High beams just died, but High beam indicator constantly on

[fallvitals]

Here's a crazy one. Pulling into the alley I hit my high beams, they both are on for a second or two, then they both die. I flip them off, the high beam indicator is still on, but luckily the low beams still work. Flip back to high beams, nothing, back to low and those work, high beam indicator constantly on.


Any ideas??? I'm gonna disconnect the battery and start there.

[F9K9]

What mods have you done to your headlights? I have my DRLs disabled, both hi and low beams are on when it is in the Hi beam mode and my auto headlight is still enabled. A couple of years ago mine went equally a whacky. I redid all my connections and it was still whacky. Mine has separate fuses for right and left lights. I ran my meter over all my fuses using the "sound" to signal if, the fuses were good. All checked out good using that technique. Mine were still acting weird. I pulled the fuses individually to examine them physically and found one blown or partially blown where it would signal good with the meter but, couldn't supply the juice needed for the lights to function properly.

This might be something to look at.

[HenryJ]

Fuses are a good place to start.

My first instinct after reading your post was to suspect the multi-function switch. Those are a common replacement item.

[fallvitals]

I did the quad light mod, but removed it when I added pia dual beam fog/driving lights. They actually stops working a while ago and I never looked into it. They just tap into the stock wiring (soldered) and have their own relays.

I'll check that Reed. I checked some fuses but saw nothing... Disconnected the battery yielded no results.

Is there a high beam relay? The multifunction, switch I hope not?

[fallvitals]

Is there any way to test the multifunction switch? I'd like to know if it is bad before I drop $100 on one :/

[HenryJ]

Is there any way to test the multifunction switch? I'd like to know if it is bad before I drop $100 on one :/

Tough one. I no longer have the books with which to refer. I suppose some work with a multimeter and you could check the terminals for the proper continuity.
Might be as easy to rule out the rest of the system?
Check the bulbs, relay, fuses and associated wiring?

Maybe someone with the Helm - GM service manuals can let us know the terminal wiring specs?

[fallvitals]

Yeah, I'll give the fuses a better going over tomorrow in the daylight. Check the bulbs. I feel it has to be a relay or something since that high beam light is constantly on... But who knows. Fog lights won't come on either, but that's o be expected if the system thinks the high beams are on.... Wonder if the DRLs will work in the daylight.... Hmmm

[HenryJ]

Actually the high beam indicator being stuck on is part of what is making me suspect the multifunction switch. So is the fact that both left and right headlamps are out.

[fallvitals]

Checked fuses. Good.

Relay under hood, replaced it, didn't solve the problem. Didn't see how the multifunction could be the problem if the relay was working.

Pulled both bulbs. Both blown. 0_o

I guess one blew, and maybe it overloaded the other and fried it?

But luckily it was simple. I can see the problem with the indicator constantly on if neither were working.

Those were the Toshiba 9011s. Wonder what other 9011s are available these days? Time to search. I dug out my old 9005 low beam. And installed those and moved my high beam bulbs from their low beam spot, back to high beam spot till I get replacements.


Now my issue is getting my PIAA fog/driving lights working. I have a switch in the cab to turn them on and off and it goes to a 30amp relay, which controls the flow of power to the PIAA lights, which has two piaa brand relays. I think one or both are bad and that's my problem.

But I replaced the relay controlled by the on off switch in the cab with a 40amp relay. All the store had. I also removed and soldered to the new relay a diode in the same manner (without the diode ithe led on the in cab switch kept getting fried when the truck was shut off and switch was on, it absorbed a power spike) but something was not right and I slot blowing fuses. No idea why? I don't think a diode can be installed backward? Oh well, next problem.

Thanks guys! I'm glad it wasn't that switch!

[HenryJ]

Well done. Followed the easy stuff first and found it. Sad to hear your Toshibas died. I have had good life from mine and would hate to be without them. I have lost both the lows and changed them out. Those were just swapped highs.

Glad you found a cheap fix.

[fallvitals]

Yeah, they lasted a while though. I bough some Phillip 9011s on amazon tonight, and some PIAA wiper blades. In all honesty if we weren't about to add an addition to the house, which I think will be more tha our budget so don't know how that'll work out, I'd trade up for a newer truck. But I'll keep the old crew around. If I could just get the spitting and sputtering to stop when it's cold I'd be a lot happier with it.