Help!! Transmission Wiring Harness!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1971ChevyTruck · 12-20-2007, 04:10 PM

I have a 350 motor and 350 turbo tranny. I traced all the wires in the engine wiring harness and I have a wire that leads to a transmission wiring harness I think. It is wire 18DG on the wiring diagram. It has a wire connector and the has a bunch more connectors and wires. Is this needed for a 350 turbo tranny??

krue · 12-20-2007, 04:27 PM

Shouldn't have any wires going to the tranny, at least my 70 didn't have.

cdowns · 12-20-2007, 04:36 PM

no those wires arent needed in fact they were normally disconnected at the dealer prior to delivery //its a half assed attempt at early emmissions theres 2relays on the firewall drivers side near steering column that were always disconnected then a sensor on the manifold and a wire going to tranny sort of in back of the shift linkage

1971ChevyTruck · 12-20-2007, 05:00 PM

Here is a diagram of the wire I am asking about...I circled the wire..its 18DG on the engine wiring harness

72 CustomCamper · 12-20-2007, 07:21 PM

They should plug into the rear light harness for the back up lights. The other end plugs into the Backup/Neutral Safety Switch at the bottom of the steering column...

Chuck

JimKshortstep4x4 · 12-21-2007, 12:19 AM

The two wires that you circled are for the backup lights on a floor shift four speed manual transmission, (light green and dark green wires).

If your TH 350 has a wire connected to it, (one wire) then it was part of an emissions system that was mentioned in a previous post.

Jim

12-20-2007, 04:10 PM	#1
1971ChevyTruck Registered User Join Date: Jan 2005 Location: Illinois Posts: 1,006	Help!! Transmission Wiring Harness!! I have a 350 motor and 350 turbo tranny. I traced all the wires in the engine wiring harness and I have a wire that leads to a transmission wiring harness I think. It is wire 18DG on the wiring diagram. It has a wire connector and the has a bunch more connectors and wires. Is this needed for a 350 turbo tranny??

12-20-2007, 04:27 PM	#2
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Help!! Transmission Wiring Harness!! Shouldn't have any wires going to the tranny, at least my 70 didn't have. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

12-20-2007, 04:36 PM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Help!! Transmission Wiring Harness!! no those wires arent needed in fact they were normally disconnected at the dealer prior to delivery //its a half assed attempt at early emmissions theres 2relays on the firewall drivers side near steering column that were always disconnected then a sensor on the manifold and a wire going to tranny sort of in back of the shift linkage __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

12-20-2007, 05:00 PM	#4
1971ChevyTruck Registered User Join Date: Jan 2005 Location: Illinois Posts: 1,006	Re: Help!! Transmission Wiring Harness!! Here is a diagram of the wire I am asking about...I circled the wire..its 18DG on the engine wiring harness Attached Images

12-20-2007, 07:21 PM	#5
72 CustomCamper huh ??? Join Date: Nov 2002 Location: Fredericksburg,Va. Posts: 3,369	Re: Help!! Transmission Wiring Harness!! They should plug into the rear light harness for the back up lights. The other end plugs into the Backup/Neutral Safety Switch at the bottom of the steering column... Chuck __________________ 90 Blazer Silverado 350w/ 700R4 and 32" Kelly's "I am a bomb technician. If you see me running try to keep up!"

12-21-2007, 12:19 AM	#6
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Help!! Transmission Wiring Harness!! The two wires that you circled are for the backup lights on a floor shift four speed manual transmission, (light green and dark green wires). If your TH 350 has a wire connected to it, (one wire) then it was part of an emissions system that was mentioned in a previous post. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC



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