morning to ya as well, hope ya have a good and safe day.

Edit; i checked all the wires and non were burnt and still hooked up. believe the one blue wire went to some computer looking thing under the dash on the right side. the rest went into large connectors

 

On my model, a '96, the PCM provides ground for the ASD relay, fuel pump relay, crank sensor etc etc

The fact that you get some action when providing an earth suggests their is some interruption in this connection, a bad main earth somewhere, or failed PCM

think I suggested downloading the correct manual for your year, it is not possible to fault find without the electrical diagram, and associated information

 

I don't think those remote starter wires are it though? They are just possible suspects to me. Not 'likely' suspects, until I would be able to study a few wiring diagrams and saw something that really stuck out to me. They are probably still worth checking though.

Right now, if this were my Jeep with these same issues how they have evolved.. I would be highly suspicious of the oxygen sensor wires from the sensors themselves leading all the way to where they go into the main harness, and up to the PCM. I would go so far as un-doing the wrapping off the main harness, to look in there where they are located and search in there if needed. I would trace every inch of those wires. I would focus to scrutinize them very closely by checking for continuity and resistance, and voltage of these oxygen sensor wires. I would make sure to apply battery power to the grounds when checking them... I actually hope this is the reason, and it turns out to be a very vissually obvious fault staring you in the face when you get the chance to look closely at them. This makes sense for this to be one of the more likely locations for how the issue is presenting.

When checking, you may also want to think about doing as one of the ways to find an indication.. Is to keep the voltmeter connected up to the different terminal wiring of your CkPS where you can see the readings. And kind of shake and move around the oxygen sensors wiring as you go along to see what it does. The problem may change doing something to present itself on the voltmeter this way for you too.

You have a great day too! My phones kept on me. If I think of something I'll shoot you another message. I'll talk to you later.

 

A failed PCM is something to consider.. I do not think you are there to condem it yet though, but I hate to say it is a suspect in this case. If not being able to find the problem elsewhere? You may think of studying all of the PCM pins to figure out the way to correctly test them appropriately sometime.

 

I did download the manual for a 1999, didn't have a 1998. failed pcm. is that the computer?

 

Yes.. the different modules (there are a lot of them about 32 different modules) they are all called ECU's (Electronic Control Units), or computers. The PCM is the Powertrain Control Module, and it is the vehicles main primary ECU, or computer.

Outside of very limited cases. You never prematurely condemn the PCM. The PCM on these vehicles uses a communications system running throughout the entire vehicle that links everything, all of the different modules (ECU's/computers) together. In order for them to be able to communucate with one another how they need to, and with the main ECU-PCM. It literally does this by way of a single wire running throughout your Jeep with micro pulsed electronic signals. This is known as the PCI Bus on your model year of Jeep (it is a Chrysler specific Bus.. But, it is universalized and coordinated with all other vehicle makes - with other manufacturers having their own specific types of communications Bus systems too.. This happened when the OBDII system was first being implemented as a way of better being able to find and diagnose electrical faults by way of the OBDII vehicle codes).

The Chryslers Bus system is designed in a certain way where a fault occuring in one of the systems causes effects on other parts of the whole 'organism', in the different systems. Some of this was designed by the Chrysler engineers to happen on purpose, in order to be able to point out faults that are occuring with a neighboring module that is no longer able to 'speak' for itself. It is complicated.. Sometimes, more often than not, it seems a fault in a non-critical component can inadvertently mess up, or even shut down the main primary system(s), and/or multiple other vital components as well.. If a mechanic or auto technician does not understand the system? Then, they may very well condemn what they see as showing wrong on their scanners when there is nothing specifically wrong on that component, or there in that system which is showing as faulty. For example; a short in the non-essential door jamb wiring boot may cause your Jeeps secondary main computer, the BCM, to behave erratically causing the Jeep to do all sorts of wierd things, and to not operate correctly. It may do this throwing a main computer (PCM) fault code too, and then you might got a mechanic or auto technician telling you that you need to replace your Jeeps PCM.. because of a simple short happening in the door jamb wires.. when just correcting the door jamb wiring (a $0.50 fix) would have completely solved the whole problem...

