1970 TCS Relay

[Stan F.]

Hoping that someone with an early production 1970 Corvette can tell me where the TCS relay mounts.

The AIM shows the mounting for later production cars, but there are no holes (just the dimples denoting the location to drill) on my car and the TCS lead on the wiring harness isn't long enough to mount it there even if it was drilled at that location.

I'm guessing that the early cars may have had an alternate mounting point... My car has been apart for a few years and the memory is a bit fuzzy.

Any help would be appreciated.

Regards,

Stan Falenski

[Cary Lewis]

Re: 1970 TCS Relay

Stan it may not be the same but on my '74 454 it mounts between the carb and the distributor to one of the distributor bracket bolts, on a 350 it mounts on the passenger side of the intake next to the carb.Hope this helps.
Cary Lewis

[Gary S.]

Re: 1970 TCS Relay

Stan, I assume that you are talking about the actual relay (some have also called it the TCS timer) that mounts on the passenger side of the firewall and not the solenoid that mounts near the carb. Is that correct?

Gary

[Stan F.]

Re: 1970 TCS Relay

Gary,

Yes, this is the relay that mounts to the firewall in some manner... Not the solenoid that mounts to a stud on the intake manifold. I've got a pretty early 1970 (#00538) and am wondering if there was a different mounting location during early production since it is apparent that it doesn't mount in the AIM specified location.

Cary, thanks for the response. It sounds as though you are describing the solenoid rather than the relay. The relay for the 1970-1972 cars is firewall mounted.

Regards,

Stan

[Jim T.]

Re: 1970 TCS Relay

Stan where does the AIM specify the relay to be mounted?

[Dennis D.]

Re: 1970 TCS Relay

Mines on the driver side left of the wiper washer pump

[Dave S.]

Re: 1970 TCS Relay

Stan,
Like Dennis my 70 #14803 has the TCS relay(s) mounted on the drivers side outboard of the wiper motor. If I recall correctly there are 2 relays and they are mounted back to back onto the same bracket using the same screw. I think my 71 is the same as the 70.

[Jack H.]

Re: 1970 TCS Relay

"I think my 71 is the same as the 70."

No, '71 cars used a 1-year only CEC (Combined Emission Control) system. There were a pair of controling relays (3990842, reversing + 3990843, delay) and they mounted back-to-back on a steel L-bracket anchored to the firewall forward of the driver just to the left of the WSW motor. But, in 1970, the position occupied by the firewall L-bracket was occupied by the wiper door vac relay which was moved to the rear of the RH inner fender in '71.

The '70 TCS system used a single control relay, 3961573. On passenger cars, it was riveted to the plastic weatherstrip sealing the rear of the hood to the engine compartment. If memory serves, the TCS relay for Corvette was mounted sideways (connecting terminals pointing to the WSW motor) on the inner fender just to the left of the WSW motor.

[Dave S.]

Re: 1970 TCS Relay

Jack,
As usual your are "on target" and I should have looked at the car prior to responding. The 70 is much different than the 71. My 70 has the single "573" relay. It is mounted vertically on the firewall just a bit away from the wiper motor on the drivers side. The leads that plug into it are very close to the motor. One of the leads is actually bent to accomidate the plug in lead from interfering with the wiper motor itself. The relay is held in by 2 black dish head hex screws w/ integral washers. The screws go through a large oval dish shaped washer with "goop" around it and into something like a nut plate inside the firewall. (I can't see it). I hope I didn't confuse anyone to much.

[Stan F.]

Re: 1970 TCS Relay

Jack,

Your explanation sounds reasonable and explains why I didn't see any holes through the firewall in that location. The spacing on the relay bracket and the installation orientation that you suggest also looks about right.

I gather that the relay is no longer available? Seems that very few are any more.

I'll check that out this evening, but it sounds as though that is the answer to my question.

Regards,

Stan