Mystery Wires

[JamesSloth]

Intro photo is just a nice shot, second photo is where i need the help.
I have two yellow female plugs that look like air bag plugs and i have no were near by to plug them into, fairly certain the harness is in the wrong spot from the body shop that did my frame swap.

Second issue is the blue and orange cable that run from here to the tow hookup that are also not connected to anything. No idea where they need to be plugged in at or if theyre an aftermark something or other that was uncovered during the frame swap.

Overall im really stumped as i have no brakes and no rear lights and i dont see anything obvious as to why aside from the photo, and one pigtail with no mate near the tow hitch that gets 12v on one of its 4 pins

 

[Eman85]

The blue and orange are most likely the power and brake signal leads for the trailer connector. Blue would go to a brake controller if you install one and the orange to the fuse block stud for aux power. Be sure it's fused.

 

[exp500]

Check your front end for crash sensor for air bags, you might be missing that front harness.
As far as brakes, lines were disconnected for swap. Bleed them and ABS.
Manuals here- Free Car Service Manuals from LEMON Manuals

 

[Eman85]

I looked at our 97 Tahoe and the yellow connector goes from the frt. harness to another yellow connector from the main through firewall harness.

 

[JamesSloth]

Check your front end for crash sensor for air bags, you might be missing that front harness.
As far as brakes, lines were disconnected for swap. Bleed them and ABS.
Manuals here- Free Car Service Manuals from LEMON Manuals

Alright brakes and abs bled. They feel miles better but still have brake and abs light on and definitely not working brakes. Is this just a case of not bleeding enough?

 

[JamesSloth]

I looked at our 97 Tahoe and the yellow connector goes from the frt. harness to another yellow connector from the main through firewall harness.

Possible to get a photo of that. I'm not seeing a mate near there

 

[exp500]

Alright brakes and abs bled. They feel miles better but still have brake and abs light on and definitely not working brakes. Is this just a case of not bleeding enough?

If you used pressure bleeder with a scanner to cycle ABS, then look elsewhere for problem. Otherwise bleed again. About 2 quarts if manual bleeding. Trick- cycle key to on while depressing pedal- will give you one cycle of ABS. If no scanner. RTFM.

 

[JamesSloth]

If you used pressure bleeder with a scanner to cycle ABS, then look elsewhere for problem. Otherwise bleed again. About 2 quarts if manual bleeding. Trick- cycle key to on while depressing pedal- will give you one cycle of ABS. If no scanner. RTFM.

Alright more bleeding it is. Wife is gonna get her leg work out today lol

 

[Fless]

Make sure she doesn't push the pedal to the floor; that can ruin a master cylinder that's not experienced deep piston travel previously. Place a 2x4 or the like on the floorboard to prevent that.

 

[Tonyrodz]

Make sure she doesn't push the pedal to the floor; that can ruin a master cylinder that's not experienced deep piston travel previously. Place a 2x4 or the like on the floorboard to prevent that.

How do you know if you pushed the pedal too far down? What would be the symptoms?

 

[Fless]

How do you know if you pushed the pedal too far down? What would be the symptoms?

Pushing too far can blow the seals on the piston, so the master cylinder would never build enough pressure to fully activate the brakes. Soft pedal and unable to fully bleed the system.

 

[JamesSloth]

If you used pressure bleeder with a scanner to cycle ABS, then look elsewhere for problem. Otherwise bleed again. About 2 quarts if manual bleeding. Trick- cycle key to on while depressing pedal- will give you one cycle of ABS. If no scanner. RTFM.

Did a little digging around on what i thought was an unrelated problem with my obd2 port not scanning, turns out a bad abs module can muck that up, and unplugging it got me reading again. seems like i need a new master cylinder and abs mod. Thanks for all the help!

 

[Eman85]

I don't understand problems people have with brakes on these vehicles. I was a dealer tech when they were new, worked on a lot at my own shop and own a few and have done a lot of brake work over the years. I've never had a problem bleeding them no different then I did on 1960's and 70's vehicles. Master cylinder is easy to diagnose. Buy 2 plugs that fit the MC ports, remove the 2 lines and install the plugs. If the pedal is rock solid the MC is good. If it's spongy it's got air, if it sinks to the floor it's NG.
If you are replacing the MC do some research on putting a NBS MC on, you'll see a much better pedal as they sucked from the day they were built.

 

[JamesSloth]

I don't understand problems people have with brakes on these vehicles. I was a dealer tech when they were new, worked on a lot at my own shop and own a few and have done a lot of brake work over the years. I've never had a problem bleeding them no different then I did on 1960's and 70's vehicles. Master cylinder is easy to diagnose. Buy 2 plugs that fit the MC ports, remove the 2 lines and install the plugs. If the pedal is rock solid the MC is good. If it's spongy it's got air, if it sinks to the floor it's NG.
If you are replacing the MC do some research on putting a NBS MC on, you'll see a much better pedal as they sucked from the day they were built.

I think my issue is I didn't realize how much I needed to bleed. And the NBS master was already the plan since they're inexpensive and easy to put on. The biggest concern for me right now is that my ABS might be shot cause it's causing my OBD2 to not read and they're expensive as hell from my 2 minutes of looking

 

[89Suburban]

I think my issue is I didn't realize how much I needed to bleed. And the NBS master was already the plan since they're inexpensive and easy to put on. The biggest concern for me right now is that my ABS might be shot cause it's causing my OBD2 to not read and they're expensive as hell from my 2 minutes of looking

I like your headlights.

 

[JamesSloth]

I like your headlights.

Nilight on Amazon. Really impressed with their quality, same company for the led bulbs and the side markers were just cheap 40 led guys nothing special

 

[JamesSloth]

Nilight on Amazon. Really impressed with their quality, same company for the led bulbs and the side markers were just cheap 40 led guys nothing special

40 dollar

 

[Tonyrodz]

I like your headlights.

Headlights or "Headlights" lol. J/K

 

[east302]

Not sure if this will help since mine is a 98, but the airbag impact sensor is behind the grille. There’s a connector right at the firewall. The picture isn’t the best, but I drew where the wires go.

 

[JamesSloth]

Not sure if this will help since mine is a 98, but the airbag impact sensor is behind the grille. There’s a connector right at the firewall. The picture isn’t the best, but I drew where the wires go.

View attachment 485591
View attachment 485592

Very odd. On my truck that's a 2 wire yellow connector and it's complete, but I have a harness coming from under the cab that has an empty 4 wire connector and an empty 3 wire from the harness going to my ABS