71 blazer - green ground wire

[blazintowers]

hello everyone,
wanted to know if anyone knows where this green ground wire is supposed to be terminated? it comes from the harness behind the distributor and is long enough to route to the front of the motor? I know I could probably ground anywhere but does anyone know what its for?


71 blazer

ac equipped

[blazintowers]

sorry for the sideways pics, I swear they were correctly oriented before I attached them!

[Wrenchbender Ret]

I don't think it is a ground wire. It probably goes to a temperature sending unit or possible compressor clutch.
George

[blazintowers]

Thanks for the reply Wrenchbender. I thought it was a ground due to the wire being crimped to that metal tab. I will trace it out and see where the other end terminates at to see if it goes to a circuit.

Todd

[rpmerf]

Agree with temp sender. My temp sender wire has the same bracket on it.

http://outintheshop.com/faq/wiring/w...s/image002.jpg
20DG in the schematic

[blazintowers]

hello rpmerf, you don't happen to have a pic of the bracket connected to your sensor do yah? I just looked at mine again and found another green wire that is used for my temp sensor so I am even more confused...Also the wiring diagram you attached is different than the one I have. Do you know if there are different wiring diagrams for trucks and blazers? I wouldn't think so but mine is definitely different and it is from the original service manual.

[blazintowers]

here is the diagram I have, not sure if I am using the correct one but it matches my blazer wiring. notice the relays I have circled . now I also notice two dark green wires running to two different sensors, one HOT and one COLD.
Does any one know what the "SW ASM" stands for in the "ENG TEMP SW ASM COLD"?

EDIT:
Ok, thanks for the info, looks like circuit 35 and 159C for two separate sensors

[rpmerf]

I don't. When I got the truck, the wire was running down the frame rail and the bracket was not connected. Currently have it going over the valve cover. I think it originally gets bolted to the block, kind of following the spark plug wires under the exhaust. Just a guess though.

[VetteVet]

Here is a possibility. you might want to do some research on the TCS, aka- transmission controlled spark.

http://67-72chevytrucks.com/vboard/s...ntrolled+spark

[Wrenchbender Ret]

Some vehicles back then had a hot light & cold light. The sensor had 2 terms. One wire was dark green & the other was a light green. The cold light would go out when the temp. of the engine started to warm up. There was no use turning on the heater until the green light went out
George

[blazintowers]

thanks for the replies and great information everyone! I can see now that they do run to the two sensors - hot and cold, via circuits 35 and 159c.

Where do you find all the codes for the abbreviations? looking for what SW ASM stands for, its on the wire diagram above.

[Wrenchbender Ret]

The ASM is a switch that only allows the vacuum advance to work in high gear with an auto trans. It is an early emission control device & is best left bypassed.

[blazintowers]

Originally Posted by Wrenchbender Ret

The ASM is a switch that only allows the vacuum advance to work in high gear with an auto trans. It is an early emission control device & is best left bypassed.

So when you say bypassed, do you typically leave the original parts in place and just disconnect them, or remove the stuff you don't need to clean up the engine bay? I'm doing the HEI wire to replace the resistor wire and trying to tidy up a bit...Thanks ALL again !