Melting System Ground Wire!

DWCaprice2017 said:

Hi, Everyone!
I have an '84 Caprice with a 305.
For months, I've not driven the car except to move it for street-cleaning days due to smelling burning plastic, and seeing a whisp of smoke coming from the rear of the engine once the engine warmed up--but I couldn't locate the source. Yesterday, as I looked at how much stuff I'd need to pull off to remove the left valve cover (to replace the slowly seeping gasket), I saw that the two Ground System wires at the rear of the engine were bare--the insulation had melted--this must have been the cause of the burning smell and smoke. I found a small piece of wiring loom around the wires, I figure the loom eventually deteriorated, letting the wires touch the block. The bolt that the wires attach to, I guess on the bell housing (near the trans dipstick tube), is nearly impossible to get at, so I figure I'd just splice in new wire and attach it onto a ring terminal, securing that on an easier engine bolt, maybe on a bracket.
How does this sound?

Also, as I'm intending to keep the car for awhile--getting it almost five years ago--I'm trying to find detailed diagrams of the wire routing--not the nearly indecipherable schematics in the rear of the 1984 Chevrolet Shop Manual ST-329-54 that I got from a CD-Rom, there's no drawing of the rear of the engine where the System Ground wires attach, for example.
In the attached photos, I'm using a pencil eraser to point.

Click to expand...

DWCaprice2017 said:

scoti, ELCAM, 383_StealthRam, Ernest,
Thank you all for your responses!
I tried to clean that bolt where the wires attach--not easy to do. I tried scratching off
dirt with a screwdriver, nothing came off, after I used engine degreaser spray.

I didn't see any signs of a critter having nibbled the wires.

The electric choke wire goes to another area.
--------------------------------------
What I hadn't said in my original post is that the engine has
an electronic QuadraJet, and that I live in California--the car
may have different emission parts in 1984.

I have a new mystery--I'll post this on the main page also.
The first photo below is the EGR valve. In all of my searching, I've not seen any replacement EGR valve
that looks like this--with two vacuum ports. Is this OEM for the car? As can be seen in the second
photo, there's a hex screw that apparently holds the EGR onto the base.

When I removed the hose from what I think is the exhaust gas recirculation solenoid valve that connects
to the EGR valve (see engine photo), a little carbon came out of the hose. I've been trying to find a replacement
EGR solenoid, figuring that it might be full of carbon, but I can't find the part.

I did discover that the hose that connects to the side tube of the EGR valve was poorly fitting, surely
causing a vacuum leak--likely all of the hoses need to be replaced!

With the EGR Valve off the engine, I'm taking it to a mechanic to use a hand vacuum pump on
it to see if the diaphragm is still good. I'll likely replace the EGR valve anyway, which brand is
recommended?

Thank you for the help!
Bye,
Daniel

Click to expand...

DWCaprice2017 said:

Hi, Everyone!
I have an '84 Caprice with a 305.
For months, I've not driven the car except to move it for street-cleaning days due to smelling burning plastic, and seeing a whisp of smoke coming from the rear of the engine once the engine warmed up--but I couldn't locate the source. Yesterday, as I looked at how much stuff I'd need to pull off to remove the left valve cover (to replace the slowly seeping gasket), I saw that the two Ground System wires at the rear of the engine were bare--the insulation had melted--this must have been the cause of the burning smell and smoke. I found a small piece of wiring loom around the wires, I figure the loom eventually deteriorated, letting the wires touch the block. The bolt that the wires attach to, I guess on the bell housing (near the trans dipstick tube), is nearly impossible to get at, so I figure I'd just splice in new wire and attach it onto a ring terminal, securing that on an easier engine bolt, maybe on a bracket.
How does this sound?

Also, as I'm intending to keep the car for awhile--getting it almost five years ago--I'm trying to find detailed diagrams of the wire routing--not the nearly indecipherable schematics in the rear of the 1984 Chevrolet Shop Manual ST-329-54 that I got from a CD-Rom, there's no drawing of the rear of the engine where the System Ground wires attach, for example.
In the attached photos, I'm using a pencil eraser to point.

Click to expand...