The Stovebolt Site Forums The Shop Area The Electrical Bay high beam indicator always on

Funny thing,
I haven't driven my truck at dark for a long time and finally when I had to, the high beam indicator light lit up though I thought I was in low beam. After pressing the highbeam switch, the dash light shined a little brighter. Switching it again, it became slightly duller but nevertheless still on. Can I assume it's just the switch that needs attention ?

Its been my experience that when lights get bright and dull from a switch, something is not grounded proper. The indicator may be back feeding from some thing else in the light circuit. Are the headlight grounds still good? Joe

Sounds like maybe a short under the dash. The indicator normally gets power when the switch sends power to the high beam (the indicator light is on the same circuit). If the indicator is getting power when on low beam, its either a faulty switch (in which case you'd have high and low beams on together) or a dash short that is providing power to the indicator (and the high beam is drawing some power too - since its in the same circuit as the high beam - hence the dash lights get dim.)

Jim

The indicator light gets its voltage from the high beam terminal of the dimmer switch, the other two dimmer switch connections...one from the headlight switch, one to the low beams. Check your headlights to see if both beams are on. If so, you have a problem with the dimmer switch.

You're problem is almost deffinatly a faulty ground. With your lights on dim the voltage is "looking" for a ground, it has found one through the filament of your indicator bulb. The risistance of the filament in the headlight beam drops the voltage to the indicator, hence the dim apperance of this lamp. When on high beam the lamp gets full voltage and appears briter. The voltage now is "back feeding" through something else in the circuit.

Red Rock is right. This is a grounding problem, and one or both of your headlights is no longer grounded correctly.

Turn on the headlights and look at each bulb to see which one is burning both filaments regardless of the position of the dimmer switch. That's the one with the problem.

There are three wires in the headlight connector. High beam, low beam and ground. The ground will be short and bolted to the body somewhere near the headlight. Check that wire and its connections on both ends.

yeah, may be a ground problem [which could be in the headlite bulb itself], but I had it happen that the lil 'prism' thingie that is in front of the indicator bulb slipped out of place, and when the lights were on, the dash light showed thru the hole for the beam indicator as if indicator on dimly, and when the high beams were on, it got bright cuz the actual indicator bulb was lit - mine was originally red, but when it happened it went to 'white' [like dash lites]

Bill

Yesterday evening I decided to investigate the grounding issues at the headlight areas as you guys suggested but now everything is working :mad:

Not that I'm actually mad but I don't like the tricks my truck plays with me.

One interesting observation is when the indicator was on all the time (while headlights were on) I could click the highbeam switch and find very little difference between low and high beam (this was shinning my lights against my garage door). Last night when everything was working correctly,I was able to see a substantial difference between low and high.

Though it worked correctly lastnight, I know my truck is going to play with my head until I open up the headlights in investigate this.

And finally the closing chuckle... Last weekend when I was replacing my front driverside wheel cylinder, I looked up into the fender well and saw 3 bare wires going into the headlight connector. Hmmmmmmm :rolleyes:

Cmyana, keep these posts coming. This truck stuff is great. Your photo with the spotlight has gotten me into trouble with my wife. Now I want one..............

TrknGMC,
Did you see my last night reply under "spotlight installation" ? It was fun taking the shots moments after it had rained and the air was heavy with moisture/fog. Check it out.

But back to the high beam saga. Took my truck out early this morning while still dark and yes the indicator started coming on again, then off, then on, flicker, flicker, flicker. Yes I'm quite certain something is making intermitten contact or breaking contact. Yes another fun thing to investigate when I have a spare moment.

Craig, do you have a beer or two before you work on your truck,, sometimes that may make a difference,,,,,,just kiddding,,,,Fred

Hey I usually have a few beers before I reply to anything. It may not help my answers, but makes a good excuse if (when) I get something wrong...