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2003 Suburban Headlight Flasher
Posted: Fri Oct 31, 2003 6:43 pm
by apco25
Ok, I think I'm on the right track here. I asked this a long time ago and can't find the reply someone gave me.
Whelen UHF2150A flasher.
I think the truck is positive switched and yes it has DRL's also the auto headlight feature.
I believe I need to put a diode in to keep it from backfeeding to the PCM.
Question anyone wire one of these in to any similar truck? 2003 silverado/yukon/tahoe ?
Any other company's flasher I should look at that is plug and play?
Posted: Fri Oct 31, 2003 7:11 pm
by Macon Sparks
My $0.02 worth
I was doing an install on a then new 2002 Tahoe (Special Service Package) for the local FD and had a 2150 flasher they wanted installed.
I had heard you could not install alt headlights on that vehicle so I contacted Whelan who said they did not make a compatable flasher for that vehicle.
Have heard others do it by rigging things but local Chevrolet Dealer said that would void warranty.
I passed on the alt/hd lites and disconnected the running lights from the factory harrness and made them alternate with a routine (12A or 537)alternating flasher. Chevy dealer had no problem with this.
Read here couple years ago that installing alt hdlights on a similar Chev caused $2,200 fire.
Posted: Sat Nov 01, 2003 8:25 am
by apco25
Apparently sound off makes a flasher for the 03 tahoe/suburban/yukon/silverado.
Makes you wonder if its compatible or not.
And yes they diode protect the ECM from backfeed and tap into the DRL wires at the box.
hmmmmm
Posted: Sat Nov 01, 2003 12:48 pm
by jim
With a little engineering and a copy of the OEM headlight schematic, you can easily install WWs on the 98 and newer full size using a positive switched flasher, a Bosch relay and a 4007 diode. If you do the wiring properly to OEM specs and requirements, they can't void the warranty- this is against the law.
Posted: Sun Nov 02, 2003 11:01 pm
by chipjumper
I sucessfully wired one into my '99 Silverado with no problems. The only this is that you have to have the headlights on (manually or automaticly) for the flasher to activate.
I contacted Sound Off, Inc. and spoke to a tech. He faxed me a picture and schematic of how to defeat the required use of headlights to activate the wags. You have to install I diode somewhere I believe near the PCM. I can get it scanned and upload it on the 'net.
Otherwise installation was a breeze. I am actually in the process of uninstalling everything from that truck.
Posted: Mon Nov 03, 2003 6:53 am
by jim
The relay is what keeps you from turning on the headlight for the WW to operate.
These truck switch BOTH the ground and the hot side!
Posted: Mon Nov 03, 2003 11:37 am
by apco25
I already have that pic - its on the sound-off and galls website. 10400 Diode across the enable lead for the headlights. Sound-off makes no mention of the relay.
Posted: Mon Nov 03, 2003 4:10 pm
by FMROB
Hello, If I remember correctly in my 2002 yukon xl the headlights are negative switched, with separate drl bulbs. The problem is that the HD need to be on in order for the HL flasher to work. So you need to power the white wire of the HL switch when the HL flasher is switched to the on position. The older 99 1/2 and below are positive switched, and I don't believe that they have changed the desing again.....PS One of the better HL flashers to use/stock is the UHF2150a, which does both positive and negative switched systems....Rob
Posted: Mon Nov 03, 2003 4:45 pm
by nmfire10
You can flash anything with any flasher given the proper technique and inginuity.
Posted: Mon Nov 03, 2003 5:22 pm
by jim
Late 2003 went back to positive switched on the full-size!
Don't ya love it?
Posted: Mon Nov 03, 2003 8:02 pm
by apco25
Define late 2003? My truck was ordered in January and delivered in March.
Posted: Tue Nov 04, 2003 9:29 am
by FMROB
No kiddin,,,,,I havn't worked on a new, spankin new gm suv yet, So they went back to + switched, oh well. That is why the uhf2150a is a nice flasher to keep in stock, it will do both in one unit. A few more wires to connect and conceal, but it works well...Post more info as it comes available. Thanks, Rob
GMC SUV headlight flasher
Posted: Tue Nov 04, 2003 12:33 pm
by Mike in CT
My late 99 GMC Suburban with DRL... single headlights, the LS K2500 cheapie tank. neg switched.
the guys in the shop 1) couldn't find the DRL module (wasnt where it was claimed to be under the dash!!), 2) and when they found it, the color coding was different... 3) paranoid of setting the thing on fire...
they installed two clear hideaways in the clear running / signal light lenses... has been "doin the job" rather nicely.
they got off easy...
Mike in CT
Posted: Tue Nov 04, 2003 2:15 pm
by apco25
I considered doing the same thing to make life easier - use 2 50w halogen hide-a-way bulbs and leave the factory wiring alone
Considering I've got 4 strobe tubes go in up front plus a set of LED lights in the grill I should be fine.
Who knows maybe I'll get the bug to do the headlights anyway
Posted: Tue Nov 04, 2003 5:39 pm
by jim
GM can't make their minds up on anything!
Posted: Fri Aug 25, 2006 10:00 am
by thowle
I have the Whelen UHF2150A headlight flasher, and have it installed... but I ran into a few problems.
Try to understand this if possible, the way I word it might not make sense, but I hope it does
When I engage the flasher, it will work.. however under certain conditions it won't work right.
If you have the headlights on (parking, headlights, high beams, or not high beams) the flasher will NOT work.
If you have the headlights OFF, but have had the high beams on (meaning, the high beam switch is in the ON position, but they aren't burning since the headlights are off) then the flasher will work perfect.
However again, if you have the headlights OFF, and the high beam switch is in the off position, the flasher flashes the lights ... but it's very dim.
Not really sure what the problem is, if you could help me out at all I'd appreciate it.
Thanks,
Travis
Posted: Sat Aug 26, 2006 2:02 pm
by Jim202
Sounds like you didn't wire it up correctly.
Jim
thowle wrote:I have the Whelen UHF2150A headlight flasher, and have it installed... but I ran into a few problems.
Try to understand this if possible, the way I word it might not make sense, but I hope it does :)
When I engage the flasher, it will work.. however under certain conditions it won't work right.
If you have the headlights on (parking, headlights, high beams, or not high beams) the flasher will NOT work.
If you have the headlights OFF, but have had the high beams on (meaning, the high beam switch is in the ON position, but they aren't burning since the headlights are off) then the flasher will work perfect.
However again, if you have the headlights OFF, and the high beam switch is in the off position, the flasher flashes the lights ... but it's very dim.
Not really sure what the problem is, if you could help me out at all I'd appreciate it.
Thanks,
Travis