Electric problems

Walter · Post by **Walter** » Sat Mar 17, 2012 10:18 am

Hey guys,
I am not a mechanic so bear with me. I have a question about starting problems. This is what I have, just bought a 1984 GW for parts on a 1983 Cherokee we have. PO says that the inline six in the GW ran fine until it wouldn't crank one day. He assumes it is an electrical issue. I would not be surprised judging by the current awful condition of all the wires on the vehicle ( excellent body however). My question is, how much can I disconnect from the old wiring and still get the vehicle to run? Does the ECU control Anything that would prohibit it from running? I am sure it is bad, the gel coating on the back has melted out. Is that an indicator of another problem as well? I have hooked a good battery to it and jumped the solenoid. I can get the engine to turn but not fire, even with a little fuel in the top of the carb. Any suggestions would be great. I am considering redoing this vehicle as well since it is so solid and the engine compartment is so clean. PO added a lift and new tires and does not appear to have been offroaded. Interior is trashed though.
Thanks

Post by **Stuka** » Sat Mar 17, 2012 10:45 am

So it will turn over when jumping the solinoid but not when using the key?

The solinoid will get the engine to turn over, but it wont send power to the dizzy. You need the key to be in the run position for that. Assuming those wires are still connected.

As for the ECU, you will actually have two of them. One to operate the carburetor, and the other to operate the ignition. You don't need the one that controls the carb just to get it to run. The ignition module however has to be working. Its pretty easy to tell them apart. The carb ECU has a huge plug in the top of it. The ignition module has wires that go out the side of it only. If the ignition module is the one that has had the gel leak out, then you would need to replace this. They do not cost much thankfully as its a standard ford ignition module. Once you get that replaced, that will fix the no running issue, although I do not think it has any control over the engine turning over. But I could be wrong there.

Walter · Post by **Walter** » Sat Mar 17, 2012 12:44 pm

Thanks,
When I go to the parts store what do I ask for? The module that is leaking gel is on the top of the drivers side fender inside the hood. It has two sets of wires coming out of the back side and plugging into a harness.

Post by **Stuka** » Sat Mar 17, 2012 1:18 pm

That sounds like the ignition module, which is what you want to ask for.

Walter · Post by **Walter** » Sun Mar 18, 2012 5:05 pm

So, I replaced the ignition control module from my 1983 Cherokee and still nothing. However, I did notice that I was getting a clicking sound coming from a small (1.25-1.5 inch) blue box plugged into some wires behind the carb. I could not swap one since the older Cherokee does not have one. Anyone know what this part may be? Could it be my problem? I still am having trouble posting pictures, but I do have a photo of it I can send someone if they think they can help identify. Any ideas?

Post by **Stuka** » Sun Mar 18, 2012 5:43 pm

Here is the photo he took. I have no clue what that box is.

Tad · Post by **Tad** » Mon Mar 19, 2012 4:24 am

Any numbers on it?
Looks a lot like some of the relays I have installed.

Walter · Post by **Walter** » Mon Mar 19, 2012 6:48 am

Yeah, it is a relay. Just got one from the parts store and going to plug it in and see what happens. I will keep you all posted.

Walter · Post by **Walter** » Mon Mar 19, 2012 11:21 am

I plugged the new relay in and still nothing. It is still clicking which leads me to believe that it is getting power to that point. Again, I can jump the solenoid and get it to turn but no fire?

Post by **Stuka** » Mon Mar 19, 2012 1:19 pm

When jumping the solenoid, is the key in the run position?

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Walter · Post by **Walter** » Mon Mar 19, 2012 5:27 pm

Yeah, my wife was inside and I was under the hood. There are so many wires under the hood of the GW that are not in the Cherokee. And... There are tons of them unplugged and others burnt off. Hence my original question, how much can be unhooked and still crank? I am probably just going to part if out but I would like to know if it runs so that I know whether or not to junk the motor or find someone who can use it.

Walter · Post by **Walter** » Mon Mar 19, 2012 5:30 pm

I also have a 1977 CJ5, and I can jump the solenoid and crank it without a key or anything. I discovered this when my solenoid went bad and I was trouble shooting to locate the problem.

Post by **Stuka** » Mon Mar 19, 2012 6:36 pm

Oh you can crank it fine without a key. But the distributer doesn't get power when doing that. Thats why I asked if the key was in run, that way the distributer gets power.

If you have a multi meter, it sounds like its time to start checking voltages.

But before that, pull a spark plug (or use a spare) and connect it to a plug wire, ground the threads to the intake, and turn the engine over. If you don't get any spark, the engine is never going to start. If you do get spark, then there is a different set of problems at hand.

Walter · Post by **Walter** » Tue Mar 20, 2012 3:50 am

I figured pulling plugs was the next test. Do I need to check each plug or is one an indicator of the rest?

Post by **Stuka** » Tue Mar 20, 2012 6:13 am

You can check them all if you like, but if one doesn't work, chance are the rest wont.

Walter · Post by **Walter** » Tue Mar 20, 2012 5:14 pm

No spark. Start checking the ignition coil next?

Post by **Stuka** » Tue Mar 20, 2012 7:24 pm

Well, it can mean quite a few things unfortunately. It could be the ignition module isnt getting voltage telling it to send a signal to spark, it could be the coil, it could be the wireing going to the distributer, it could be the distributer itself, etc.

You are just going to need to grab a multimeter and start checking voltages down the line.

Walter · Post by **Walter** » Thu Mar 29, 2012 4:02 am

Just an update:
I have not tried tracking the problem down yet. I have devoted my focus on completing the body work and paint on the 1983 Cherokee. I am getting close now! When I get that complete I will post some pictures and start working with the starting problems on the '84 GW.
Thanks for the help so far.

Post by **Stuka** » Thu Mar 29, 2012 6:11 am

Cool, can't wait to see how it is turning out.

talntar · Post by **talntar** » Sat Mar 31, 2012 10:36 pm

run ajumper fromthe batt to the pos side of the coil and see what happens.

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