Alt Headlights Question

YoChief · Post by **YoChief** » Mon Oct 21, 2002 10:11 am

Have to install a Whelen UHF-2150A Headlight flasher in a 2002 Police Package (Okay, Special Service Package for you purists) Tahoe.

The Tahoe had the daytime running lights disconnected at the factory.

Question is: Is the vehicle headlights positive-side switched or negative-side switched? It makes a difference on the instructions.

Also any advice from anyone who has done a similar install!

Thanks...

Post by **Code3Response** » Mon Oct 21, 2002 10:50 am

yo yo yo! Do you have any info on the Special Service pacakge 2002/2003 Tahoes? Im goign to be buying a Tahoe in a couple of months and am going to get a Special Service Tahoe. (dont bug me on how its not right to get one, the "illegal" word doesnt need to come into play

) Gonna have a good friend (actually the owner) of the chevy dealer here get one, and he said it shouldnt be a problem. Whats teh Special Service like? Any special options you can get? Differences in it, etc? Thanks Yo!

YoChief · Post by **YoChief** » Mon Oct 21, 2002 12:18 pm

Gee, I got all excited, I thought someone was going to help me with my install.

The Special Service Package is just beefed up suspension, special alternator (although still 130A like the civilian version, it has a higher charge rate at idle), vomit proof carpeting (rubber flooring), vinal covered seats, dual batteries, and a plain vanilla exterior. Things like that. The 2002 was called a "Special Service Package" because Chevy doesn't rate it for pursuit. Rumor has it the 2003 package will be and will go back to being called a "Police Package".

It IS fast. And you can get dual spotlights, etc., all the neat stuff.

One bad thing of note (if you are going to install a light bar) the thing comes with a roof rack. I saw a pretty nifty bracket that uses the two roof rack rails on Wattco's web site. Otherwise the light bar is not visable from the rear until you get back aways because the suspension leans the body forward so much.

One GREAT thing of note. It comes with bucket seats and the little third seat in the middle. The middle seat just unbolts and Waa Laa! a place to install Troy consoles, etc.!

It is stripped down though. If you are looking for resale value, forget it.

......And what's wrong with buying police vehicles? Basic chick magnet and I love the stares it draws from the locals when you drive though a new town.

izzifureal · Post by **izzifureal** » Mon Oct 21, 2002 9:49 pm

i believe that it's the switchd ground.....

nmfire10 · Post by **nmfire10** » Tue Oct 22, 2002 4:26 am

I'm not sure about which the Tahoe uses. If I had to bet money, I would go with the ground side switching. That seems to be the new thing lately. It is pretty easy to figure out with voltmeter.

The 2150A is very easy to hook up and it has wires for both positive and negative switching. Just follow the wire chart and you'll be golden.

YoChief · Post by **YoChief** » Tue Oct 22, 2002 11:46 am

Attention Installers!

Okay guys, here it is straight from Whelen's service desk:

"Flasher will not work with that vehicle."

My concern was the DRL's that had been disconnected. That's a factory option you specify when you buy the police package Tahoe. Lots of PD and FD types don't want the lights on when the engines is running, especially at night when they're trying to be sneaky.

I used a VOM and suspected the headlights were negative-side switched. The DRL's are positive switched and they are normally co-mingled with the headlight system. My concern was if I wired a headlight flasher incorrectly would I be needing a quick visit from the local fire department.

Glad I contacted Whelen first....

Thanks for the replys tho....

KitN1MCC · Post by **KitN1MCC** » Sun Oct 27, 2002 7:50 am

Ahh but what the Service Desk Did not mention Was.That you can get the 50 watt halogen Plug in Hide-a-ways.
They look great

(Btw i was one of the People who helped discover they did not work)

Flametamer · Post by **Flametamer** » Mon Oct 28, 2002 5:41 am

To disable the DRL's on 99 and newer Chevys, just pull the 10 amp fuse under the hood. The automatic headlights will still work though. I have been told the only way to kill them is to pull the wiring harness from the sensor on the dash and replace the sensor with the appropriate value resistor.

DT

KitN1MCC · Post by **KitN1MCC** » Mon Oct 28, 2002 6:14 pm

Actually that is not true i heard in the Pre 2003 you press the dome light button 3 times it goes Ding and they turn off.

