AC/Cig Lighter and Accessory Wiring Question

[DeBattista]

Putting a half apart 1972 C10 Factory Air Truck back together. I was wondering if someone might know where the open terminal on the backside of the orange AC harness is supposed to plug-in I was thinking of utilizing it as a constant 12 V source for a clock I added, however I didn’t want to use it if it already has a factory purpose does anyone know what plugs in there? I have taken some photos and apologize they were at night, but you see the terminal which has a connector on it has an open mail plug inside of it. I have scoured my diagrams and can’t seem to find it anywhere what might go to it.

[71CHEVYSHORTBED402]

My 1971 has factory AC. Perhaps this may help. I won't swear by the anti-dieseling wiring, because I didn't install one. But I believe it came factory with one. This is how I understand it - see Blower Motor Relay.

[DeBattista]

Amazing information, I definitely won’t be running that, so that just tells me I can steal that for a 12V positive source. I assume it’s also safe to say this is not a keyed 12V source as I assume the cigarette lighter always has power.

I would just test light it but the engine harness and front harness are not plugged in.

['68OrangeSunshine]

Originally Posted by DeBattista

Amazing information, I definitely won’t be running that, so that just tells me I can steal that for a 12V positive source. I assume it’s also safe to say this is not a keyed 12V source as I assume the cigarette lighter always has power.

I would just test light it but the engine harness and front harness are not plugged in.

Depending on what accessories you intend on running thru the Cigar Plug port, I would suggest an in-line Fuse Holder with a 10 or 15 Amp fuse.
A weak Positive plunger from some accessory plug [GPS, RADAR Detector, etc...] bent over on insertion and shorted across the Ground side of the plug barrel, and I had a big short/electrical fire under my dash. As soon as I smelled the ''blue smoke'' -- I pulled the Negative lead from my Battery. Later I had to cull out and replace a lot of charred wiring from other systems I had looped together in a bundle, trying to make the wiring runs under my dash look neater.
Cheap insurance.

[DeBattista]

Originally Posted by '68OrangeSunshine

Depending on what accessories you intend on running thru the Cigar Plug port, I would suggest an in-line Fuse Holder with a 10 or 15 Amp fuse.
A weak Positive plunger from some accessory plug [GPS, RADAR Detector, etc...] bent over on insertion and shorted across the Ground side of the plug barrel, and I had a big short/electrical fire under my dash. As soon as I smelled the ''blue smoke'' -- I pulled the Negative lead from my Battery. Later I had to cull out and replace a lot of charred wiring from other systems I had looped together in a bundle, trying to make the wiring runs under my dash look neater.
Cheap insurance.

Everything will have its own fuse I don’t play that just tap in with the same power game. I’ve seen too many cars melt. It’s gonna be clock I added in the dash and the radio which has its own inline fuse.

['68OrangeSunshine]

Originally Posted by DeBattista

Everything will have its own fuse I don’t play that just tap in with the same power game. I’ve seen too many cars melt. It’s gonna be clock I added in the dash and the radio which has its own inline fuse.

Good. You're on top of the game.

[DeBattista]

Does anyone know if they make a pigtail that plugs into that or the harness for the anti-dieseling to steal the connector from.

['68OrangeSunshine]

Mostly Anti Dieseling Solenoids are tied into 12 DC in the engine harness, like electric chokes. Never heard of powering one off a Cigar Plug -- if I understood your query.

[jaros44sr]

The ground on the cigar lighter is prone to fail, as I have ready times, when you pull voltage

['68OrangeSunshine]

Originally Posted by jaros44sr

The ground on the cigar lighter is prone to fail, as I have ready times, when you pull voltage

The Cigar Lighter Socket [recepticle] has two parts: an inner Barrel and an outer Sleeve. It is grounded by contact with the Dash assembly. The Sleeve screws onto the Barrel. If there is too much paint around the Cigar Lighter Hole an incomplete ground may occur. Or the Sleeve may not be on the Barrel tight enough. There are saw tooth edges on the end of the sleeve to cut into paint.

And Semper Fi to you.

[71CHEVYSHORTBED402]

Originally Posted by '68OrangeSunshine

Mostly Anti Dieseling Solenoids are tied into 12 DC in the engine harness, like electric chokes. Never heard of powering one off a Cigar Plug -- if I understood your query.

Perhaps to add some clarification, if not confusion. My 1971 with an A/C harness had at least some different colored wires than the OP. I installed a 1970 version A/C harness, eliminating the anti-dieseling.

My fuse box had, and still has what's shown in this image. However, the anti-dieseling harness was disconnected. The CIG apparatus takes the orange wire from the blower relay, as shown.

As for the anti-dieseling relay:

An anti-dieseling was not reinstalled into this rebuild. Therefore this information is incomplete, and was not tested for accuracy. The anti-dieseling relay was not wired per one wire diagram, though the diagram may be incorrect for a 1971.

The anti-dieseling relay mounts the dash panel’s bottom lip, located under the cigarette lighter. The relay’s three terminal connector was wired as.

• 12 AWG orange - this wire ran to the blower relay.
• 12 AWG pink - this wire connected to the fuse panel's IGN. UNFUSED terminal.
• 14 AWG dark green - this wire connected to the A/C switch.

['68OrangeSunshine]

Some systems are not present on my rigs, so I have no empirical knowledge of them:
TCS -- Transmission Controlled Spark.
NSS -- Neutral Safety Switch.
ADS -- Anti-Dieseling Solenoid.
I know basically what they do. But I don't have them, or need to hook them back up.

[70STOVEBOLT]

TCS is transmission controlled spark.

['68OrangeSunshine]

Originally Posted by 70STOVEBOLT

TCS is transmission controlled spark.

Thanks. Corrected now.