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Discussion Starter · #1 ·
I just recently bought an 82 CJ-8. It's got a 4.2 and 178k on the odometer (has to be rebuilt, drove it 6hrs home and it ran smoother and stronger than my 7 did when it had 55k)
Here's the problem, after driving it for several days with out any kind of issues whatsoever I went to start it and it was dead. Checked the battery-ok. Thought it might be the starter but then noticed that nothing was working (lights, guages). I replaced the pos battery cable b/c it looked to be in bad shape. Now it starts perfectly, but as soon as the key goes from start position to run position the motor cuts out (lights and gauges still work).
So to sum up, motor runs perfect at start position but cuts out (literally, no spark or anything) at the run position.

Wouldn't even begin to know how to search this one.
Thanks for any input
 

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I think maybe the ignition switch needs to be replaced. It could be something else. /ubbthreads/images/graemlins/confused.gif My experience with electrical problems is first check fuses, then switches. Usually the wiring is OK, but the wiring connections, will cause problems.
dave
 

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You got big feet? Maybe you kicked the ignition switch on the colume and loosened the plug. I've done it before on a rusty switch.

Also check the tach connection. It's about 3" from the switch.
Image uploading. Refresh page to view


If thats OK then check for a voltage on the ignition coil (+) terminal when the key is in the "ON" position.

If no voltage there Then check the splice for the resistor wire here:
Image uploading. Refresh page to view


Notice the factory duct tape.
 

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MAN you have the best pics. /ubbthreads/images/graemlins/smile.gif Keep up the good work!
/ubbthreads/images/graemlins/RockOn.gif
 

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That's NOT duct tape...

THAT 200MPH SUPER DUTY CJ TAPE, AND DON'T YOU FORGET IT!
-------------------------

Check the ignition fuse first!

Turn the key to the 'Run' position, check for voltage at the Positive side of the ignition coil.

If you have juice, then you have a bad ignition module.

Leave the key in the 'Run' position, and check for voltage at the Red wire going into the module.
(thats check the harness side of the connector for the voltage)
If you have voltage there, it's the module.

If you have voltage at the module, and not at the ignition coil, it's the resistor wire.

If you DON'T have juice at either, it's probably the ignition switch.
 

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Discussion Starter · #7 ·
Well, I replaced the ignition switch and it's still doing the same thing. Runs perfect at start position but cuts out at run position. I will check the module and coil as soon as I get a working meter.
This might be a really stupid question, well actually it is a stupid question. Where is the ignition fuse?
I didn't see it labed on the fuse box, is it somewhere else???
Thanks for all of the input everyone.
 

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Discussion Starter · #9 ·
yeah, I'm pretty sure it is.
I checked the fuse-ok
I also checked for power. When the key is on "run" there is power going in to the module and there is power going out 2 of the output wires from the module. I could not find power on the coil (should be the red wire right?)

I'm confused b/c I don't understand why it RUNS in the "start" position but not in the "run" position if the module is still getting power in "run".
How would the resister wire affect this? Electrical is not my strong point (obviously)!
 

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Don't beat your self up, most people don't know that DuraSpark used two ignition circuits, just like the older breaker points ignitions.

When you are cranking, the module 'White' wire is hot, and the ignition coil is being fed from the 'I' terminal on the starter solenoid.
This circuit is retarded about 6 crankshaft degrees on the normal AMC product.
It helps the slow turning engine start easier.

When you release the key switch, it snaps back into the 'Run' position.
The coil and ignition module is now being fed through the ignition switch, instead of the starter solenoid.

When the key switch is in the 'Run' position, the coil should be 'Hot' on the positive side (red wire positive, green wire negitive to the module)
and the module 'Red' wire should be being fed from the harness.
So, turn the key switch to the 'Run' position, and test for voltage at the positive side of the ignition coil, and the harness connector that connects to the module red wire.

If you have power at both the coil and the module red wire, the module is bad.
If you have power at the module, but NOT the coil, the resistor wire is bad.
If you don't have power at either, the ignition switch is bad, or the ignition fuse is blown.

Here is a graphic to help you visulize the ignition circuit...
http://www.junkyardgenius.com/wiring/dura01.jpg
 

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Discussion Starter · #11 ·
OK, in "run" I have power at the red wire on the module but no power at the red wire on the coil. So what do I do? I was looking at the diagram from TR. I'm not quite sure, do I need to splice in a new resistor wire? If so, where to where?
 

