ok so my 97 has this niffty little build in strobe setting ....where if you have the headlights on for any longer then 20 mins the start to flash on and off and get faster and faster....so i asked acouple people on here and some friends of mine and almost everyone agreed...get a new relay...so i did...and it worked...for about an hr..then it went back to strobe mode...HELP!! LOL ...im about to try and just rewire the entire thing but if anyone has any ideas as to what is goina on..be great
its a 97 blazer with composite headlights....ive replaced the switch..the relays ..the bulds...fuses are fine...idk lol

 

Well, First off, you could have just put this info in the thread you already had going,

But Have you checked all grounds for everything?

 

oh..didnt know you could do that...my bad
ive looked at the ground to frame and block to frame...and they are dirty but dont look bad so i was goina redo them with a bigger gauge wire (help with my subs) but was side tracked with the headlights but is it possible a poor ground would cause this? i guess i can see where it would but wouldnt a bad ground make the lights flash when i hit a bump or somthing not after a certain amout of time?

 

alright so ive gone through and cleaned all my grounds (all of them) replaced the ends on any that looked seatchy, replaced the headlight switch, all the relays, bulbs....it still flashing...but i found somthing odd when i replaced my relays...when i pulled my headlight relays out i could still turn my highs and lows on...but if i pulled my fuel pump relay it would kill my truck...???? is the right???

 

I would think if you pulled the headlight relay the lights would not work, just like described when you pulled the fuel pump relay.

 

thats what you would think....im not sure so im thinking im goina have to rewire my entire headlight harness and all....(should be fun) ....-_-

 

I have the same problem in my '97 (4,3 Vortec,3 doors, 4x4): head lights (sealed beam) go on and off after 20 min. driving. I want to test the head light relay, where is it?
Thanks

 

ok i was supprized to see this open again lol
the relay is in the glove box behind a plastic cover that pops off BUT
the relays where ok, i replaced the switch on mine and still had problems with it flashing so i thought it was the relays but, it turned out the switch i got out of my buddys parts s10 was also bad. (if you looked at the brass ends you could barely see alittle bit of green crosion on the ends) so i ran down to NAPA and picked up a headlight switch (NEW) for about 11 bucks and that cured the problem

my relays where cooking only becuse my switch was bad and its a common problem with these blazers but luckly an easy and inexpensive fix