70 Nova TCS Relay

[Mr70]

Was this Chevelle in Michigan?
Is it Astro blue?

[JRSully]

I took off the complete wiring harness from an untouched 70 L78 Nova, including the wiring gutter w/ TCS switch attached. It is attached with those exact plastic push rivets. Does an original TCS switch have "littlefuse" stamped on the cover.???

[RonNova396L34]

Rick,
I got my plugs sitting in front of me here as I type and they look exactly like those you posted a picture of. They were on my car when I bought it from the original owner but I figured somebody replaced the rivets at one time. Now I'm glad I hung onto them. Also Rick, I think they may be the same plugs that are used to hold the flap for the radiator to the radiator support on BB 70 Novas. It looks about the same size but I can't remember if the cars I've seen had ones like that with the line that runs across the center of it?? It could be one and the same thing!!

Sully,
The wording says "little fuse inc" at the bottom. There are two styles of this TCS if I remember correctly. The style shown in that picture is a different one than mine. Mine also has a date above and to the right of the little fuse inc wording.
Ron [img]/ubbthreads/images/icons/smile.gif[/img]

[Nova Research Project]

Ron,

I agree that the plug looks the same as on the BB radiator seal. The radiator seal plug is also the same plug that is used to hold the grille to bumper filler to the steel reinforcement on the Nova. The picture I sent you was of part number 9792217 (attached). The short one is the original off of my bumper filler. The long one is the newer version I bought in a bag of 25 or so several years ago.

The plug 3952914 was used on the 69 Nova filler. In the 70 Nova model year 9792217 replaced 3952914 in December 69 on the filler. 9792217 and 3943268 were both used on the 69 and 70 radiator seal back and forth.

9792217 was shown in the 69 Camaro AM possibly as a replacement for the inner fender seal staples, but was removed on July 2, 68. I wonder if this plug was used anywhere else on the Monte/Chevelle?

Despite the TCS relay going back and forth between the two part numbers, I find no reference to plugs to install it. I wonder if this was done on the line because it was easier than the rivets?

[Nova Research Project]

JRSully,

"LITTELFUSE" stamped on the cover is correct for the one like I posted. Any chance of a picture for the research project? Any idea of the date code from the trim tag on that L78 Nova? I am tracking VIN and Body tag info. It would also help track when they may have started using the plugs.

If anyone else runs across any Novas (68-72) in the boneyards, would you mind grabing the VIN and everything off of the trim tag. Pic's are cool too. [img]/ubbthreads/images/icons/grin.gif[/img]

Thanks,
Greg

[Nova Research Project]

Marlin,

Oh yeah, I also found some steel rivets instead of the aluminium ones above. I got a few extras.

Greg

[Belair62]

What does the TCS switch do ? here is a trans mounted TCS switch on e-bay TCS

[RonNova396L34]

Belair62,
The item on ebay get's mounted into your transmission. The TCS stuff I believe came into effect for the 70 models. There are 3 parts to this system. The 1st is mounted into the transmission, the 2nd get's mounted typically onto the firewall wiring gutter and the 3rd is mounted at the front of the intake just in front of the air cleaner. This system deals with vacuum. In order for the engine to receive maximum vacuum, the engine has to be warm and the transmission has to be in 4th gear for a 4 speed. That is the way I understand I works. It deals with the amount of vacuum that is allowed and in what gear. Apparantly a lot of people take the inside stuff out and then it acts as a vacuum canister all the time. Don't have to worry about 4th gear then.

I believe TCS means:Transmission Control Solenoid???
Ron [img]/ubbthreads/images/icons/grin.gif[/img]

[Mr70]

Bob you asked...
TCS=Transmission Controlled Spark.
New for 1970 cars and Series 10 Trucks.It was designed to provide Vacuum Spark Advance during Hi-gear operation only.
Elimination of Vacuum advance in all but the forward gears,greatly reduces exhaust emissions.
It consists of:
*A Vacuum Control valve mounted on the intake.
*A Transmission control switch mounted on the trans.
*A coolant temperature switch mounted on the passenger side of the head.
The item on the firewall is merely a relay.
During operation the valve controls the Vacuum Advance to the Distributor,in response to a signal from either switch.This also hurt Horsepower,so we all pitched it upon taking ownership of the new MuscleCar.

[RonNova396L34]

mr70
Thanks for the clarification on that. I was having a couple of brain farts on that. I knew about the temperature sending unit but forgot it in the post. I couldn't remember what the "S" stood for so I left the ?? I knew somebody would clarify that.
Ron [img]/ubbthreads/images/icons/grin.gif[/img] [img]/ubbthreads/images/icons/grin.gif[/img]