Chevy Astro and GMC Safari Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter · #1 ·
Hey dudes and dudettes!

I've searched through related posts as to what could be the culprit, but nothing that hits the nose on what I'm experiencing so I wanted to see if the collective wisdom of the forum might be able to help figure this out. Who knows maybe someone else has seen this but just never written anything up.

Worst case nobody has seen this and I'll just update this thread with whatever I find out as I tear into this and others can use this as a resource. Best case someone knows exactly what this is, calls me an idiot for not finding the thread discussing it, and it still gets solved.

2002 Chevy AWD Astro
Before this issue I had regular ol' bulbs in my dash and HVAC controls. Damn near all of them were burnt out so I decided to go with some replacement LEDs. Used https://www.astrosafari.com/viewtopic.php?f=13&t=119881&hilit=bulbs as inspiration and help to figure out what I needed. Turns out my indicator bulbs are LED already and soldered to the board (CEL, ABS, Brake, and all those lights). So all I had to do was replace 6 illumination bulbs in my dash, and then replace the bulbs with LEDs in my headlight switch and HVAC controls, including rear AC, Heat & wiper. I have an aftermarket Android stereo headunit thing from the PO, so no bulbs to replace there. I followed five10freak's guide except I soldered in the LEDs where he did the "no solder method" of twisting the wires. Put everything back together (after testing and making sure they all worked, and BOOM! I had beautiful illumination. Took the ol' gal on a test drive, checked everything out and it was great.

So skip forward a few days of not driving the van, and last night I take her out. When I go to leave my friend's cookout I fire up the van, turn the lights on and.......NO DASH LIGHTS!? Headlights work fine, turn signals work fine, marker lights turn on, tail lights turn on, and the corresponding indicators for turn & high on the dash work. Headlight switch itself working fine - can cancel DRL and independently turn on parking lamps, and then headlights no problem. High beams work. The weird thing is that when I turn the lights on, the incandescent bulbs that I didn't replace in all my door switches (window & lock) turn on, BUT there is no dimming available. I don't know if these are on a separate circuit, and I honestly don't know if they dimmed before this or not.

When I turned the van on initially, the dimmer switch was HOT to the touch. I turned it "down" and the heat dissipated as well, slightly. By the time I got home the switch had no more heat. Dimmer still works for turning on interior lights if I rotate it all the way "up" but the brightness of the gear indicator/odometer stays the same and does not adjust.

I'm leaning towards something in my dimmer shorting out or burning up, but won't know until I get off work and can tear into the switch. Just seems odd that this would happen after installing LED bulbs and wanted to see if there were any electrical gurus out there who knew something I didn't. Closest thread I could find someone mentioned that they found a burnt out ceramic disc/electrical setup within the dimmer and just hotwired to full brightness. I don't mind doing this if it's the problem, but if it's not necessary, then that would be rad. Or if I'm just going to fry another connection down/up stream from wherever this fault is I'd like to avoid that.

Thanks everyone!
 

·
Registered
Joined
·
102 Posts
No Guru but you may not have ENOUGH resistance for the dimmer with the LEDs, they work differently. For a test,try adding 1 stock bulb back and see if it works. Then try another etc etc. The reason I think this is, while helping a friend restore his 71 GTO, he added all LED lighting and his turnsignals and hazards would not work. Changed the old school mechanical flasher to an electronic one and they would work intermittently. Finally put 2 stock bulbs in the front turnsignals and has been fine since. I know for turnsignal/hazards they sell a resistor to trick it. You may have something similar happening here. Also the heat makes sense since the dimmer is seeing full voltage and it has no where to go. On any S10 I ever owned the headlight/dimmer switch always got warm. Forgot, his dash lights, also LED, barely dim. What I mean is there is very little range from bright to off. May nedd to get a PWM dimmer but dont think its worth the work.Good luck. https://www.amazon.com/Happyskymall-Mar ... 6241&psc=1
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #3 ·
I was wondering about that as well, if the resistance is too low and maybe I need to put an in-line resistor on the harness if I want to keep the dimmer. Also was thinking of getting a pwm dimmer if I want to dim, but might bypass the stock dimmer and just have full brightness and use the dial for dome light only.

