Weird harness question
- Thread starter Don W.
- Start date
Don W.
Stab it and steer it
Re: Weird harness question
Thanks. I've had the drivers side partially out. C100 where it passes through to the fuse block. I was thinking more of the ECM harness. Piece of cake with the engine out. Just wondering about if it's in.
Ya, I know there's a gazillion connections. Just makes it fun... Not.
'preciate it
Thanks. I've had the drivers side partially out. C100 where it passes through to the fuse block. I was thinking more of the ECM harness. Piece of cake with the engine out. Just wondering about if it's in.
Ya, I know there's a gazillion connections. Just makes it fun... Not.
'preciate it
Aeroking
e.i.
Re: Weird harness question
The engine harness is on the passenger side, and does not have a plug. The only plug is at the ECM. To pull it out, you have to pull the grommet off with it, and pull all the sensor plugs into the cab. Probably need to depin the fuel injector harness plug.
The driver side harness only has a couple engine wires in it. The plug is most likely siliconed in place.
The engine harness is on the passenger side, and does not have a plug. The only plug is at the ECM. To pull it out, you have to pull the grommet off with it, and pull all the sensor plugs into the cab. Probably need to depin the fuel injector harness plug.
The driver side harness only has a couple engine wires in it. The plug is most likely siliconed in place.
Don W.
Stab it and steer it
Re: Weird harness question
I ended up not removing it. I could have but didn't. The glued in part is "C100" at the firewall. Look in the middle of that and there is a bolt that holds the thing together. The glue is a sealant GM applies. Once you get that connector off look for two small hex headed screws that hold the Fuse panel up against the firewall if you want take the fuse block down.
There are connections at the ECM, dist, oil pres sender, starter, Coil, just to name the ones I can think of.
Why are you thinking of removing it?
My reason was I had a gut feeling that there were poor connections between that harness and the fuse block. So I took it down from inside the cab. Great fun. There are actually three pieces to this mess. The piece you see on the engine compartment side, the fuse block that you see from inside and a third piece behind the fuse block. Huge mess of wires. you'll need patience, perseverance, and caution.
Regarding my poor connections I worked on them but have no actual proof that I fixed anything. I do see a slight increase in voltage at the cig lighter feeding the inverter for the laptop but that is very subjective.
If you ask DaveP he'll probably tell you he's never seen a problem with C100.
I ended up not removing it. I could have but didn't. The glued in part is "C100" at the firewall. Look in the middle of that and there is a bolt that holds the thing together. The glue is a sealant GM applies. Once you get that connector off look for two small hex headed screws that hold the Fuse panel up against the firewall if you want take the fuse block down.
There are connections at the ECM, dist, oil pres sender, starter, Coil, just to name the ones I can think of.
Why are you thinking of removing it?
My reason was I had a gut feeling that there were poor connections between that harness and the fuse block. So I took it down from inside the cab. Great fun. There are actually three pieces to this mess. The piece you see on the engine compartment side, the fuse block that you see from inside and a third piece behind the fuse block. Huge mess of wires. you'll need patience, perseverance, and caution.
Regarding my poor connections I worked on them but have no actual proof that I fixed anything. I do see a slight increase in voltage at the cig lighter feeding the inverter for the laptop but that is very subjective.
If you ask DaveP he'll probably tell you he's never seen a problem with C100.
Re: Weird harness question
I was working on pulling the engine out and have been gutting out the complete engine compartment, but previously I did a bunch of rewiring and didn't like the layout of the harness and was considering having a fuse block in the engine bay like more modern vehicles. I am 6'1" and was laying upside down on the seat and the floor to spend time understanding all the wiring...that got old. From some of the other research I did, on the site, it doesn't seem worth it, but I did want to clean it up (egr,abs,cruise,etc).
I have also noticed that I think I can get to the 2 top transmission bolts if I get most of the harness out of the way, behind the engine block...along with other stuff of course.
Thanks for the help, I will see how much of this I can pull apart....or want to pull apart.
Jon
I was working on pulling the engine out and have been gutting out the complete engine compartment, but previously I did a bunch of rewiring and didn't like the layout of the harness and was considering having a fuse block in the engine bay like more modern vehicles. I am 6'1" and was laying upside down on the seat and the floor to spend time understanding all the wiring...that got old. From some of the other research I did, on the site, it doesn't seem worth it, but I did want to clean it up (egr,abs,cruise,etc).
I have also noticed that I think I can get to the 2 top transmission bolts if I get most of the harness out of the way, behind the engine block...along with other stuff of course.
Thanks for the help, I will see how much of this I can pull apart....or want to pull apart.
Jon
Don W.
Stab it and steer it
Re: Weird harness question
With all due respect, IMHO attempting to change the harness layout is nuts :rotf: there are a LOT of wires. If you're gonna remove the big harness that goes across the compartment the C100 on the engine/firewall side had 3 different connections/looms. The big one that goes across the engine compartment, a small one that goes to the rear (tail lights, etc) and a third that, IIRC is the front lights, ABS stuff. That connector WILL come apart. It's a puzzle but once you figure it out it comes right apart without breaking anything. Then you can remove that harness. It goes through a big grommet at the firewall then to the ECM. disconnect the ECM and I believe those wires will come through that hole. Then you have the harness in your hand. I probably forgot something but that's most of it.
And BTW working under the dash is MUCH easier if you take out the seat. 4 nuts and its out. Big difference.
With all due respect, IMHO attempting to change the harness layout is nuts :rotf: there are a LOT of wires. If you're gonna remove the big harness that goes across the compartment the C100 on the engine/firewall side had 3 different connections/looms. The big one that goes across the engine compartment, a small one that goes to the rear (tail lights, etc) and a third that, IIRC is the front lights, ABS stuff. That connector WILL come apart. It's a puzzle but once you figure it out it comes right apart without breaking anything. Then you can remove that harness. It goes through a big grommet at the firewall then to the ECM. disconnect the ECM and I believe those wires will come through that hole. Then you have the harness in your hand. I probably forgot something but that's most of it.
And BTW working under the dash is MUCH easier if you take out the seat. 4 nuts and its out. Big difference.
Re: Weird harness question
Haha, yes...the seat will come out next time.
But yes, I agree with you, I don't want to rewire everything...I originally thought I could eliminate the fuse block with a milspec bulkhead, but I don't see that being possible.
I'll go back and play with the c100...I am definitely pulling the engine harness out and rewiring/cleanup.
Thanks for the help.
Haha, yes...the seat will come out next time.
But yes, I agree with you, I don't want to rewire everything...I originally thought I could eliminate the fuse block with a milspec bulkhead, but I don't see that being possible.
I'll go back and play with the c100...I am definitely pulling the engine harness out and rewiring/cleanup.
Thanks for the help.