On my new 2003 2500Hd there is a Selection on the. on the swich it is momentary you can turn the auto matic off and stuff.

But why get the Special Vehicle Package and get all the nasty rubber mat and stuff. just get the regualr package and get the Snow plow Prep.Heavy Duty Front Bigger alternator .

My Truck came with it But then again it is a Diesel

TWL911 · Post by **TWL911** » Mon Nov 11, 2002 6:31 am

I have a 99 GMC Sierra, this is the one year that you CANNOT shut off the headlights at night. What I want to know is if anyone has successfully bypassed the ambient light sensor? if so how? is it a resistor, or and open and closed switch? My main problem right now is I can't get to the wiring harness from the sensor without removing the entire dash. I want to be able to put in a bypass switch to be able to shut off the auto headlights when I am parked on the side of the road. Can anybody help??

KitN1MCC · Post by **KitN1MCC** » Mon Nov 11, 2002 6:23 pm

What i had to do in the lumina . used to just get it between the postitions and they would go off

copcarguy · Post by **copcarguy** » Wed Nov 13, 2002 9:52 pm

HERES THE BEEF--

TO DISABLE AUTO HEADLIGHT AT NIGHT- UNPLUG THE SENSOR ON THE TOP OF THE DASH(LITTLE DOME SMOKED GLASS THING) UNPLUG THE WIRE HARNESS (2 WIRES IN IT) PLUG A 1K RESISTOR IN THE NOW EMPTY WIRE CONNECTOR AND TAPE IT UP. DO NOT PLUG BACK INTO LIGHT SENSOR.

THE EASIEST WAY TO TELL IF YOU HAVE A GROUND OR POSITIVE HEADLIGHT SYSTEM IN MOST AMERICAN MADE CARS IS THE COLORS OF THE WIRES. HERE IS A GENERAL AUTOMOTIVE RULE THAT WORKS MOST OF THE TIME. IF THERE IS A BLACK WIRE AND SOME OTHER COLOR GOING TO THE BRIGHT HEADLIGHT ITS POS SWITCHED(IE. BLACK AND GREEN); IF THERE ARE 2 WIRES GOING TO THE BRIGHT HEADLIGHT AND THEY ARE BOTH NOT BLACK, USUALLY ITS NEG SWITCHED(IE. BLUE AND GREEN).

DRL CUT OFF WITH THE CYCLE OF THE DOME OVER RIDE SWITCH. IF YOU TAP THE DOME OVER RIDE SWITCH, THE DRL LIGHTS WILL TURN OFF (2000 AND NEWER) AND WILL REMAIN OFF UNTILL YOU TURN OFF YOUR VEHICLE AND RE-START IT. THEY WILL THEN TURN BACK ON UNTIL YOU CYCLE THE DOME OVER RIDE SWITCH AGAIN.

THE BEST WAY TO DEFEAT DRL ON TAHOES IS TO PULL THE 10 AMP DRL FUSE.

jmr061 · Post by **jmr061** » Thu Nov 14, 2002 11:34 am

Regarding the DRL/Auto Headlights at night. I have a 1997 Lumina that has this. There is a 10 amp fuse that supplies power to the DRL module. Pull it out and it disables the auto headlights at night and the daytime running lights. I actually cut the power wire from the fuse to the DRL module and put in a relay and connected it to my switch box so I can kill it by pushing a switch. (actually this is similar to what the night-time cutoff does on a Lumina police package) Of course it helped having the complete service manual with wiring diagrams for my car but it wouldn't have been to difficult to trace.

Jason

ExKa|iBuR · Post by **ExKa|iBuR** » Fri Nov 15, 2002 11:39 am

WEll, what I did in my old car to disable the automatic headlights was this:

I hooked up a switch to the Parking Brake sensor.

So, if I turn the switch on before I start the vehicle, the headlights and tail lights won't come on unless I either release the switch, or, better yet, use the manual headlight switches.

This doesn't cause anything bad to happen, except you have the annoying light on saying your E-Brake is on.

Mike

Alt Headlights Question

Alt Headlights Question

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