Brake Light Issue

[96-BlueSub]

New member got a weird problem with my tail lights/interior lights. I have searched but cannot find the exact issue I am having...

Truck is a 1996 1500 suburban 4x4 stock truck, no mods at all.

Main issues:

brake lights are always on

AC/heat turns on when brake pedal is depressed even when key is removed. This is the most bizarre issue.

overhead and dome lights always on (can be bypassed with dome override button)

Some info:

No alarms on the dash
the brake lights get slightly brighter if you press the pedal but it's almost indiscernible even at night.
Front running/parking lights and headlights work correctly.

Replaced both taillights as first step (were faded anyways)

Checked all fuses and cannot find an obvious grounding or wiring issue.

Next step is brake light switch under the pedal.

Any other ideas I am overlooking?

Thanks,

Dax

 

[someotherguy]

You'll want to download the factory service manual for your truck and inspect ALL the grounds first to be sure none have been left disconnected or gotten damaged.

Beyond a bad or loose ground somewhere it sounds like wiring harness damage.

Richard

 

[Helrazzor]

Where is the best place to download the service manual?

Scott

 

[618 Syndicate]

As suggested, it's likely to be a ground issue.

 

[618 Syndicate]

Where is the best place to download the service manual?

Scott

Do a search on here, you'll find what you need.

 

[df2x4]

Where is the best place to download the service manual?

Scott

Here's a link to the thread, it's stickied at the top of the Engine Performance and Maintenance section.

https://www.gmt400.com/threads/88-95-service-manuals.43575/

 

[96-BlueSub]

You'll want to download the factory service manual for your truck and inspect ALL the grounds first to be sure none have been left disconnected or gotten damaged.

Beyond a bad or loose ground somewhere it sounds like wiring harness damage.

Richard

Ok so I am going to go through all the grounds I can get to then replace the relay and switch. This was my dads old truck and I just want to keep it drivable. The brake light issue Is the biggest concern, really want to be able to drive the truck every once in a while.