What do I do with wiring harness after CARB swap
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
What do I do with wiring harness after CARB swap
Just curious what everyone does with the tbi/tpi harness after doing a carb swap. PICS please
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Car: 1988 Camaro
Engine: 355, 10.34:1, 249/252 @.050", IK200
Transmission: TH-400, 3500 stall 9.5" converter
Axle/Gears: Ford 9", detroit locker, 3.89 gears
Re: What do I do with wiring harness after CARB swap
Remove it and sell it to someone that needs it.. Or remove it and put it up in storage for later user if needed
Remove, cut out, get rid of all not needed and trash it.
Remove, cut out, get rid of all not needed and trash it.
#3
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Re: What do I do with wiring harness after CARB swap
I completely removed my harness and ECM. There was nothing in it that was needed for a carbed computerless installation. I had to add a circuit for the electric choke but that was it. I reconfigured my ignition too but that was more due to the MSD upgrade than anything else. An HEI distributor will work fine.
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
mine is a 92. not sure if that makes a difference. but the wires in the harness go to the alternator and up by the headlights. I don't need any of it?
#5
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Re: What do I do with wiring harness after CARB swap
I can't commnet on the differences between your 92 and the 86(s) I've worked on. I can say that in my Camaro, there were two distinct harness'. One handles the lighting and few other under hood functions. That harness came directly from the large bulkhead connector located near the brake booster. The other handled engine management. It exited the engine bay by way of the passenger fender and came into the cabin through the kick panel.
Some of the engine mangement has to be taken care of once the ECM is removed.
Cooling fan control will have to be done via the temp switch in cylinder head and hard wired to a realy.
I'm not sure if your gauges were fed via the computer or not. I went the aftermarket gauge route so that wiring is seperate in my case. Coolant temp and oil pressure in particular.
You'll have to source ignition power for the distributor and carb choke.
I'm not sure what you're doing about a fuel pump but the ECM handles it too. I went to at first a mechanical pump, then to an aftermarket external pump (and back again).
Other than that, I had nothing else to consider.
You'll have to deal with your VATS too. Here's a link:
https://www.thirdgen.org/forums/engi...s-ecm-tpi.html
Some of the engine mangement has to be taken care of once the ECM is removed.
Cooling fan control will have to be done via the temp switch in cylinder head and hard wired to a realy.
I'm not sure if your gauges were fed via the computer or not. I went the aftermarket gauge route so that wiring is seperate in my case. Coolant temp and oil pressure in particular.
You'll have to source ignition power for the distributor and carb choke.
I'm not sure what you're doing about a fuel pump but the ECM handles it too. I went to at first a mechanical pump, then to an aftermarket external pump (and back again).
Other than that, I had nothing else to consider.
You'll have to deal with your VATS too. Here's a link:
https://www.thirdgen.org/forums/engi...s-ecm-tpi.html
Last edited by skinny z; 01-02-2015 at 11:35 AM.
#6
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
Ok thank you. I already bypassed vats when i was diagnosing a no crank issue last year. i am setting up a Holley red pump tomorrow so when i run the fuel lines i am going to remove the harness.
#7
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Re: What do I do with wiring harness after CARB swap
Good luck.
Keep us posted.
Keep us posted.
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
still have to find a way to hold the other harness in the bulkhead
#10
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Re: What do I do with wiring harness after CARB swap
You'll need both halves of that connector (C100) to run your vehicle circuits other than those controlled by the ECM.
The ECM harness exits the engine bay through the passenger side fender and goes into the cabin through the kick panel. Most of what's in there isn't needed for a carbed application. Like I said, you will have to supply a few additional circuits to make everything run.
I've attached a pinout list for an 88 Camaro. (It's all I have handy at the moment). You can see the circuits that are involved in the harness you'll pulled out although the pinouts won't be the same.
The ECM harness exits the engine bay through the passenger side fender and goes into the cabin through the kick panel. Most of what's in there isn't needed for a carbed application. Like I said, you will have to supply a few additional circuits to make everything run.
I've attached a pinout list for an 88 Camaro. (It's all I have handy at the moment). You can see the circuits that are involved in the harness you'll pulled out although the pinouts won't be the same.
Last edited by skinny z; 01-03-2015 at 06:03 PM.
#13
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Re: What do I do with wiring harness after CARB swap
What year is that for? I understand that some of the C100 connectors are a 1 year only deal. Others cover a a few years in a row.
#15
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Re: What do I do with wiring harness after CARB swap
So, looking at that, you have a number of circuits in the harness you removed that are needed. Obviously the lighting and wipers but also the TCC, tach and VSS (amongst others).
