Paging Wiring Experts!

I got my /5 built enough to light the candle this afternoon. Freshly rebuilt 360 came to life just fine. When the oil pressure plastic line melted against the exhaust manifold and started to leak, I took out the ignition key. Funny thing is the engine kept running.

Since I don't want to be pulling the coil wire all the time, does anyone have an idea on where to look? I rewired the whole thing with a painless harness. Everything else seems to be wired correctly.

Any help would be appreciated.

 

Switch may be bad.
Has happened to me 2 times. Pull the key and it kept running, even the off post.
Check the wires on the switch one more time to make sure its all hooked up right.

 

Hey There,

Something to check is to see if the coil wire is on the IGN side of the switch, and the alternator exciter wire is on the ACC side. I've heard the alternator can bleed back through and keep the ignition hot.

Otherwise, try tracing back the coil wire to the switch and see what else connects to it. Any wires that connect with the coil wire at the switch could be the culprit.

 

Like said above, check to see if the coil wire goes to the IGN side of the switch instead of the BAT side.

 

old bill pretty much has it right with the alt. feeding back and keeping it runing. mine did that for years, had to stall it in gear to shut it off. i got so sick of it that i did something about it. i had swaped my jeep to a chevy alt. ( after wheeling was killing them, i found the chevy ones were cheaper ) and after doing this is when it started doing it. what ended up fixing it was a diode in one of the wires from the alt. it hasent done it since.

 

The 4.0 engine conversion in my wife's 83 -7, with GM 10si alternator did this. Cured it with a diode in the alternator wiring. I believe it is the number one wire. I can find out for sure and get specs for the diode I used if you want (radio shack). Been working for 7 years now.

 

Thanks for all the positive input....

I just checked the coil and there is no voltage there with the engine off. I checked a couple of diagrams and I'm 99% sure I have the alternator connected properly -- field terminal (#1) and the #2 terminal jumpered over to the battery terminal. I've got nothing hooked up to the I terminal on the starter relay -- just on the Start side. I'll peek under the dash and see if I have the switch bunged up.

I'm using the painless harness, and I've rechecked the wire numbers a dozen times. What I haven't done yet is put the ballast resistor in place. I've got +12 going to the coil all the time. But I didn't think that would be an issue.

Thoughts?

 

Jeep had a factory bulletin at one time that dealt with this issue
as mentioned earlier, alternator feedback with Delco units the culprit
they had a diode pack that plugged in at the alternator, in between alternator and factory wiring plug
I still have some or Radio Shack as mentioned
funny, after I rewired with Painless 2 1/2 years ago, on start-up, my V6 did the same thing; had to go dig up one of these diode packs to cure the problem
I can't seem to locate the bulletin at the moment, was going to give the diode specs
someone else here should be able to help

EDIT: the ballast resistor should be hooked up only if still running points type distributor; reduces voltage tp the points; won't help with the after run condition FYI

 

Where does the diode mount? Too the field terminal or the other one?

 

lemme go look at mine........

 

it goes directly onto the #1 post of the alternator, inline, between your other harness connector and the alternator

 

here is a pic of mine
it's the red wire (like in the movies!)
you would remove #1 wire from alt plug; install the already prepped end of the diode pack into the plug; reinstall on alternator; then reconnect the removed wire into the connector furnished on the other end of the diode pack (obviously I'm not using the factory plug on the alt)
easy!
but....not all Jeeps with Delco alternators needed this..as to why ??..go figure

 

Jim's nailed this one Bob.
I used a 1kV, 2.5 Amp silicon diode. Put it in the number 1 wire with the arrow or stripe facing towards the alt, allowing current in but none out. I soldered mine in, heat shrinked the connections, and covered the whole thing with about 6" of fuel line heat insulation sleeve(woven fiberglass?). I think the diode gets hot like a resistor, didn't want anything touching it.

I got 3 at radio shack for $1.49.

Jim, how about a pic of the factory fix?

 

Oops, you beat me to it.

 

Thanks a bunch, fellas. I wrenched my back crawling between the seats to get under the dash last night and my back is killing me. I verified every stinkin wire, and then metered the switch and it "seems" fine.

Radio Shack or Napa for the diode?

 

BTW,

my #1 wire goes back to the bat post on the alt.

bob

 

This has been discussed before, but the number one wire should go to the "charge" or "amp" light, or to a standard dash light bulb, then to keyed hot power.

Number 2 can jumper to the Bat post on the alternator. Better yet run it to a junction point somewhere away from the alternator so it can "remote sense" current flow somewhere downline from the alternator.

I run my alt charge wire to the starter solenoid where the positive battery cable attaches. Factory setup is like this and is preferred over running it directly to the pos bat terminal.

 

my Painless instruction booklet advises #2 wire to go straight to the alt post
can't see that it would do any harm the way both of you are wired though