Wire gauge for wires going to PCM

pcrawfordpt

pcrawfordpt

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Feb 15, 2021
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Big Bear City, CA.
Found my PCM and wiring harness were damaged from battery tie down bracket. Throwing code P0505…thinking one of these wires controls my IAC. Getting voltage to IAC, but only 10.39…spec is 10.5-12. Need to splice in some new wire to see if that resolves the issue. However I am not sure what gauge wire to splice in. Does anyone know the gauge?

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pcrawfordpt said:
Found my PCM and wiring harness were damaged from battery tie down bracket. Throwing code P0505…thinking one of these wires controls my IAC. Getting voltage to IAC, but only 10.39…spec is 10.5-12. Need to splice in some new wire to see if that resolves the issue. However I am not sure what gauge wire to splice in. Does anyone know the gauge?

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The FSM for every year is posted on one of the other subforms, it gives great detail for what gauge every wire in the harness is. If you feel like being "more correct" you can order lengths of wire with custom colors & traces. They don't look like the factory wires but white with purple trace is still white with a purple trace even if it's not indistinguishable from the factory wiring. But if you have to replace a long run it might aid troubleshooting down the road.

https://4rcustomswire.com
 
Thanks everyone. I did try to searching for it in the FSM PDF’s here, but couldn’t find it. I don’t think I need to order exact wire colors as I’ll only be replacing a short section and the original wire colors can easily be seen/found. Just wanted to use the correct gauge wire.
 
UPDATE: I spliced in new wires, but unfortunately nothing changed...still throwing code P0505. Still getting 10.3 volts at IAC. I think there must have been a short with the exposed wires, causing a malfunction with my PCM.

Wires exposed, frayed and spliced:
Brown/Light Blue - A6, P/N Position Sensor
Light Green/Black - B12, Injector #6 Driver
Pink/Black - B6, Injector #5 Driver

Wires Exposed, but appeared to only have plastic coating rubbed off, and exposed wire was taped:
White/Orange - B27, Vehicle Speed Sensor
Gray/Yellow - B23, Oil Pressure Sensor
White/Dark Blue - B4, Injector #1

Since the PCM's aluminum casing was also damaged (see attached) from rubbing the battery tie down, I think that either that or a short has damaged the PCM? Note the damaged PCM casing has been like that for over a year. Noticed it and re-secured it, however only recently noticed the frayed wires from rubbing the battery and tie down. Check yours!

Any thought before I order a new PCM?

Thank you!

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#1 thought is only order a new PCM from @Wranglerfix over any other company selling them.

The only other thought I have is to check your grounds to see if that's why the voltage drop is only 10.3V instead of 12 & change. I don't know where the IAC ground comes from off the top of my head, but it's worth checking out. And don't assume that the wires you addressed are the only problematic ones in the harness. 25 years has a way of not being kind.
 
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