1970 engine wire

[Richard H.]

Hi,

I am working on a 1970 coupe 350/350 4 speed with A/C. It has all available options except tilt and telescopic.

I need help identifing a wire and were it goes in the engine compartment. The wire comes out of the harness from under the wiper motor. There are two wires, one wire is light blue and the other is black and they are wrapped together heading towards the ac unit on the passenger side of the engine. Hoping someone can help out.

Thanks,
Rich Harris

[Richard M.]

Re: 1970 engine wire

What terminal types are on the ends of the 2 wires?

This may help.....

1970 Wiring Diagram


I see black and light blue going to the wiper motor, and also the windshield wiper relay & solenoid, page 2 of the diagram, upper left quadrant. I do not know where the relay & solenoid are mounted.

Rich
edit......that's funny, 1,970 posts at this point for a 1970 Corvette!

[Dennis D.]

Re: 1970 engine wire

Could this be it? My 70 350-350 non A/C.....

[Mike G.]

Re: 1970 engine wire

What terminal types are on the ends of the 2 wires?

This may help.....

1970 Wiring Diagram


I see black and light blue going to the wiper motor, and also the windshield wiper relay & solenoid, page 2 of the diagram, upper left quadrant. I do not know where the relay & solenoid are mounted.

Rich
edit......that's funny, 1,970 posts at this point for a 1970 Corvette!

you should play those numbers in the lotto

[Richard M.]

Re: 1970 engine wire

Could this be it? My 70 350-350 non A/C.....

What is that? Looks like a vacuum hose connects to it somewhere. Something for emissions?

Whatever it is I bet that's where the wires go. Rich said light blue, yours seems dark blue, but I'd bet engine heat faded the blue on his.

Rich

[Dennis D.]

Re: 1970 engine wire

What is that? Looks like a vacuum hose connects to it somewhere. Something for emissions?

Whatever it is I bet that's where the wires go. Rich said light blue, yours seems dark blue, but I'd bet engine heat faded the blue on his.

Rich

Connector for the TCS solenoid. I have the front vacuum line bypassed to get full time advance. It IS a light blue wire. May come accross darker in the pic. Also locates on the AC compressor side.

pic courtesy Stan Falenski

[Joe L.]

Re: 1970 engine wire

Hi,

I am working on a 1970 coupe 350/350 4 speed with A/C. It has all available options except tilt and telescopic.

I need help identifing a wire and were it goes in the engine compartment. The wire comes out of the harness from under the wiper motor. There are two wires, one wire is light blue and the other is black and they are wrapped together heading towards the ac unit on the passenger side of the engine. Hoping someone can help out.

Thanks,
Rich Harris

Rich------


Many of these TCS solenoids were removed many years ago by owners wanting to improve driveability and fuel economy. Nobody in their right minds (save for restorers who are usually not in their right minds, anyway) would want one of these things in functional condition. Some emission control systems unnecessarily get a "bad rap" but this TCS system is not one of those. It's deservedly despised.

Did someone cut off the connector from the wires?

[James B.]

Re: 1970 engine wire

Dennis,

What specific method did you use to bypass the front vacuum line?


James

Connector for the TCS solenoid. I have the front vacuum line bypassed to get full time advance. It IS a light blue wire. May come accross darker in the pic. Also locates on the AC compressor side.

pic courtesy Stan Falenski

[Bill C.]

Re: 1970 engine wire

Dennis,

I think you have your front and rear hoses connected wrong.

The port on the front of the carb is ported vacuum and should be connected to the other side of the solenoid.
The hose that is connected to the rear of the carb (i'm pretty sure) is just opened to the atmosphere (no vac).

On the solenoid - the atmoshpere connection is in the front where the wire connects, it should have a small square foam block glued and covering the nipple. The vacuum source gets connected on the side that has the two hose connnection.

I'm 99% sure - but not 100% - so hopefuly some others will chime in.....

[Jim T.]

Re: 1970 engine wire

Rich------


Many of these TCS solenoids were removed many years ago by owners wanting to improve driveability and fuel economy. Nobody in their right minds (save for restorers who are usually not in their right minds, anyway) would want one of these things in functional condition. Some emission control systems unnecessarily get a "bad rap" but this TCS system is not one of those. It's deservedly despised.

Did someone cut off the connector from the wires?

I bought my 1970 new on 8/18/1970. I ordered from Helm Inc. and received my new GM 1970 Chevrolet chassis service manual in September 1970. The manual actually covered other 1970 Chevrolet cars but showed 1969 Corvette at the bottom of the front cover. After reading my owners manual and the service manual about TCS and what it does I stopped using it and converted to 100% full time vacuum with a longer vacuum hose. My TCS solenoid is still mounted to the intake unused.
What brought my attention to the TCS function was a hot day in September 1970 I left my 70 running while out of the car and the air conditioning was being used. I was out of the car long enough for the engine temperature to get high enough to make the TCS send full time vacuum to help reduce the increased engine temperature. The sudden increase in engine RPM got my attention and I was unaware of the actual TCS functions. Did not want my 70's TCS functional after this experience. Better gas mileage in city driving and lower engine temperature in city stop and go driving without TCS control.

[Dennis D.]

Re: 1970 engine wire

I simply rum a direct line from the front port of the carb, (Bill that is the correct configuration), to the distributor as my first photo shows and leave evrything else connected as Jim mentioned.

[Richard H.]

Re: 1970 engine wire

Dennis,

Great picture, that is the wire.

Thanks,
Rich

Could this be it? My 70 350-350 non A/C.....