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Camaro Research Group Discussion => Maintenance => Topic started by: SP4535 on January 13, 2023, 12:39:14 AM

Title: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: SP4535 on January 13, 2023, 12:39:14 AM
Hi all, have a 1968 convertible 396 RS/SS T400 auto with H shifter in console. My question is, the car is believed to have the original T400 which has a neutral safety switch inside, there is an orange wire on the connector of the trans that runs up to the firewall with a plug on the end - where does that go, is it supposed to go through the firewall and connect somewhere ?  All the manual indicates is relating to NSS at the bottom of the column, or only on the H-shifter which I have. Im starting to wonder if this car does not have the orig T400, in that maybe NSS internal to T400 came in later years and was not available in 1968 ?  Any help appreciated please, thanks. I did find an assembly manual UPC page that shows a V8/w automatic with a side terminal NSS on the trans but it does not show where the wire connects in the vehicle side. The UPC page shows the wire routing exactly where the wire is in my car and the wire/clip bolted to the trans bolt. Its a singe orange wire with protecting loom coming up from the trans NSS.
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: 169INDY on January 13, 2023, 01:30:46 AM
The Orange Wire  (Carb mounted Switched supplied+12VDC) down to the Driver side of the Trans is a Passing Gear internal solenoid that is part of the Valve body.

Your Neutral Safety switch will be a) Part of the steering column or b) Part of the console shifter assy for D55 cars.
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: SP4535 on January 14, 2023, 02:58:23 PM
169Indy - Thank you !!!!
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: 169INDY on January 14, 2023, 04:32:41 PM
Here is a Shot of the 68 (LOS) TH400 Kickdown electrical Harness (GM)
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: SP4535 on January 31, 2023, 12:46:23 AM
Thank you, that's exactly what I have.
You guys nailed it, thanks.
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: 169INDY on January 31, 2023, 02:25:28 AM
Cool, the Yellow Feed wire, piggy backs off the wiper Motor HOT +12vdc, thru the NO normally open contacts of the switch as activated by a throttle carb primaries blade shaft arm bolted paddle at or near WOT iaw AIM adjustment setting. The Switches were used on Many Chev Bodies and Trucks and can be harvested from Donor cars-trucks. Grooming an Factory harness is important since it is Very unique to the SS396 w/ TH400. i.e. Helps document the Difficult 68 Cars.
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: Kelley W King on January 31, 2023, 03:58:11 PM
Does 69 use the same or a similar setup? My 69 appears to be missing it,s kick down parts.
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: 169INDY on January 31, 2023, 04:22:14 PM
Yes: 3-SPD AUTO TRANS-CONTROL SW
AIM, 1969
UPC M40
A8/A9
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: Chuck-68-Cam on January 31, 2023, 10:55:37 PM
Does 69 use the same or a similar setup?

Assuming it's a TH400.
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: Kelley W King on February 01, 2023, 02:27:10 AM
Mine is a 400 big block SS. Definely is missing the switch and wiring.
Title: Re: Help - 1968 RS/SS 396 T400 w/H shifter - Neutral Safety Switch wiring question
Post by: x66 714 on February 01, 2023, 03:37:00 AM
Mine is a 400 big block SS. Definely is missing the switch and wiring.

Kelley. I sent you a PM...Joe