Single turbo harness conversion grounding
09-23-12, 04:13 PM
#1
Single turbo harness conversion grounding
I'm in the process of cleaning up my harness for a single conversion + all emissions and idle controls delete. I've been following a write up I found, but now I'm at the last step which involves re-doing some of the grounds and there is a little bit of confusion because my harness is from a JDM car so there are some things that I already didn't have. Not to mention, the write up didn't include an idle air control delete which is where i'm getting thrown off.
Anyways, first question: There are 2 black and white wires that run through the rats nest (the grounds) that also meet back at a junction that also goes out to the idle air control plug. (4 way junction, 2 to rats nest, 1 to IAC, 1 back to ECU pinout). In the write up, they left the iac on so they had a section about re-grounding it properly. Obviously mine is gone now, as well as the 2 rats nest ones so i basically have this junction but none of the wires lead anywhere. Follow the single wire side of that junction, and it goes right back to the ecu pinout. Can I just remove this without affecting any other grounds? It doesn't connect anywhere else but I have no clue if there is some sort of circuitry in the ecu that requires this to go somewhere (electrical stuff is not my forté.)
If you need a picture of what i was trying to describe I can get one but its fairly straight forwards.
Second question, going with an aftermarket fuel rail, I will have no use for the fuel temp plug, so It's going to come off as well. 2 issues here,
1:there is a brown and black wire that leads to a junction going the thermostat housing plug as well as back to the ecu pinout (I think, I didn't check for any other stops on the way but i would assume that's it.) Can I just cut the brown and black wire near the junction and tape it back up, or will doing this mess with a ground anywhere?
2: I've heard of people using a power fc removing this fuel temp plug and having the exhaust temp light come on. People have suggested that instead of removing the 2 wires going back to the plug right back to their respective junction (for brown and black one) and ecu pinout (for the other one) that you should just put an equivalent resistor between the two and leave the rest of the wires alone.
I would like the wires entirely gone if possible but I don't want the light to always be on. Anyone have word about the truth behind this?
Anyways, first question: There are 2 black and white wires that run through the rats nest (the grounds) that also meet back at a junction that also goes out to the idle air control plug. (4 way junction, 2 to rats nest, 1 to IAC, 1 back to ECU pinout). In the write up, they left the iac on so they had a section about re-grounding it properly. Obviously mine is gone now, as well as the 2 rats nest ones so i basically have this junction but none of the wires lead anywhere. Follow the single wire side of that junction, and it goes right back to the ecu pinout. Can I just remove this without affecting any other grounds? It doesn't connect anywhere else but I have no clue if there is some sort of circuitry in the ecu that requires this to go somewhere (electrical stuff is not my forté.)
If you need a picture of what i was trying to describe I can get one but its fairly straight forwards.
Second question, going with an aftermarket fuel rail, I will have no use for the fuel temp plug, so It's going to come off as well. 2 issues here,
1:there is a brown and black wire that leads to a junction going the thermostat housing plug as well as back to the ecu pinout (I think, I didn't check for any other stops on the way but i would assume that's it.) Can I just cut the brown and black wire near the junction and tape it back up, or will doing this mess with a ground anywhere?
2: I've heard of people using a power fc removing this fuel temp plug and having the exhaust temp light come on. People have suggested that instead of removing the 2 wires going back to the plug right back to their respective junction (for brown and black one) and ecu pinout (for the other one) that you should just put an equivalent resistor between the two and leave the rest of the wires alone.
I would like the wires entirely gone if possible but I don't want the light to always be on. Anyone have word about the truth behind this?
09-23-12, 07:46 PM
#2
alright so i've been told to just do away with the fuel temp sensor so it is gone and de-pinned now. Just cut it at the junction.
Just for the ground, here is a pic. I know this blue plug isnt on the usdm wiring harness but regardless, it's the only one that isn't yellow.
Here is a pic of the ground wire and how it ends. There were a few junctions along the way but everything off there has been eliminated so it's basically this one wire ending here.
Can I simply de-pin this or should I solder it in with the other grounding wires from a different ecu pinout? (on one of the yellow plugs)
Lastly, if installing a wideband, can the factory narrow band 02 sensor be completely take out? (I'm using PFC) Or should I leave some wire at the ecu so I can still have a narrow band signal going into it.
Edit: I'm reading that the factory 02 sensor can be removed and "turned off" on the pfc.
Just for the ground, here is a pic. I know this blue plug isnt on the usdm wiring harness but regardless, it's the only one that isn't yellow.
Here is a pic of the ground wire and how it ends. There were a few junctions along the way but everything off there has been eliminated so it's basically this one wire ending here.
Can I simply de-pin this or should I solder it in with the other grounding wires from a different ecu pinout? (on one of the yellow plugs)
Lastly, if installing a wideband, can the factory narrow band 02 sensor be completely take out? (I'm using PFC) Or should I leave some wire at the ecu so I can still have a narrow band signal going into it.
Edit: I'm reading that the factory 02 sensor can be removed and "turned off" on the pfc.
Last edited by Mitchocalypse; 09-23-12 at 07:50 PM.
