Neutral/Park Switch signal to ECM - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Mrrilla · 05-03-2010, 03:31 PM

I swappped TPI motor into my truck and everything runs good except I didn't hookup the orange/black (B10) wire that tells the ECM that the truck is esseciatley in drive. The idle RPM could be a little higher when in gear.

I believe the ECM can get this "ground" signal from the Neutral Safety switch except the unit that is in my truck is 4 prong (2 ignition, 2reverse).

I was thinking that maybe I could install a later model truck TBI NSS or something like that. So to everyone that swapped in an EFI motor, how did you send this signal to the ECM?

Attached is a picture of my current NSS

Mrrilla · 05-04-2010, 09:45 AM

I found a solution and I thought I'd post my findings for anyone else.

Painless 60122 park/neutral relay kit solves this problem but its about $67. You can also make your own which is what I did. All the parts are available at radio shack and it cost me about $12. Now when going into drive the RPM jumps 75 RPM just like I had planned.

I looked at installing a Neutral safety switch from a 1990 chevy 1500 TBI which also would have worked but the mounted scheme was a bit different.

In my opinion hooking this B10 signal up is important. I know some guys just ground it all the time which is fine but your idle jumps a bit more when in Park or Neutral.

rchavez101 · 10-15-2011, 09:36 PM

I know this is an old post but would this only apply if you have an electronic transmission in your truck? I recently coverted my 94 chevy truck from manual to a Turbo400. When the truck is in gear and you are holding the brake there is a vibration to the truck. If I hold the brake while in gear and give it a little bit of throttle the vibration seems to go away. I contacted a company that programs the chips and he said he could program the chip so that the truck knows it has a auto instead of an automatic. I did tell him it was a turbo 400 so he said I would need to wire in a neutral/park safety switch so the ECM knows that the truck is in gear other then park and neutral. Any thoughts from anyone on this issue?

rchavez101 · 10-15-2011, 09:38 PM

This is the kit needed to do the wiring or you can do what Mrrilla said above with parts from Radio Shack.
http://www.painlesswiring.com/webcat...rchField=60122

05-03-2010, 03:31 PM	#1
Mrrilla Registered User Join Date: Feb 2007 Location: Tucson,AZ Posts: 66	Neutral/Park Switch signal to ECM I swappped TPI motor into my truck and everything runs good except I didn't hookup the orange/black (B10) wire that tells the ECM that the truck is esseciatley in drive. The idle RPM could be a little higher when in gear. I believe the ECM can get this "ground" signal from the Neutral Safety switch except the unit that is in my truck is 4 prong (2 ignition, 2reverse). I was thinking that maybe I could install a later model truck TBI NSS or something like that. So to everyone that swapped in an EFI motor, how did you send this signal to the ECM? Attached is a picture of my current NSS Attached Images __________________ 1970 C10 SWB, 67 front clip, 3/5 drop, 350 TPI/700R4, Fiberglass tonneau cover, lots of body mods and.....a ford seat

05-04-2010, 09:45 AM	#2
Mrrilla Registered User Join Date: Feb 2007 Location: Tucson,AZ Posts: 66	Re: Neutral/Park Switch signal to ECM I found a solution and I thought I'd post my findings for anyone else. Painless 60122 park/neutral relay kit solves this problem but its about $67. You can also make your own which is what I did. All the parts are available at radio shack and it cost me about $12. Now when going into drive the RPM jumps 75 RPM just like I had planned. I looked at installing a Neutral safety switch from a 1990 chevy 1500 TBI which also would have worked but the mounted scheme was a bit different. In my opinion hooking this B10 signal up is important. I know some guys just ground it all the time which is fine but your idle jumps a bit more when in Park or Neutral. Attached Images __________________ 1970 C10 SWB, 67 front clip, 3/5 drop, 350 TPI/700R4, Fiberglass tonneau cover, lots of body mods and.....a ford seat

10-15-2011, 09:36 PM	#3
rchavez101 Registered User Join Date: Jun 2011 Location: Rio Rancho NM Posts: 503	Re: Neutral/Park Switch signal to ECM I know this is an old post but would this only apply if you have an electronic transmission in your truck? I recently coverted my 94 chevy truck from manual to a Turbo400. When the truck is in gear and you are holding the brake there is a vibration to the truck. If I hold the brake while in gear and give it a little bit of throttle the vibration seems to go away. I contacted a company that programs the chips and he said he could program the chip so that the truck knows it has a auto instead of an automatic. I did tell him it was a turbo 400 so he said I would need to wire in a neutral/park safety switch so the ECM knows that the truck is in gear other then park and neutral. Any thoughts from anyone on this issue? __________________ 94 Chevy SWB in progress. http://67-72chevytrucks.com/vboard/s...d.php?t=477390

10-15-2011, 09:38 PM	#4
rchavez101 Registered User Join Date: Jun 2011 Location: Rio Rancho NM Posts: 503	Re: Neutral/Park Switch signal to ECM This is the kit needed to do the wiring or you can do what Mrrilla said above with parts from Radio Shack. http://www.painlesswiring.com/webcat...rchField=60122 __________________ 94 Chevy SWB in progress. http://67-72chevytrucks.com/vboard/s...d.php?t=477390



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