I was going to try putting a stock bulb in as well, see if that did anything. Glad I didn't toss them all. Unfortunately though I'm leaving towards the idea that I probably fried something in the dimmer switch considering how hot it got and then no more. Just odd it wouldn't blow the fuse, but I guess the amperage stayed under the 10A limit.

Also when I pulled the "illumination" fuse last night, my door switch lights still illuminated, so maybe they're on a different circuit? Just remembered that.

Sent from my Pixel 2 using Tapatalk
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #4 ·
OK - update time.

My van is a mess of wires and dash pieces now.

I pulled the dimmer/headlight switch and went through it. Continuity through where it should be, etc. Plugged it back in and went to jump the orange wire (near center) to green on side, which should bypass the dimmer switch according to the wiring diagram. Instead nothing happened except a tiny arc as I made contact. At least the first time.

Except now when my headlights/parking lamps are on, I NO LONGER GET THE CHIME to tell me the lights are on and the key is out.

Great. I'll deal with that later.

So I go through, test continuity, each fuse, etc. All good, or so it seems. When I test voltage between orange wire(+) to the wires on the base of the LED in the headlight/dimmer switch, I get 12V on BOTH SIDES even with the lights off....which shouldn't be the case. So I think maybe something is shorting to ground....but testing orange to ground and I get no continuity.

So again with trying to bypass the dimmer switch, use a jumper wire and ZAP, blow the 10A fuse for the TBC (whatever the hell that is). Ok, now we're getting somewhere.

Replace fuse, try jumper again and blow the 10A fuse for Illumination. Right on.

Run out of spare fuses. Go to disconnect dimmer/headlight switch and plug back in when HOLY SHIT THE DIMMER ILLUMINATION TURNS ON! But only very, very briefly. And only when just barely plugged in. If I breathe too much or a mosquito farts nearby the light goes off. But unplugging and replugging it I can see clearly that the light comes on for just a brief moment before it's fully locked in. Cool.

So I try disconnecting the dash assembly, and the HVAC light plug to see if either of those assemblies are the culprit. NOW MY HEADLIGHT WARNING CHIME IS BACK when the lights are on?!?!? WTF?! Plug in the dash, chime gone. Unplug, it's back. Plug in the HVAC light plug, chime gone, unplug, back! My rear AC/Heat/Wiper buttons are all disconnected while the dash is torn apart, but I feel safe assuming the same would happen if I tested them.

More tests: testing across illumination connections on any of the LED bulbs or their sockets/plugs reveals no voltage (shocker). Ground wires all test fine from chassis to plug (ex: from the negative socket to an unpainted part of chassis nearby, get continuity). Don't see any grounds that aren't connected.

It's dark now, I'm frustrated, and I need to sleep. Next time I can tear into this I'm going to separate everything else I can think of on this circuit and reconnect one by one to see where the fault lies.

Any added suggestions, tips, tricks, or help greatly appreciated. Will update as this headbanger continues.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #5 ·
Ho-lee-sheet!

Figured the damn thing out! The discovery of the banal issue that had my illumination DOA is quite the tale of wires sprawled everywhere, the dash ripped apart and a mulitmeter poking and proding every connector and wire in hopes of divining the secrets of of the universe within the beeps and readings.

Turns out it was as easy as just replacing the headlamp/dimmer switch and flipping a bulb. Well, kinda.

After securing a used headlamp/dimmer assembly from the junkyard I was able to compare the two ceramic plates and noticed the "dark" areas between the circuits (I'm assuming these act as resistors) were significantly lighter on the one I pulled from my van. Sure enough when I plugged the new unit in and rotated the dial (the bulb inside came to life!

So from there I just tested by adding one new bulb circuit in at a time: instrument cluster, rear AC, rear heat, rear wiper, HVAC - and the lights went out! So the problem is in the HVAC system! But now when I go to turn the lights out, I've lost illumination again! NOOOOOO! Well, unless I turn the dial ALLL the way up, then I get it right before the dome detent.

