Dead yet again

Okay, after a second read I'm confused at what a blinking light means. You say that one "should blink" but then you say, "if it blinks you have a bad coil."
In any case, I took my test light to it while my wife turned the key. Both had a weak light when she turned the key on, and one of them made it get brighter when she turned the key to crank it; the other one did nothing but give off a weak light during the cranking. One thing I'm sure of, there was no blinking out of either one.

So what does this mean? It's good or it's bad?
 
I just read online another way to test the coil with a multimeter. From post to post should read between .75-.81 of resistance and from one post to the main plug should be between 10k-11k of resistance. For the former I got .6, and for the latter I got 8.8k.
 

Okay, is this the wire you're talking about?
Aaron, I am having a similar problem and have been looking for a wiring schematic. Do you know if the thumbnail you posted is the same for a 1990 YJ 2.5L 4 cyl manual?

My jeep has no power to the top of the coil nor does the heater fan have power. I have traced a green wire with a white tracer from the starter through the starter module back to a microprocessor. I am trying to figure out if the ignition module or microprocessor is bad. My dad's co-worker said I should get a diagnostic sheet that shows the draw for each module and wire. That would help run down a power issue with a fuse wire or resistor.
 
Here, this one is for the engine controls of a '90 2.5L. I made the picture huge, so after you click on the thumbnail, click it again when it opens in a new window. Let me know if you need the schematic for the body and fuse box too.
 

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If the light is blinking that means the coil is getting a signal from the module and you have a bad coil. From your resistance check and the no blink condition,,,sounds like the coil is fine. You have a "spark box"? Is the rubber insulation underneath show signs of burning/melted? The module in the dist. original?
 

AAAHHHH!!!!! This is killing me. I thought I'd found the problem with the coil, but it looks like that's not the case now, with what you're saying Ken. Right now, I'm out of town, but I'll be back to Ft. Polk tomorrow. To answer your questions though. . .

1. I'm not sure what a spark box is, or for that matter if I have one. If you tell me what, or where, it is, I can check it and let you know.

2. Which rubber insulation are you talking about? Underneith the spark box?

3. As far as I know, yes, the module in the distro is the original. I've had the Jeep for 5 years and I've never changed it, and I can only assume it is.

From what you're telling me, it sounds like I have a problem somewhere in the distro, and that it's not doing its job in getting the signal to the coil to fire...correct?

If that's the problem, should I just replace the whole damn distro, and save myself the pain of trying to figure out 'where in the disrto' the problem lays? It's only $45 at Advance Auto.
 
AAAHHHH!!!!! This is killing me. I thought I'd found the problem with the coil, but it looks like that's not the case now, with what you're saying Ken. Right now, I'm out of town, but I'll be back to Ft. Polk tomorrow. To answer your questions though. . .

1. I'm not sure what a spark box is, or for that matter if I have one. If you tell me what, or where, it is, I can check it and let you know.

2. Which rubber insulation are you talking about? Underneith the spark box?

3. As far as I know, yes, the module in the distro is the original. I've had the Jeep for 5 years and I've never changed it, and I can only assume it is.

From what you're telling me, it sounds like I have a problem somewhere in the distro, and that it's not doing its job in getting the signal to the coil to fire...correct?

If that's the problem, should I just replace the whole damn distro, and save myself the pain of trying to figure out 'where in the disrto' the problem lays? It's only $45 at Advance Auto.
I think Ken is reffering to the ignition module under the windshield washer tank mounted on the driver side fender well. The Rubber insulation he's reffering to is the silicone filler used to seal the electronic circuit board under the aluminum housing.
 
Bittersweet Success!!! I just got back from AutoZone where I had the Ignition Module tested and it failed. I ordered a new one and it should here tomorrow afternoon.

I'll post tomorrow if it works.

Thanks everybody!!
 
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Alright gents, I'm back in business. It was the Ignition Module, and it fired right up after I put the now one in.

Thanks for your help!
 
Check for condition of your ground wires!!(previous experience!) And to check the resistor on that wire, you can have continuity and the resistor be bad. You have to read ohms on a resistor. Sorry i popped in late!!
 
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Ken, it's the one under the coolant overflow and windshield washer bottles, on the driver's side wheel well.
 
I think Ken is reffering to the ignition module under the windshield washer tank mounted on the driver side fender well. The Rubber insulation he's reffering to is the silicone filler used to seal the electronic circuit board under the aluminum housing.


Mike I am having a similar problem on my 1990 2.5L 4 cyl manual. I looked under the windshield washer tank but failed to find it. I looked up the part on the internet and it looks like a somewhat flat metal square with two sets of wires and connections correct? Aarron gave me a wiring diagram to help trouble shoot the issue. I have been waiting on my buddy to come by to help with the trouble shooting. If I could find the ignition module and get it tested I would be that much ahead. Thanks for any help.
 
Dylan, here's a picture of a ignition module for a '87-'90 2.5L. As far as testing it goes, I don't know. All I did was make a phone call to AutoZone and they said they hadn't done it in awhile, but they still could. Sure enough they figured it out and it came up bad on their tester. It's just a phone call once you get the part off. Let us know how it comes out.
 

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Aaron great picture. Found it on left side of engine mounted on fire wall. Though it tested okay. Still hunting. Maybe if I give more information someone can help. When the ignition switch is turned the gauges come up, radio comes on and you can hear the fuel pump come on. Further turning of the switch gets absolutely nothing. We changed some parts chasing the intermitant problem and now we have a new starter, new alternator, and a new starter module (that part really was bad) We tried to hot wire the engine from the battery to the starter and could get the engine to turn over but not to fire. We found that there is no power to the top of the coil. Finding the ignition module (ECU) works has me with still no Jeep. There is more. The heater fan has no power as well. I am sure this is a related issue. I have traced a wire from the starter to the starter module through the fire wall and back to a microprocessor. I might be in over my head now. If it is a simple as a fuse wire where do I start? Or should I take it to someone with a computer diagnostic machine? Thanks for the help so far.
 
Aaron and Mike, thanks for the help I found a bad fuse link wire. As soon as I get it changed I should be back on the road. Thanks for all the help.
 
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