Transmission connection wiring differences - Truck vs F-body

[turbo_bu]

I'm doing a stand alone swap of an 2001 5.3 / 4L60E out of a Silverado. Reviewing the differences between truck and F-body 4L60E transmission connections, it appears that the truck transmission uses two Park/ Neutral Posisition Switches while the F-body does not. Along these same lines, the F-body, I have read only requires 1 ground wire to indicate that the car is in Park/Neutral (C1 (blue) 34). What has me a little bit puzzled, is why does the truck need the extra wires. Looking at the connector listing (I only have a copy of the pin out - no schematic) ... the 2 PNP switches for the truck show things like

- Transmission Position Switch Signal (A, B, C and P)
- Netural Safety Switch Park Signal
- Back-up Lamp Supply Voltage
- Neutral Saftery Switch Park/Neutral

Some questions that I started to ponder ....
- So for a truck OS, these connectors are used to trigger the back up lights while in reverse? Would guess through the BCM?
- is this the park / netural safety switch for starting?

Reason for asking is that I am considering using the F-body OS. I have documented the pin out differences for the PCM, just not quite sure about how things will operate. If you happen to have a schematic of the transmission, back up lights, or starting circuits that you could share that would be great. It would be nice if these connectors could be used as is for the back up lights and neutral/park saftey switch.

Thanks,
Darren

[minytrker]

The transmissions are interchangeable you just have to change the shifter lingage and for trucks add the block box to the shifter linkage that does shifter postion and neutral safety. On trucks they get there gear selector postion and neutral safety from a box on the side of the transmission. On F bodies they get there neutral safety and gear postion form the actual shifter in the car. You do have to drop the pan to change out the shifter linkage coming out the side of the trans if you need to change from truck to f body or vise versa.

[turbo_bu]

minytrker

Thanks for the reply. This is what I was thinking was the case, but didn't have the schematics to prove it. For this swap, I'm not sure which shifter we will be using, so having the "option" of using the truck black box on the transmission might make it easier to setup the backup lights. As you said, most shifters already have the neutral safety switch built in.

[EagleMark]

I just went through this F body to Truck harness. This thread may help and has a wiring .pdf from Mr Prick which really helps explain wiring and issues between harness and car to truck OS.

http://forum.efilive.com/showthread.php?21275-Wiring-differences-truck-to-F-body-PCM

[turbo_bu]

EagleMark,

yeah, I saw your thread and compared the pinouts that Mr. P posted. They were both helpful to confirm what I was seeing. The issue that I couldn't quite figure out was how these circuits were setup (needed a schematic to help me understand instead of a pinout).

[EagleMark]

If you PM your email I can send you a Zipped folder with 2001 truck schematics.

But I think everything you need is at http://www.lt1swap.com/

[mr.prick]

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