Thread: Wires cut in firewall

Splice wire with butt crimp type, heat shrink for added measure. done!

He already stated that he cannot see the wires. You cannot crimp what you cannot see.

Originally Posted by slick2500

He already stated that he cannot see the wires. You cannot crimp what you cannot see.

Forgive my skimming! Lol


Youll have to pull carpet and padding to get a look at wires and fix.

Have you tried to reach it from under the vehicle? Jack car up and get under there... Should be accessible then.

What year is the car?

A 97-03 should have protected blob down there that goes through a big boot. Also..I would suggest heat shrink and soldering the wires. Crimp connectors don't make the best connections. They only touch where the crimp is located. They aren't weatherproof and are susceptible to corrosion etc when in the elements.

Well Skippy.. You say you used to do wiring. Technically I'm talking about the passthrough that GM labels P100. It's a non-connectors firewall passthrough that W bodies have. It's location is about 6 inches to the right of the center console at the base of the firewall. It can be found inside the car by pulling back the passenger side carpeting or under the car by the passenger side rubber boot on the inner tie rod of the power steering rack.

From there the wiring runs along the passengerside body rail.


In this pic. On the left side of the picture, just right of the inner boot on the rack is a silver clamp, right above that you can see part of a square rubber piece. That is P100

Originally Posted by skippy

Hey guys i'm new here. Just bought a grand prix gt for a really good price only to realize why afterward. Front left signal light doesn't work and neither does the trunk button. I did some investigating and noticed the problem is in the firewall. The guy drilled a hole into the firewall on the passenger side and there seems to be some broken wires in there. I cannot see the wires but I put a screwdriver in the hole and the trunk popped open so I know thats the problem. So question guys....How do i go about fixing this?

Originally Posted by coolone

Forgive my skimming! Lol


Youll have to pull carpet and padding to get a look at wires and fix.

Originally Posted by coolone

Have you tried to reach it from under the vehicle? Jack car up and get under there... Should be accessible then.

Originally Posted by BillBoost37

Well Skippy.. You say you used to do wiring. Technically I'm talking about the passthrough that GM labels P100. It's a non-connectors firewall passthrough that W bodies have. It's location is about 6 inches to the right of the center console at the base of the firewall. It can be found inside the car by pulling back the passenger side carpeting or under the car by the passenger side rubber boot on the inner tie rod of the power steering rack.

From there the wiring runs along the passengerside body rail.


In this pic. On the left side of the picture, just right of the inner boot on the rack is a silver clamp, right above that you can see part of a square rubber piece. That is P100

Originally Posted by skippy

ok so you're saying to jack my car up and get inside there and somehow patch these wires?

So you ask... And get offered help and even a picture map to where the wires should be... There should be no question then to your original question!

You WILL have to get in there, under ere and/or around there in order to fix it, yes!


Bill... Thats an insanely clean engine bay, was car new then? Omg... Lol

A brain is a terrible thing to waste!

First off, have you even tried what suggestions were given you?

Secondly, you might have experience installing wires, but obviously not trouble shooting. Two entirely different animals.

Common sense is an oxymoron, if it's so common, why do so few possess it?

You were given EXAMPLES and SUGGESTIONS on how to address you problem. I know exactly what you are saying and what the problem is. But you've got to physically get dirty, wedge your hand into impossible spots blindly and incredibly fix an unfixable problem. Want specifics? Ok...

Id pull the carpet and find the spot where you stick the screwdriver and make things work, obviously this is where a wire is shorting or cut. Yes, you will have to take things apart, including maybe your dash, the vents, the blower fan, etc. I would then go underneath the vehicle and have someone move the harness that is shorted so I can see it coming through the firewall via movement... Then I would OPEN the harness up on both sides and start pulling each wire trying to see if it or they are broken, if it is, it will pull out of the firewall. Easy fix from that point forward. Otherwise, it's a short and harder to find. If its a short, with wiring diagram in hand, I would identify the wires for the circuits you mention are effected. I would just cut those, replace the wires from engine bay to the underside of the dashboard. I would en test everything prior to reassembly and make sure my beers are on ice for a victory celebration!

Otherwise, just deal with it or sell the car.
Happy Trails!