# Flasher help 2003 Tahoe



## wensteph (Jan 23, 2010)

This seems to be the most knowledgeable forum out there on emergency lighting so I'm hoping someone can/will help with my problem.

I've got an '03 Tahoe with that year's wiring (green w/blk high beam wire) and a SoundOff ETHFSS-SP flasher. The flasher is wired correctly. I tapped the high beam wiring on the driver side. 

The flasher works as it is supposed to when switched on. When I hit my high beams the override works and both my high beams come on bright and strong. The problem is when the flasher is OFF and I turn on my high beams. The passenger side is strong and bright, but the driver side flashes a pattern with a weak and anemic light. I don't know why I am getting a pattern with the flasher off or why it is a weak light. I contacted SoundOff and stumped their technical service guy. Not having any other idea, he thought maybe the unit was defective and sent out a new one. Same thing happens with the new one. 

Hoping someone can help.


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## RBRONKEMA GHTFD (Dec 17, 2006)

Sounds like the power feeding that high beam light is back feeding to the flasher. Have you tried cutting the wire that feeds that high beam from the flasher? Maybe you need to add a switch to that wire? That's a first I've heard about that. I doubt this is possible but maybe the tahoe is a negative powered headlight system? I know some vehicals are like that. B&B would be able to tell you if you do.


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## SafetyLighting (Jul 23, 2005)

Describe how you wired it please. Did you just install it, or has it been in for awhile and you just started having problems with it?


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## wensteph (Jan 23, 2010)

SafetyLighting;972397 said:


> Describe how you wired it please. Did you just install it, or has it been in for awhile and you just started having problems with it?


It was this way from first installation. Replaced the original unit and the second one behaves the same way.

I cut the green/black high beam wire on the driver side (that is the side that weakly flashes when the flasher is turned OFF and the high beam switch is on). The yellow from the flasher is crimped to the green/blk that runs to the high bulb and the blue is crimped to the other part of the green/black that runs back into the wiring harness. The flasher green is grounded. The flasher white is crimped to a line running to the + user buss under the fuse box that is on top the driver side wheel well. This is the same as a direct connect to the + battery connection. The flasher red is crimped to the positive coming from my switch. There is a black wire that is supposed to tie into the parking light if your state requires the flasher to be off when the parking lights are on. This wire is not connected. The last wire is red/black and is used to change the flash pattern. This matches the SoundOff instruction sheet and sounded fine to the SoundOff tech guy when I ran it by him. This SoundOff unit is solid state and the instructions make no mention of diodes or additional relays as are mentioned with some mechanical or thermal flashers.

I know that GM went from a negative switched to positive switched system between the '02 and '03 model year. The positive switched '03 has a green/blk high beam wire, which mine has. I'll point out again that the flasher works *perfectly* when turned on. Both high beams come on when the turn signal stalk switch is activated. Things are perfect until the flasher is OFF and then the passenger high works as it should, but the driver side (the side I made my connections to) weakly flashes. If the flasher is OFF, why is it flashing? And then, of course, why weakly?

Should I also post this over on the Chevy Truck forum?


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## SafetyLighting (Jul 23, 2005)

I believe it is against forum rules to double post, and this is the correct place for this thread.

What size fuse are you using on the *********** feed?

Also check your factory high beam fuses.

Just so you are aware, this flasher is not isolated.


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## Maine_Train (Dec 16, 2009)

Assuming you're in Savannah, GA (four other states, including NY, have a place with the name spelled the same way), you might want to check state law before installing a headlight flasher. [Specifically Title 40, Code Section 40-8-94.1(b). I understand that bill passed in March '04.] 
If you've got the permit or whatever, then forge ahead. Otherwise, it could end up costing you more than what you spent on the flasher.
Just sayin'.


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## wensteph (Jan 23, 2010)

Maine_Train, I'm a firefighter so I'm covered under GA code. Thanks for looking out for me. 

John, I'm rechecking my connections because of your not isolated comment. I'm feeding the flasher and the rear hide-a-ways off of a single wire to the buss connection under the fuse block. I think I'll put each circuit on a separate power power feed just to do something different. I've got the power feed fused at 10 amp just because the headlight fuses are 10's. I checked and both high and low factory fuses are OK.


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## Maine_Train (Dec 16, 2009)

wensteph;973806 said:


> Maine_Train, I'm a firefighter so I'm covered under GA code. Thanks for looking out for me.


Rock on, Bro. Stay safe.









Good luck with the "electrical mysteries." John can probably walk you through that stuff okay.


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## SafetyLighting (Jul 23, 2005)

wensteph;973806 said:


> Maine_Train, I'm a firefighter so I'm covered under GA code. Thanks for looking out for me.
> 
> John, I'm rechecking my connections because of your not isolated comment. I'm feeding the flasher and the rear hide-a-ways off of a single wire to the buss connection under the fuse block. I think I'll put each circuit on a separate power power feed just to do something different. I've got the power feed fused at 10 amp just because the headlight fuses are 10's. I checked and both high and low factory fuses are OK.