The harness not listed (to the ECM) would have the engine operating functions. TPS, IAT, MAP, etc. Those are what you can discard for a carb swap.
I'm guessing you have this figured out.
The harness not listed (to the ECM) would have the engine operating functions. TPS, IAT, MAP, etc. Those are what you can discard for a carb swap.
I'm guessing you have this figured out.
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
Yea. the big half of the connector is transmission and engine wires and the small half i left plugged in is lights and wipers
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Engine: 350sbc
Transmission: TH700R4
Axle/Gears: 3.42
Re: What do I do with wiring harness after CARB swap
I think by 92 that the ecu harness maybe all in one with the rest of the harness.
But its easy to remove.just unplug the ecu from the passenger side. And then take off the wire looming.
And take it apart from the starter and alternator and gauges. Then you can reloom the harness with smaller looming as theres only like 5 or 6 wires left. The wording harness for the headlights remains untouched.
But its easy to remove.just unplug the ecu from the passenger side. And then take off the wire looming.
And take it apart from the starter and alternator and gauges. Then you can reloom the harness with smaller looming as theres only like 5 or 6 wires left. The wording harness for the headlights remains untouched.
#21
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Re: What do I do with wiring harness after CARB swap
The wiring for the engine management has to be somewhere. It's not listed in the C100 connector diagram listed. No IAT, TPS, MAP....Just wondering.
Last edited by skinny z; 01-04-2015 at 07:04 PM.
#26
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Re: What do I do with wiring harness after CARB swap
Thar she blows!
(That's what I was referring to)
So to answer your original question (and it looks like you've figured it out), that's the harness that gets discarded for a carb swap.
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Car: 85 iroc with 92 ground effects
Engine: 355 11.1 world product heads
Transmission: t56
Axle/Gears: 3.54 dana 44
Re: What do I do with wiring harness after CARB swap
I took my stock harness and cut out everything I didn't need. I kept the wires for oil pressure, temp, tach, 12v ignition, starter trip, fan switch and reverse lights. Took awhile as I re run everything to clean it up. Ended up with 2 relays. Fan and fuel pump. I have switches in my ash try to turn fuel pump on and switch to bring my fan on whenever.
Also got rid of the junction piece toward the front passenger side and again soldered and shrink wrapped everything
Minimum amount of wires but still used the factory plug.
Also got rid of the junction piece toward the front passenger side and again soldered and shrink wrapped everything
Minimum amount of wires but still used the factory plug.
#29
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
I took my stock harness and cut out everything I didn't need. I kept the wires for oil pressure, temp, tach, 12v ignition, starter trip, fan switch and reverse lights. Took awhile as I re run everything to clean it up. Ended up with 2 relays. Fan and fuel pump. I have switches in my ash try to turn fuel pump on and switch to bring my fan on whenever.
Also got rid of the junction piece toward the front passenger side and again soldered and shrink wrapped everything
Minimum amount of wires but still used the factory plug.
Also got rid of the junction piece toward the front passenger side and again soldered and shrink wrapped everything
Minimum amount of wires but still used the factory plug.
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Car: 85 iroc with 92 ground effects
Engine: 355 11.1 world product heads
Transmission: t56
Axle/Gears: 3.54 dana 44
Re: What do I do with wiring harness after CARB swap
Thanks, just take your time and don't be in a rush
Another tip for the wiring is if you hook the harness back up you should be able to ground certain wires and it will peg the gauge inside. That is how I figured out the feed wire for each gauge. Then follow the wire all the way to the c100 and leave it. Move onto the next. Makes for a nice clean job.
You will have to hotwire your fuel pump as the ecu use to prime the pump and oil sender over a certain pressure kept pump on. The red test wire on the relay with 12v will turn pump on or you the green with white stripe I think.
For the fans you can use the sensor in the head to the factory relay and will work by ground. Also can t a toggle switch into that wire to make a ground to bring fans on manually.
Sorry for rambling but might help you
Another tip for the wiring is if you hook the harness back up you should be able to ground certain wires and it will peg the gauge inside. That is how I figured out the feed wire for each gauge. Then follow the wire all the way to the c100 and leave it. Move onto the next. Makes for a nice clean job.
You will have to hotwire your fuel pump as the ecu use to prime the pump and oil sender over a certain pressure kept pump on. The red test wire on the relay with 12v will turn pump on or you the green with white stripe I think.
For the fans you can use the sensor in the head to the factory relay and will work by ground. Also can t a toggle switch into that wire to make a ground to bring fans on manually.
