FinallyGotIt

Need some help. I am 99% sure my TCS Solenoid is missing in my 1970 Cutlass Supreme Convertible Rocket 350. I was troubleshooting why my reverse lights were not working, service manual states to use a trouble light on the TCS solenoid. Ok, and.....its not there. We found the one vacuum hose coming off the air filter not connected to anything, and think we found one of the dark green wires coming up from the tranny. So, if I spend $$$$ on a new solenoid, and it does not work nor help with the reverse lights (which are not burned out), then what. And my car runs pretty good, a little sluggish at times, a little slow to shift from 2 to 3, but.......Thoughts??

m371961

I thought the reverse lights were controlled by the neutral safety switch, not the TCS. I am not a cutlass guy, but that is how the rest work.

vette442

If it turns out that you need one, I just got a really nice used 1970 TCS solenoid for my '70 SX (mine was long gone too) from Nick Zripko (442crzy) on here. Pretty sure he had more of them.
Terry

Fun71

You are correct, the reverse lights are controlled by the neutral safety switch. Is this a floor shift or column shift car?

The TCS is an emission control device and has nothing to do with the reverse lights.

FinallyGotIt

Ok. Let me take a relook. Thanks for the direction. BUT......should I go to the expense of putting the TCS solenoid back. It was clearly bypassed as the vacuum hose now goes directly into the carburetor. Worth the $200 invest to see if it makes a difference? And then I have to try to relook it to the tranny, which may lead to needing to replace the switch there. I guess I am looking for someone with more experience with these items who can say "OMG, yes. Well worth it. I did it an immediately noticed a difference. yada yada...Thanks.

joe_padavano

Let's ask the right question: Does the car still have the backdrive linkage from the trans to the steering column?

joe_padavano

Huh? Where? I've got the 1970 CSM open in front of me. Nowhere do I find anything that directs you to the TCS to check the reverse lights.

Fun71

The TCS is an emission control device that is part of a system that allows vacuum advance only when the engine is up to temperature and the transmission is in high gear.

So the answer to some of your questions are:
A) No, it's not worth $200 to experiment and see if it makes the transmission shift correctly (it won't).
B) Yes, you may immediately notice a difference (but not in a good way - it will likely DECREASE performance. This is likely why the previous owner removed/bypassed it).

Koda

TCS is junk leave it bypassed.

FinallyGotIt

Thanks. I will review my steps again on the reverse lights and see where I went wrong

joe_padavano

The reverse light circuit is pretty basic. Power from the ignition switch feeds the TURN SIG - BACK UP fuse (hint: if the turn signals work, this fuse is good). From there a green/white wire runs to the backup light switch and a light green wire runs from the switch to the backup light housings at the bumper. I don't understand how you got the TCS involved in that.

FinallyGotIt

Update folks. First, thanks for all the help. I am a novice at this, and have my 19 year old helping me.
1. On the diagram in the CSM, If you follow the reverse line back from the rear it goes to the neutral safety switch, and then to the fuse box. But, before it enters the fuse box, it appears to merge with another line, same color and style, and that line goes to the TCS. So that is how my son thought there would be related. If that is simply a product of how a line diagram was drawn in 1970, ok.
2. I followed the CSM for troubleshooting the neutral safety switch. It says to try and start the car in drive, and slowly move the gear shift (mine is on the floor) to neutral. At some point, it should start to crank and start. MINE ATTEMPTS TO START WHILE IT IS IN DRIVE! The car did not move, but I quickly stop turning it over at that point. I did not attempt to do the same in reverse. So I am thinking the neutral safety switch is bad.

Thoughts at this point. And again, thanks.

matt69olds

Fun71

FinallyGotIt

Hey guys. Update 2: I bought a new neutral safety switch. The switch itself now does as intended. It starts only in drive and neutral (although the switch does need to be adjusted north-south a bit). But my reverse lights still will not work. So, I jumped from the green out at the switch, directly to the battery, and voila, the reverse lights light up. I also put a voltage meter on the output from the switch and could not get any voltage at all even with the car running, even with it in reverse, and moving the gear shift a little north and south. So the new switch I bought is defective??

FinallyGotIt

Well, the close out this thread. I got a replacement of the replacement neutral safety switch (vendor sent me another), and......IT WORKED. And my reverse lights work. Thanks to all who helped point me in the right direction. The entire interior of my car except the dash is out...and on to the next project.

VC455

First off, congratulations, you are far ahead of the rest of the pack just because you use the CSM and look at the wiring diagram.

Now to the statement you made, quoted above: When looking at a component in the wiring diagram, locate the source of the current (battery positive side) and the location of the ground. Trace forward from the source toward the ground. If you do that in the case you referenced, you would trace out of the fuse box. You then get to a splice that feeds the TCS and the reverse lights. So you would ignore the TCS, as it is merely another place where the current on this circuit goes. You would continue to trace forward toward the reverse circuit.

v8al

Yeah, the TCS zapped me once with reverse lights. The fuse for the reverse light kept blowing. Couldn't figure it out. Referenced to the wiring diagram and noticed that the TCS was in the same circuit for +12 volts. Sure enough the TCS had been disconnected by a prior owner and the TCS plug was grounding on the intake manifold.

FinallyGotIt

Thanks VC455. I get what you are saying about simply another place on the current line - makes sense, and a nice thing to keep in mind for future. v8al, believe me, the key to the whole car running is grounding!!! The NSS, the clock!!!. The fact all the power/ground to the entire car goes through the horn relay - disconnect the red wire...poof, no power- is amazing to me. When in doubt, think grounding or look for something that is grounded that should not be. Thanks all.