Electrical help or shop recommendations

[J-mobzz]

I recently picked up a 2017 Chevy Tahoe at auction that was a Utah county sheriffs vehicle. I’ve been doing quite a bit of work to it to make it look not like a cop car and more comfortable/refined inside.

The front and rear passenger blinkers and rear brake light are not working. The tail light is working. I’ve checked bulbs and fuses but that’s about it. I thought it might be an connector or something in the wiring harness but I haven’t been able to find any diagrams online that show any of that stuff so I’m not even sure where to look. These vehicles everything has to be taken apart to get access to anything.

So I would either love a recommendation of a shop or dealership that you trust with electrical work or if you have some pointers I’m actually pretty decent with a multimeter and tracking stuff down I just don’t want to tear everything apart blindly.

 

[J-mobzz]

Correction I’ve checked the rear bulbs not the front. I don’t think a bad front bulb would effect the rear brake/turn though.

 

[Kevin B.]

I'm not much help but I know those rigs get a lot of aftermarket wiring. If you can figure out what locations they tore into the harness at, you might find your trouble spot. I'd start by looking at/behind the fuse box(es).

 

[1969honda]

Vehicle Lighting Specialists (VLS) is the main vendor to most LEOs across the state. They might be worth giving a call to, I know they have a shop not far from Larry Miller Ford on 13th S and another one they opened in Logan.

 

[Spork]

My thought is the police kit plugs in similar to a trailer brake controller, somewhere to start, maybe they didn't plug everything back in tight.

 

[rholbrook]

My BIL had a Tahoe that was never electronically right. He would turn on a blinker and hid wiper blades would turn on. He would plug a trailer into his factory wired trailer plug and his inside lights would turn on if he hit the brakes. The dealer never figured it out and gave him all kinds of excuses.

 

[Pile of parts]

Correction I’ve checked the rear bulbs not the front. I don’t think a bad front bulb would effect the rear brake/turn though.

Did you check the fluid???

🤣🤣🤣

 

[jeeper]

I've had some crazy electrical issues that were all traced back to a bad ground somewhere.

 

[Tonkaman]

I have a power probe wire tracer thingy that’s pretty good at finding open circuits and shorts. Your welcome to borrow it and see if you can trace the wire from the tail lights foreword.

 

[J-mobzz]

I have a power probe wire tracer thingy that’s pretty good at finding open circuits and shorts. Your welcome to borrow it and see if you can trace the wire from the tail lights foreword.

I might take you up on that. After @Spork posted about the control being plug in I looked under the dash and sure enough a big block with 4-5 connections. I think I’ll start with pulling all of those and see if any loose or bent pins may have happened while pulling the controller out.

 

[Tonkaman]

I might take you up on that. After @Spork posted about the control being plug in I looked under the dash and sure enough a big block with 4-5 connections. I think I’ll start with pulling all of those and see if any loose or bent pins may have happened while pulling the controller out.

Hopefully is that simple. Don’t hesitate to come pick up the tracer if not though

 

[UNSTUCK]

Does it have a trailer connector at the rear bumper? You should see if those wires are functioning properly. You could use them to power your lights. Although you may get a “trailer connected” chime at every start up.

 

[Hickey]

Does it have a trailer connector at the rear bumper? You should see if those wires are functioning properly. You could use them to power your lights. Although you may get a “trailer connected” chime at every start up.

They might have messed with that trailer connection harness as well. Check it for damaged pins.

 

[J-mobzz]

Does it have a trailer connector at the rear bumper? You should see if those wires are functioning properly. You could use them to power your lights. Although you may get a “trailer connected” chime at every start up.

It does and that’s a decent idea. I should get it back from the shop doing the interior and tint tomorrow and I plans to start by looking at the plugs under the dash. It’s a nice enough vehicle id really rather fix the problem but if I have no luck and the local Chevy dealer has no luck I may end up slicing it. Every time I turn the right turn signal on it tells me to check the rear bulb currently and I really would like that to go away and I feel like spicing it wouldn’t do me any good there.
And the trailer connected time would be a little annoying as well. But I’ll keep it in mind as a last resort before I want to burn the thing down or something.

 

[J-mobzz]

They might have messed with that trailer connection harness as well. Check it for damaged pins.

I’ve gone all around the wiring harness I can see from a creeper underneath and everything looks super factory under there so I don’t think they messed with any of the wiring harness in the back half. It’s possible it has maybe been in the front end collision so my guess is either a connector somewhere up in the engine compartment that didn’t get reconnected during some repair or those connectors under the dash where they plug in the lighting control modules.

Or it could just be one of those weird ghost things.

But the more I think about it I have the full service records of the vehicle and those things were ridiculously over maintained like transmission flushes every 25,000 miles and they really got everything they needed so I can’t imagine that the rear bulb warning light would’ve been going on and just gone undocumented or serviced. This has me thinking more and more that some thing was done when they were pulling the police equipment out after it was already taken out of service so I hadn’t thought of that until this thread and it definitely makes me think that there probably is something in that wiring block under the dash where all the connectors would come off and plug into the police equipment.

 

[J-mobzz]

So a little update I’ve been digging through this thing as much as I can without literally taking the engine compartment apart to access things that I’m not even sure what I’m searching for and haven’t had any luck finding the break in the connection. Ultimately I need to take it to the shop but for the time being I’m driving this vehicle because I kind of accidentally jumped my Jetta and I’m in the process of fixing all the damage I did to that and the eagle and van Aren’t exactly The best daily drivers. So I took @UNSTUCK advice and after verifying that the turn signal brake light line was not shorted just tapped into my trailer harness and I now have a working brake light and tail light.

And I was actually incorrect the front turn signal is working it’s just really small and hard to see in daylight. So everything‘s working for now except for when I leave the right turn signal on the warning light comes on the dash saying to check the rear light bulb. It’s a little annoying but it’s better than having to worry about getting pulled over especially with the new super dark window tint I don’t need to give anyone an extra reason to pull me over.

Anyways thanks for the advice everyone and once I get my car back in commission I’ll take and drop this thing off at the shop and hopefully get it fixed correctly. Unless I can come up with a wiring diagram then I’m fairly certain I could figure it out myself.

 

[J-mobzz]

I think you are correct. And there is evidence this happened with external power and ground cables that are part of the SSV package. I have been able to come up with the wiring diagrams for all the SSV stuff added. Although I don't think this is where the problem is. I'm seeing some evidence there was some front end collision work done on the passenger side. Im wondering if that may be where the problem is.