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You would have to replace the resistive wire from the Splice with the 200 MPH SUPER DUTY CJ TAPE to the (+) on the ignition coil.

It might be easier to run a normal wire with a ballast resistor somewere in the circuit. Or a normal wire from the splice to one side of a ballast resistor. Then from the other side of the ballast resistor to the (+) o the coil. You can pick up a balast resistor from NAPA.

TR. I have a question about the red wire from (I) on the starter solenoid in your drawing. Shouldn't that wire run to the other side of the resistor wire (+) on the coil? I can't see how it would suppy full battery voltage to the coil during starting wired like that.

Something like this:


One thing I have to look into is that the Ignition switch seems to be setup to supply power to the ignition module (Red wire) during starting in a convoluted way and the Retard wire (white) has power from the "Start wire" (Blue wire) that goes to "S" on the starter solenoid. Why AMC desided to wire the ignition switch this way is, well, "Interesting" in the least. Maybe it has something to do with using a GM switch with a Ford ignition.

See this picture for switch diagram: (Warning, Not for viewing by the easily confused!!)

I3= Ignition circuit, ICM & Coil
I1= Gauges and stuff
S = Start
A = Accessories
 

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In the Run position of the switch, power is fed to the top end of the coil - through the resistor wire.
In the Start position it's still fed the same as in the Run, no change there at all, but the solenoid also bypasses that resistor wire, feeding a full 12 volts to the coil while cranking. That's the "extra" small wire on the solenoid. It simply increases the coil output momentarily while cranking. It's a holdover from the points days.

IF - it fires when only in the Crank position, but won't keep running in the Run position, look for a broken or loose wire between the Ignition Switch "R" terminal and the coil (+) side.


As I remember, the harness under the dash gets too close to the clutch/brake pedal arms. It can get caught, cut, or pulled there. Look real close there at the harness.
The other problem is the firewall feed through - the resistor wire does not like to be bent real hard, it breaks easy on a sharp bend.

The resistor wire does not "Like" to be soldered, as the nickel content is high. But you can use crimp-on splices fine.
Parts houses have that resistor wire - sometimes.
 

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Resistor wire...
Wells P/N F799
Autozone and Napa carry Wells (as well as a lot of others).
You may have to order it at the store, but it's a warehouse item, so they should have it next day.

It has 'Bullet' type connectors on both ends, so you don't have to try and cut & reconnect the resistor wire it's self.
Just by a small package of female bullet connectors, and you are off to the races! /ubbthreads/images/graemlins/laugh.gif
 

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Discussion Starter · #15 ·
Thank you guys so much. Like I said, ignition systems are not my strong point but I feel like I actually have a grasp on whats going on. Of course now I'm doing my on week at work (7on 7off) so it will be a week before I can work on the resistor wire.
Where is the splice for the resistor wire? It would be great to know where it is on the harness so I can open it up only at the connection.
This is why this board is so great. In the last couple of years this is the only problem I've had that I couldn't find by doing a search!
Thanks again.
 

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[ QUOTE ]
...
Where is the splice for the resistor wire? It would be great to know where it is on the harness so I can open it up only at the connection
....Thanks again.

[/ QUOTE ]

Look on the driver side firewall at the firewall connector were all the wires pass through the firewall.

The splice is right next to it here on the engine side of the firewall:
Image uploading. Refresh page to view
 
G

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hey since you guys are on the subject... i have pretty much rewired my whole ignition without a new harness... yes i am retarded... and for some reason i am getting power to the + side of the coil and it is running through the coil to the - side just when the key is on!??!?! also i am not getting any spark out of the top of the coil... coil is new and have tried replacing the coil a few times... been workin on this for about a month...
THANKS
NEW GUY!!
 

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I would check to be sure the (-) terminal wire on the coil (green?) goes all the way back to the module. Then check the grounds (Black) like TeamRush mentioned.
 
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the green wire does and i checked my grounds... also when i take the wires off of the - side of the coil it still shows it is hot!
 

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If the wire is off the (-) lead and it show hot, that is normal.

If you have a DuraSpark control module and the green wire is connected it should be a low voltage. I can only quess at what it should read on the (-) as I have a TFI coil on mine but it should be low.

Have you tried replaing the Ignition control module yet?
 
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