Not good with Electric...

[steveno]

Hi, wanted to throw this out there to see if any possible diagnosis....
I have an 84 CJ7 , 6 cycl., TBI from chevy 4.3l, Spark control, HEI coil.

Ok, everything was running fine, went to start one morining after a rain. And just got a click, so I took the cherokee to work.

Got back to the CJ and tried to start it, same thing. Sometimes the aftermarket alarm wich has a kill feature acts up. (which I will be removing) So I checked wires and fuses on that and noticed a horn wire was broken from one of the connectors to a horn.( I have four horns aligned in a row) Anyway connected that and messed with the alarm some more got the jeep to crank but didn't turn over. I also noticed I didn't hear the fuel pump prime as key passed acc to ignition to start. After trying a few time with a friend listening for fuel pump we noticed some smoke in engine compartment. The isulation burned off a wire, it goes from a ground block on the firewall the firewall at the blower. Two wires going to blower a brown one that clips in and this one right next to it that appears to go to the blower. the wire appeared to be intact so I taped it. I also noticed a ground wire from the battery, the side post not top post of battery. The wire went to a ground block with a few other wires. now the ground that burned went to another block. Anyway the battery ground was touching the mounting bolt of the block a friend said that could be the problem. So I remounted so it wouldn't touch. During this the starting selonoid starting making noise, loud clicking. and engine wouldn't crank. I replaced that and it cranked again. I noticed no fuel in the TBI and check for spark, nothing. Thinking maybe fried ECM and or control Spark Module. Getting ready to mess with this one more time before I take to mechanic or make worse. Oh I replaced fuel pump, still no prime from that. thinking the ecm isn't sending signals to anything. Any ideas?
Thanks.

 

[BusaDave9]

Okay so you turn the key and the starter won't turn the engine. It's not a problem with the fuel injection or ignition. It's a problem with the starting system. There may be more than one problem but first things first.

Have someone in the driver seat turn the key to run. Use a jumper cable to jump from the positive end of the battery to the large cable on the stater solenoid. (the big black cable on the left in the above pic)
This will test the battery and starter (your battery will need a good ground)
With the short you described your battery could be low.

 

[Sam5038]

Check the fuel pump relay. Should prime for 3 seconds when the key is turned on.

I have a 4.3ltr V-6 in my Jeep.

 

[BusaDave9]

And maybe your lug nuts are loose. But if they are that's a separate issue. Please don't' be offended but lets stay focused. If you turn the key and the starter won't turn the engine then we have a problem with the starting system. Once we get the engine to crank over and IF it doesn't start THEN we can go on to the next step.
The starting system is very simple. Don't take your jeep to a mechanic for a starting problem.

 

[steveno]

Ok, I hear you. I will try the the jump tomorrow and check the starter also. I just feel like there is something more going on with the ground and the ground wire for the blower getting hot. And now the fuel pump not priming and the starter selonoid going bad when cranking too much. Seems like a short somewhere, checked fuses and relays I will start checking fusible links more and figure out the volt meter to at least check for breaks. I think it's something simple but causing alot of pain....... The reason I was inquiring on getting a mechanic is I have no clue on checking the ecm and spark module. They are cheap enough to replace used but that isn't fiixing the problem and don;t want to blow another if that already happended. Think I will rip the alarm out and go from there. I will recheck all fuses and relays and wires and grounds. Then links.

 

[BusaDave9]

Yes I really think there could be more than one problem. But we must take it one step at a time. If you turn the key and the starter isn't working you have a problem with the starting system.

If the engine won't crank over then the best fuel injection in the world wont get the engine running.

Lets stick with the starting system for now.
Is your battery good? If that's the problem then jumping if with another car will get it running and you would know you need a battery.

 

[Sam5038]

I agree with checking the starting system first.

That's the bad part about it. When I did my conversion. I used everything from a 1995 S-10 truck. I even have the Factory Service Manual for it. It shows the complete wiring harness and color codes. That way I can diagnose what it wrong. If you don't know what was installed when the conversion was done. It will be hard to find the problem

 

[dunebuggy18]

Busa is right... Electrical issues can drive you crazy, but the trick is to chase one issue at a time in logical order. Many wierd symptoms can come from one or two seeming unrelated sources. Stick to the basics, and fix your starting circuit first. THEN if it won't start when cranking, we can help deal with that.

Good luck!

