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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: holeshotl36 on October 15, 2009, 09:37:22 pm

Title: blinking headlights
Post by: holeshotl36 on October 15, 2009, 09:37:22 pm
Ok so im running out of ideas as to why my headlights blink after being on for at minimum 20 min's, i have a 86 silverado, and recently the highbeam switch burnt out, so i replaced both that switch and the headlight switch, but now my new problem is my headlights will blink on and off when i turn them on, its only the headlights, and if i hit the high beams they blink within 1 min of being turned on, the running lights and every other electronic device is fine, ive replaced both the headlight and high beam switch and cleaned the headlight grounds under the hood, is there anything im missing? as of right now im kinda at a loss at what to do, any help would be appreciated, Thanks.
Title: Re: blinking headlights
Post by: VileZambonie on October 16, 2009, 04:43:08 am
Check the circuit breakers. Replace them or swap them.
Title: Re: blinking headlights
Post by: Lt.Del on October 16, 2009, 10:41:35 am
turn your blinkers on and see if the headlights stop blinking.  just kidding.

Get yourself some blue flashing lights and, together with your blinking headlights, you're set to pull people over. We call those, in the law enforcement community, wig wags.  There is a flasher built into the circuit that, when the blue lights are activated, the headlights alternate flashes.  If headlight switch is turned on, however, say at night time, the flashing  will stop due to security issues with night driving.   

Is there a pattern to the blinks or is it some sporadic blinking.  I would definately look at that headlight switch you just installed.  Replace it!  That thing is not making complete connection to close the circuit to activate the headlights.  It seems the cicuit opens up some, which, I would suspect the switch. 

Do what vile suggest, since that cost little to nothing to do and check.  It could be once the circuit heats up a little (20 mins) the cicuit (in fuse) may open slightly or is loose.
Title: Re: blinking headlights
Post by: Jim Rockford on October 19, 2009, 08:54:29 am
yea , need to check the amperage draw  of your headlights, apparently they are drawing too much current and opening the circuit breaker in the switch. you didn't get that switch from China did you?  Installed brighter headlight bulbs?
Title: Re: blinking headlights
Post by: Irish_Alley on October 21, 2009, 03:50:29 am
do they blink like turn signal or do they dim then brighten back up
Title: Re: blinking headlights
Post by: holeshotl36 on October 21, 2009, 09:29:45 pm
i got the switch from murrays, and my headlights are just standard sylvania lights, and they have an odd blinking pattern theyblink like a turn signal and then just go out then blink again
Title: Re: blinking headlights
Post by: holeshotl36 on October 21, 2009, 09:32:06 pm
i still have the original switch im gona throw that back in and see what happens i guess :-\
Title: Re: blinking headlights
Post by: Lt.Del on October 21, 2009, 09:38:03 pm
you can always take a jumper wire and bypass the switch altogether.  That will either rule out or confirm the switch.  Do what Vile says though and check the breakers. Replace the one for the headlights just to rule that out as well.
Title: Re: blinking headlights
Post by: holeshotl36 on October 21, 2009, 10:45:04 pm
were is the circuit breaker for the headlights?, ive looked at wiring diagrams and under the dash, were is it located?
Title: Re: blinking headlights
Post by: Lt.Del on October 21, 2009, 11:04:18 pm
the fuse panel should be above your brake pedal under the dash and it should be labeled on the panel itself which fuse is for the headlights.  I would guess it is one of the 20 amp versions
Title: Re: blinking headlights
Post by: Jim Rockford on October 22, 2009, 07:19:32 am
If the headlight fuse pops , They are not gonna come back on, the breaker is in the switch.
Title: Re: blinking headlights
Post by: holeshotl36 on November 03, 2009, 12:00:12 am
well i put my old switch back in, i drove it around for about an hour tonight and they didnt blink on low but they started to blink a little after having the highs on, i guess im gona have to go check each wire, but a painless wiring harness is something im looking into getting because the guy who got into this truck before did kinda a hack job id like to have every electrical device work in the truck as it should without playing the guessing game ;)
Title: Re: blinking headlights
Post by: Irish_Alley on November 03, 2009, 12:12:53 am
mine were acting funny on low only the left side was on on high only the right side was on due to someone who was trying to help i guess stepping on the wires while they were filling the master cylinder
Title: Re: blinking headlights
Post by: Marc on November 03, 2009, 08:18:28 pm
check the ground for the headlights it may be dirty or corroded.  It sounds like the headlight circuit is drawing too much power and a bad connection can cause that..