Burned wire

[J54 Mark]

On my '94 6.5td -

While doing a starter motor rebuild, I discovered a very badly burned green wire running from the front of the engine, below the head, but above the starter. It runs back to the firewall area where it disappears above the transmission.

This wire crumbled when touched. Every time I grabbed a piece, it simply disintedgrated.

Not, perhaps, coincidently, I am now getting rather a lot of smoke when starting in the cold until the engine warms fully.

Anyone have any ideas on this at all?

Mark

[DmaxMaverick]

Glow plug wire. Get 'em clear of the exhaust and insulate them! That also explains your smoke.

[Barry Nave]

This is also a one of a kind wire

[J54 Mark]

"This is also a one of a kind wire"

???? In what way?

Mark

[Barry Nave]

The glow plug wires are different than just 16Ga,14Ga and so on.
Go to search under glow plug and you will see a wright up on this wire.

[DmaxMaverick]

J54 Mark

I think he is refering to the "Type" of wire, rather than the wire itself.

The original wires appear to be thick, silicone (or similar) insulated. I'm sure GM spent a lot of bucks on deciding which type to use due to heat, elements, resistance, etc.

On my '85, I replaced all the wires with 12 ga. primary wire (green, of course) and it's been working perfectly for over 13 years with a manual controller. I can't believe even GM expected theirs to last that long. I replaced them because a couple of them got loose and rested on the exhaust manifold, burning and shorting them.

The wire you found could be from a temp sender for the glow controller, which would also effect starting. I don't think so because of the location you describe.

Did you try to follow the wire from end to end? That sure would help your situation.

[J54 Mark]

Yes, I did try to trace it. It kept breaking pieces off until it disappeared in the rear. I haven't been able to pick up where it went in the front either.

Thanks for the help. I'll get it tracked down somehow.

Mark

[tom.mcinerney]

You should have one glow plg wire to each plug[1/4" push-on]. On psgr(turbo) side the # 2 and #8 have green silicone-insulated fusible link wire. The central cylinders [#4 & #6] have teflon-insulated jumpers to run the last 7" into the tubular heat shields which surround the tip of the plugs .
On mine the cyl#8 GP wire splits from the other psgr GP wires at rear engine above/rear psgr head, just inboard of tranmission dipstick {by engine-grounding stud (securing coolant passage cap)}. The #8 GP wire drapes over rear valve cover down to #8 plug.
The other 3 GP wires route behind head in front of (rear) bracket supporting starter heat shield. Then the #2 GP wire branches off from the jumper feeds to (#4 & #6) in the vicinity of the solenoid, runs forward (in 1/4" plastic wire loom), possibly supported in plastic standoff on shock mtg bracket, plugs into GP on cyl #2.
You'll probably have to R&R the starter heat shield. The GP wiring beneath turbo a little shakey--try to tie all wires off (away from) manifold heat.
If only GP#2 is in trouble, you could save a bit of time by splicing into harness at rear block, then run jumper to front block down to #2 cyl. Should incorporate fusible section, see above suggestions....I took a look at mine today. They're labled, "0.8 SQ mm fusible" (fwiw).

[ 02-04-2004, 07:51 PM: Message edited by: tom mac 95 ]

[J54 Mark]

I think you have it. It has (had) a fusible link. Might have been helpful to mention that. Sorry.

Mark