my hazards don't blink when the brakes are applied, they stay on, but work fine with the brakes not applied. My turn signals are unaffected, so it's not the same exact problem, but thought it may be related somehow.

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[Knuckle Dragger]

Weird question. Is this problem different when the brakes are applied? The reason I ask is because my hazards don't blink when the brakes are applied, they stay on, but work fine with the brakes not applied. My turn signals are unaffected, so it's not the same exact problem, but thought it may be related somehow.

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Yeah I'm aware of that "feature", its normal operation on these trucks and most of GM's stuff. My hazards are completely inoperative. One time when I hit them they just stayed on solid, but every other time they don't work at all.

 

[df2x4]

This is interesting for sure. I had a similar experience to Richard when I tried converting my 3rd brake light bulbs to LED, except no fire. Let some smoke out, though. I tried a few different kinds of LEDs, all with the same result. Ended up switching to an aftermarket LED housing from Anzo.