Sorry for rambling but might help you
#31
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
Yes very helpful. i did switch to a mech. fuel pump so that is one less hassle. what did you do with the speedometer and tach
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Car: 85 iroc with 92 ground effects
Engine: 355 11.1 world product heads
Transmission: t56
Axle/Gears: 3.54 dana 44
Re: What do I do with wiring harness after CARB swap
For the tach I think it was a white off the original coil. Hooked that into my hei
For the speedo I didn't use any of the factory wiring. I have an auto meter speedo. Two wires come off the speed sensor. I grounded one of them to the tunnel and the other went to the back input of my speedo. Autometer is nice because can program the speedo to different rear gears or tire height. You drive 2 miles at 45mph and sets calibration.
For the speedo I didn't use any of the factory wiring. I have an auto meter speedo. Two wires come off the speed sensor. I grounded one of them to the tunnel and the other went to the back input of my speedo. Autometer is nice because can program the speedo to different rear gears or tire height. You drive 2 miles at 45mph and sets calibration.
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Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
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Re: What do I do with wiring harness after CARB swap
Best thing to do is leave them where they are so you can put them back in 6months when you get fed up with the carb
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Car: 87 bird
Engine: enough to break stuff
Transmission: manual th400
Axle/Gears: 4.10
Re: What do I do with wiring harness after CARB swap
if the engine(carb and timing) is set properly they run fine.they start fine, its people who dont know what they are doing that give the issues. people had carbs on everything for like a hundred years. everywhere, from Alaska to mexico.
#37
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Car: 92 RS
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Re: What do I do with wiring harness after CARB swap
https://www.thirdgen.org/forums/carb...carb-swap.html
#39
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Car: 92 RS
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Re: What do I do with wiring harness after CARB swap
Yes used mech fuel pump. every sbc has a spot for it. but might not have lobe on cam.
#40
Re: What do I do with wiring harness after CARB swap
I have fuel pressure regulator. I wish I would've knew before hand. Did you have to rewire anything else. I need all the help I can possibly get.
#41
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
depends on what your hooking up. to make it run you only need 2 wires. starter, distributor
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Car: 1987 Formula 350 Firebird
Engine: Pontiac 400
Transmission: Turbo 400
Re: What do I do with wiring harness after CARB swap
I see the AC runs through the ECM. IS there a good way to bypass it other then wiring in a switch? I also noticed my car (87' Formula) has what I'm guessing is a switch on the power steering pressure line that runs though the ECM. What is that used for? Low pressure warning light maybe?
#45
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Car: 92 RS
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Re: What do I do with wiring harness after CARB swap
Not sure as I did not hook ac back up in mine. And I just left the power steering wires disconnected
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#47
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Car: 92 RS
Engine: Sbc With h/c/i/e holly4150
Transmission: 700r
Re: What do I do with wiring harness after CARB swap
nope just suck it up. Iv only had 2 cars in my life that had ac.
#49
Re: What do I do with wiring harness after CARB swap
Quick question about using manual fuel pump. Did you have to do anything to the stock fuel pump or fuel lines. Other than unplugging the wires to it and hooking the fuel line to the pump?
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Re: What do I do with wiring harness after CARB swap
A handy tip (maybe) for those with a fual pump relay and a toggle switch. There is a much easier/better way to do this. Get a TIMED NO relay, this will close for a set amount of time after triggering the coil with key on. You can have this one trip the main FP relay if you want to keep that stock. Then you can leave the rest of the oem wiring in place and have the parallel wired in oil pressure switch. That will power the FP. If you want to keep the FP relay active during running you cna simply use a rpm trigger (or the unused idiot light terminal on your alternator, it provides 12V to switch off the idiot light - both sides 12V, effectively 0 - when the alt is charging)
Here's my procedure, I rewire the harness with all factory fuse holders, relays etc and simplify some of it (less splices, etc) and clean it up a little so it makes for a clean factory looking install. Not having FI and emissions junk sure helps eliminate clutter
this we do not want anymore
this has since gotten a lot cleaner. I had to repair all the wiring harneses and some other areas because some tool here in the Netherlands who thinks highly of himself (idiot who worked on this car in the past) thinks that proper wiring does not require a soldering iron and shrink sleeve but twisting wires, painters tape or duct tape and luster terminals
Here's my procedure, I rewire the harness with all factory fuse holders, relays etc and simplify some of it (less splices, etc) and clean it up a little so it makes for a clean factory looking install. Not having FI and emissions junk sure helps eliminate clutter
this we do not want anymore
this has since gotten a lot cleaner. I had to repair all the wiring harneses and some other areas because some tool here in the Netherlands who thinks highly of himself (idiot who worked on this car in the past) thinks that proper wiring does not require a soldering iron and shrink sleeve but twisting wires, painters tape or duct tape and luster terminals