Hey guys, been learning alot from all the past posts here. Thanks to all who've contributed. Have, what I guess is an early 77, can't get any info. for the VIN but that's not the problem at hand, any help on that would be great though.

Been cleaning up the wiring from previous owners in the engine bay and have seen extra wire going to the oil pressure sensor? and the water temp. sensor? both sensors in the engine block. These wires were excessively long and wrapped/looped and taped outside the split wiring flex tubing that contain most of the wiring from both harness leads from the firewall. These wires were up to 2 to 3 feet longer than needed. In order to clean it all up I cut both wires, to shorten them, and reduced the splice to one solid one instead of the 3 to 4 twisted splices only held together by electrical tape. Yeah it's amazing that car was running but I've seen back yard mechanics make things work before, but not for long.

What I need to know is if those wires were factory for some type of resistance for the gauges. It appeared strange that the extra wire in question was maybe a resistance wire because it was single strand silver color as opposed to the multi strand copper from the factory harness. Car has the original gauges so I don't know what's going on till I start the car and run it, in the near future hopefully but I need to see if it's overheating and/or has low oil pressure before I run it too long. Thanks to all in advance.

 

I own a early 77. I've had mine since Christ was a Corporal. No wiring on these cars were resistant wires. Resistance equals problems with these old cars. Normal copper wire was used throughout.
I can supply copys from the Electrical Trouble Shooting Manual. But it sounds like you should find a copy for yourself.
look for a genuine G.M. Electrical Trouble Shooting Manual for a 77 Corvette. Explains every circuit and breaks it down circuit by circuit. Worth its weight!

 

"IF" your car is a Automatic
And
"IF" one of the wires your talking about is Brown with a White tracer it is possible your car may have had cruise control as an option...
It may also be just a solid Brown wire, Troubleshooting manual says Brown/Wht...
"IF" so, that Brown/Wht wire "IS" a resistance wire and very long...
It was part of the cruise harness and made many loops length wise around the vacuum line from transducer & servo through firewall to vacuum break switch near brake light switch...
See this pile of Brown Wire? This is a resistance wire from another members 1977 Cruise circuit....https://cimg5.ibsrv.net/gimg/www.cor...afc17a4a5e.jpg

 

Car is automatic w/cruise control but that's not the wiring I'm referring to. I'm disabling the cruise control for now and removing that vacuum line and wiring. Hope that doesn't give me an issue with the speedo. Thanks.

 

I'll definitely look for that manual, didn't know there was one specific to electrical. Whoever had this car before me really did a sorry azz job when they worked on it. Thanks for the advice.

 

As long as you keep the transducer in-place no problem with speedometer.
If you remove the transducer you will need a new cable long enough from trans to speedo...

 

I intend to leave the transducer. Sounds like you're up on the knowledge so I'll ask another question. Getting rid of all the emissions junk on this car. Headers and no catalytic. If I cap off the fuel vapor canister port that went to the vacuum but leave the line to the gas tank do you think I'll have any problems there? I know I'm rushing things by not removing the canister but I intend to blow this engine up, after having a lot of fun, then when I have the engine pulled for rebuild I'll get to the clean up of the engine bay and install the headers.

 

Cap off the vacuum. Then disconnect the hose from the tank to the canister. Just let it vent to the atmosphere. I like to have it pointing downward so any moisture can drain out.