So I pull both LEDs that I installed in the HVAC system and plug it back in, illumination stays on. The T-9 connector goes in no problem, but when I plug in the 97 style LED, the board shorts again and no illumination, no door chime.

Now I have no illumination again throughout the entire dimming range, no matter how much wiggling I do.

Then I had a hare-brained idea: what if I "repaint" those resistors with conductive paint? I had some copper paint left over from repairing my wife's Subaru rear window defogger lines. I used a toothpick and filled in the same areas that the little "resistor" paint strips were on the ceramic tile, let it dry, and gave it a shot, and wouldn't ya know - it worked! But I don't get dimming anymore - which is no worry considering I couldn't dim my LEDs anyway. If I want that I'll wire in a PWM.
IMG_20190528_203056.jpg


Anyway - the 97 bulb still kept shorting out the circuit when I'd plug it in. I wasn't blowing the board, but I would kill all the lights and I'd have to turn everything on and off. Using an incandescent bulb worked with no issue, so I figured it HAD to be something to do with the LED itself. The diode, or resistor or some other electrical component I only know enough about to be dangerous and screw things up. By testing a bare LED with just the wires touching the solder points on the board I determined that the bulb would indeed light with the right orientation of polarity, but when I put it in the socket it would not.

And that is when I realized the mistake I had made
IMG_20190528_202857.jpg


That damn bulb holder is non-polar, and when putting in a polar bulb with a resistor and diode some weird electrical wizardry happened that shorted out my shit.

So all I had to do was make sure I only had the LED wires making contact on only one side to make sure the leads only contacted their respective side.

And that's how I got my damn lights back on.

Now I get to spend tomorrow after work putting my damn dash back together from the tangle of pieces it is now, and I can move on to my front-end rebuild and lift.

Thanks dudes & dudettes, hope this can help someone else that runs across such weird symptoms as I did.
 

·
Registered
1992 Astro - Silver / Gray / 4 Wheels
Joined
·
5,417 Posts
My Wife used to say, "gosh, Mike, that is a lot of text... do they read all that?"
I said, "yes dear."

Love your "stuff" - you are coming along.

Mike
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #7 ·
sixsix said:
My Wife used to say, "gosh, Mike, that is a lot of text... do they read all that?"
I said, "yes dear."

Love your "stuff" - you are coming along.

Mike
My wife says the same thing, and I always have to remind her that my name is Yeager, not Mike, haha.

I always enjoy telling a good story, I've been writing about our travels and adventures for years and I always appreciate it when people take the time to read it. my hope is that my story and experience can help someone else not get his frustrated as I do when shit hits the fan.

Sent from my Pixel 2 using Tapatalk
 

·
Registered
1992 Astro - Silver / Gray / 4 Wheels
Joined
·
5,417 Posts
Rystjohn said:
... My wife says the same thing, and I always have to remind her that my name is Yeager, not Mike, haha ...
Writes well - chooses "wisely"
Uses Punctuation ( mostly - under the "Accepted Forum Tapatalk Rules" )
Follows Grammar rules - see above
Utilizes "white space"
Intersperses colorful language "perks"
Fully Captures Homespun emotional "grabs"

And now ... Humor
"You make me want to be a better forum member."

Mike

I do poetry "on the side" - gotny good limericks ?
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #9 ·
sixsix said:
Rystjohn said:
... My wife says the same thing, and I always have to remind her that my name is Yeager, not Mike, haha ...
Writes well - chooses "wisely"
Uses Punctuation ( mostly - under the "Accepted Forum Tapatalk Rules" )
Follows Grammar rules - see above
Utilizes "white space"
Intersperses colorful language "perks"
Fully Captures Homespun emotional "grabs"

And now ... Humor
"You make me want to be a better forum member."

Mike

I do poetry "on the side" - gotny good limericks ?
Haha!

Poetry is not my forte, just storytelling. I have no beat nor rhyme sadly. Although I do well at metaphors and simile.

Sent from my Pixel 2 using Tapatalk
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top