ok im doing a 3800SC swap from a 97 Riviera with 4t65e -hd trans into my 87 fiero base coupe. I downloaded the files for the wire pinout harness thing and im wiring up my harness. on my range selector switch I have a 7 pin plug and I can wire all that up no problem...but it has a 4 plug also to the left of it what do I do with that?

I " believe" that is the neutral safety switch. That has to be wired in also. (unless you wire it like it's a "Stick", they didn't come as "stick" so I don't even know IF you can.

The seven pin should be neutral start and reverse lights switch the four pin is to tell the PCM which gear you have selected and the four wires go to the PCM. Should be a white, grey, yellow and black with white. Also remember to make sure the black wire from the seven pin plug is grounded as it works with the four pin one

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DARN Cars now open with
Over 30 years wiring experience between cars and trade as an avionics technician in both Canadian Air Force and civilian aviation.
Over 25 years experience building and modifying cars.
Over 10 years of full Fiero engine swaps and harnesses building and still going.

yelp those are the colors I just don't see where on the pcm they go ill recheck the pin out from the the file I downloaded hmmm I wonder if I can splice from it and and an led on my dash to show the gear im in? has anyone down this ? Im really thankful for the response.

Only the four from the 4 pin plug go to the PCM. The large wires on the 7 pin are the starter switch neutral lock out. Black on the 7 pin goes to ground. The remaining two are the reverse light switch. Follow the directions on http://gmtuners.com to see which each of these wires go.

Sometimes, wiring diagrams list those as transmission parity switch. Diagram may show 3 wires as 1 is select/switch ground. Also if not working PCM will give an error code.

ive looked I cant find where the 4 small wires go to my pcm I got the pinout file from gm tuners I don't see what pin it is...am I overlooking something?