The flasher should be fused at 15 amps on it's own circuit. I don't think that has anything to do with your current problem, but it should prevent any other problems in the future.

For some reason, I'm thinking that flasher needs to be installed on the passenger side. I know I've seen this problem, but can't for the life of me remember what we found the issue to be. I have the schematic for those headlights, and there isn't anything remarkably different. The headlights are activated on one relay for high, and one for low.

You said your positive connection is on buss "under the fuse block". Are you talking about the studs on the side of the underhood electrical center?


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## wensteph (Jan 23, 2010)

John,

Yes, I tied on to the studs on the underhood electrical center. 

I'll run a dedicated positive to the flasher, up the fuse to 15 amp and wire the flasher over on the passenger side high beam. Thanks for your help and I'll post what happens.

I checked out your website. You do nice work. To all who read this....sometimes it's just better to find a good company that does this for a living and just write the check and be done with it.


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## SafetyLighting (Jul 23, 2005)

I appreciate that, thank you.

I don't know if any of that will fix your issue, because I can't see anything electrically different from the Driver and passenger side, but try it and see what happens. The Passenger side high beam _should be _ Dark Green with a White tracer. Make sure you test it first.


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## wensteph (Jan 23, 2010)

Argh. That moved the weak light over to the passenger side. I put the flasher on a separate power lead and moved it to the passenger side. 

Beats the heck out of me.


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## SafetyLighting (Jul 23, 2005)

Ok, well, problem fixed! Your driver side light is fine now. LOLOL. Ok, I'm leaving the office now. When I get home I'm going to spend somemore time on this.


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## SafetyLighting (Jul 23, 2005)

What happens when you remove the fuse from the flasher and turn on your high beams?


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## SafetyLighting (Jul 23, 2005)

Also, is the pattern that flashes when the unit is off, the same pattern as when it is on?


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## wensteph (Jan 23, 2010)

It makes no difference if the fuse is in or out.

With the fuse OUT and no power to the 12v lead.

Flasher switch on, high beams on: both high beams steady on, but at night it was noticeable that the cut passenger side high beam is slightly dimmer than driver side. Same as with fuse in.

Flasher switch off, high beams on: passenger side high beam (cut side) weakly flashes at what looks to be at double the speed. Driver side is steady bright. I have the pattern set to single flash. Same as with fuse in. 

Fuse in, low beams on, flasher switch on, the flasher works as it should. Fuse out, low beams on, flasher doesn't work. Which, again, is as it should. 

I don't have a multimeter, but with a probe I have power to the 12v lead downstream from the fuse when the fuse is in and I have power on the hot lead from the switch to the flasher. 

John, I'm hoping you're looking at this as an intriguing and interesting professional challenge. You're going above and beyond trying to help me.


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## SafetyLighting (Jul 23, 2005)

No problem at all, I wish you were closer so I could look at it with you. Something is going on and I don't know what it is or why. The sure fix is to get an Isolated flasher. Who did you speak to at SoundOff? Im going to get them to send you an isolated flasher for the one you have. Also tell me what the other wire colors are on both headlights, i just want to be sure GM didn't do something funky.


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## wensteph (Jan 23, 2010)

Update. I'm going with the isolated flasher per John's suggestion. I'm certain my problem is with my particular vehicle and not SoundOff's product. GM went from a negative switched lighting system in '02 to a positive switched system '03 and there is probably some cross-over parts in making the change. 

Thanks to all who read this thread and gave thought to a solution, and particular thanks to John for his time and effort to help me.


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## andyman0291 (Oct 18, 2008)

im actually having the same problem with a sound off flasher...


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## SafetyLighting (Jul 23, 2005)

What type of vehicle?


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## andyman0291 (Oct 18, 2008)

2005 ford explorer

i appreciate any help john.


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## SafetyLighting (Jul 23, 2005)

No problem Andy. I need more info though. What model flasher and what exactly is or isn't happening? Did you just install it or has it been installed for awhile and the problem just started?


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## andyman0291 (Oct 18, 2008)

first name is actually tom. last name andrews, everyone gets them confused and ends up calling me andrew thomas. hahah. 

per our phone convo earlier, i will get you that code later.


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## andyman0291 (Oct 18, 2008)

did you talk to soundoff john?


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## SafetyLighting (Jul 23, 2005)

I was waiting for the date code.


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## andyman0291 (Oct 18, 2008)

the only thing i saw on it was a serial number 017048


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## SafetyLighting (Jul 23, 2005)

k, standby


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## SafetyLighting (Jul 23, 2005)

You have the white wire run straight to the battery with a fuse right?


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## andyman0291 (Oct 18, 2008)

ill have to double check on the color, but i believe so.


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