 

[steveno]

Thanks,
I really apprieciate the help, I have access to the PO of the Jeep. He is letting me know what wire is which if I'm not sure. He built it from the ground up. I have the kids this weekend so not really getting time to get to it, but later this week after work will be better. This is the same Jeep that was on the TBI write-up that was sought after on Bxsted Jeep if anyone is familiar with that it was a while back. Anway I agree I'm going to start with begining of the the process, starting, spark, fuel etc.... First going to check again for fusible links and bad wires and conections... I have some pics of the wires I will post and take some new ones that might help with diagnosis or at least give you guys a better idea... thanks

 

[BusaDave9]

Keep us posted.

No need to contact the PO yet. We have a problem with the starting system. Yes, I know you are convinced you will have a problem with the fuel injection after we get the starting system working but don't waste 2 minutes on the fuel pump or ignition until we know the starter can turn the engine.

I am not convinced (yet) there is anything wrong with the fuel system. It sounds like a short may have drained the battery.

Jumper the battery to the starter as described. Or have you tried having someone jump you? I think your battery is dead.

 

[cerrajero]

4.3 as in the chevy?

my questions are these ( with explanations )
manual tranny or auto? ........(looking for nuetral safety switch )

solenoid on fender or on starter ( also has connection for nuetral safety )....some chevys do on starter

aftermarket kill?.....where is it wired up at (interrupting the fuel pump or the starter?)

steering column OEM or ?

 

[steveno]

Yes aftermarket alarm, which will be the first thing removed. It has a kill on it. Has been a pain since installed. manual T-5 . 4.3L TBI from chevy 1500. Starter selonoid on fender. Going to do some checking tonight on the fusible linds especially the wire that burned the isulation. Def. something with a ground i believe.

 

[steveno]

Don't even know why I wrote "aftermarket" alarm.... but it.s got to go. When did Jeep start installing alarms on wranglers??? 2000's?

 

[cerrajero]

yep agree with Busa on this one as well
i am picturing a mess of different colored wires with about 100 butt connectors
i would turn the key to "run" and start metering the connections from the ignition on the column (the fuel pump primes on the run position not the start)
and start replacing butt connectors one at a time and testing after each
i would definitely remove this "kill switch"

just my 1 cent

 

[steveno]

I the above pic you can see where the burned wire goes to what I believe is the blower motor. Of you look close to the left of that wire at the firewall there is a spade where I unhooked the other wire for the pic.The other wire is a tan wire for the blower. The wire are right next to each other so I assume the black wire is the ground for the blower which is from a blazer. That's info from PO. In the bottom pick you can see where that wire grounds to the cluster of grounds to the left. The other block of wires in the bottome pic attached to the firewall, I thought were grounds but the black wire with the red zip ties is from the positive front post of the battery so I guess that would not be a grounding block. Also that same wire from the battery was touching that mounting bolt in the block, maybe that had something to do with a short?

 

[BusaDave9]

Where do the 2 big cables go? To the battery itself? If this is power to things like the blower they should be switched but I don't see why they would use big battery cables for switched circuitry.

 

[BusaDave9]

So the terminal block on the right is battery 12 volts and the one on the left is ground. Both of these go back to the battery?
The PO should have used fuses. It looks like a short on the blower drained your battery.
I'd like to know more specifically how these terminal blocks are wired and what, besides the blower is connected up to them.
But the bottom line is we will want to disconnect the blower and other accessories connected here. Then you should charge the battery and try starting the engine. When you connect the blower and other accessories back up you need to fuse them.

 

[BusaDave9]

So this cable is connected to the battery positive post. It was also shorting on that bolt. That's the real problem that drained your battery and prevented the engine from starting.
Then there's the shorted blower wire. When the firewall was shorted to 12 volts, power went through the burnt wire back to ground.

 

[cerrajero]

correct me if i am way off but this ground block is supposed to be a junction for the wires and NOT the actual ground......meaning that there should be another battery cable coming from there going down and attaching to the frame or the engine block?

 

[steveno]

I will answer those questions when I get home(where the wires go), at work right now. But yes they are the the cables from the front posts of the battery. Any I did remeber when trying to start the Jeep when it did crank during a few tries the main negative post on the battery did have a puff of smoke. I will pull the blower fuse and accessories fuse after I remove the alarm and charge the battery and give her a whirl. Will try to get more pics up also.