Make sense?

 

ok makes sense. still freezing rain/ice...so can't do much. I found a few youtube video's on checking the pcm, so I'm gonna check that when I can safely walk to the jeep with out falling on my .... lol

 

because you have some action, and some additional action upon providing a ground path, I would suspect first the PCM has somehow lost its main earth

I would clean the main terminal on the block for sure, and test the wire for continuity

In addition, I would completely remove any additional wiring you installed. Unfortunately a needed step when such a situation arises..rectify any work that took place just before

 

as soon as the jeep wouldn't start I took all my wiring and the remote starter out. Since it was freezing rain all day, I spent the day studding the wiring diagrams and have at least narrowed my search area...the blk orange wire was for taillights and such, they all still work so I eliminated them for now, but the blue wire I hooked to went to the pcm, asd relay, back up lights. so I'm gonna check the back up lights to see if they work. I will also be taking the advice above and checking the main ground and the ground on the engine, as well as testing the pcm Thanks again for the help. dt

 

Man, that CJ5 you showed is awesome!

I have a real good buddy his name is Dave. He taught me soo much about vehicles. I am sure he is probably the best mechanic I'll ever know. I've known him for a long time. For fun, I used to go over to his garage and help work on vehicles with him on my days off. He is an independent mechanic who got a start with a background in diesel mechanics.. and made it in the business on his own with some tools, word of mouth, and a phone number. Used to travel to peoples homes since at one point he did not have a shop or garage. He has had his own successful shop for years now. He now mainly specializes in building high horsepower engines. I swear the guy could find and fix anything. A lot of people place high value on their vehicles, and are attached to them.. The reactions I've seen from the different people when getting their cars back again, and in working condition after maybe having tried taking their cars to be fixed by others who could not fix them.. and getting them back was worth being able to see!

Him and I did quite a few ground-up vehicle restorations back in the day. A lot of Camaros (my favorite vehicles), and a couple of older Jeeps... A CJ5, or two.. and CJ7's. It was some fun times! Whenever I am back in town at the beach, I ussually always try to make it a point to stop by and visit him at his shop. If I am driving one of my Jeeps we ussually always hang out, and then do some work on them.. They are always needing something you know! Brake fluid, or whatever...

Good luck!

 

found another issue, the down stream 02 sensors wires were zip tied up, but hung down just far enough that the drive shaft rubbed the one wire bare and was grounding on the drive shaft....I unhooked it. wire was rubbed threw after the connector. still not starting. took off the ground wires on the block, cleaned them up and hooked them back up. so far the jeep has been kicking my tools but. 2 test lights and 1 multi meter...lol leads got cold on the the multi meter and broke with a little pressure...mix of snow and ice today....

 

What's next on the list of things to check? I know you said your voltmeter leads broke in the cold, but were you able to re-check the values you were getting at the CkPS again, since after getting done with cleaning the engine grounds, and disconnected the faulty oxygen sensor wire that was shorting out? Maybe the readings at the CkPS have improved?

Maybe double checking all of the fuses if you haven't checked them?

The short being found in that oxygen sensor wire makes me become suspicious about it with where it leads, and the rest of them. What kind of shape is the rest of those wires going to be in? Even the condition internally underneath of these wires insulation, if it was shorting out possibly getting heat built up inside of there?

 

I tested the pcm, and power is good to it, I have to restest the ground for it as I didn't realize it till about midnight that I had the meter on a bolt and not the battery, so i don't believe the test will be accurate.. i'm testing the wires leading into the pcm at the connector pins.

I have miss spoken about the wire on the o2 sensor, i didn't really check the wire color and see what it matches in my diagrams from cruiser54's sight. so I'm not sure it's a power, signal or the ground wire that was bad. the front o2 sensors wires, while a bit greasy, appeared ok, but as you mentioned who knows what lies underneath the insulation. I have another meter and will be testing the crank sensor values again today. Havent had as much time to work on the jeep since saturday, I take seniors and disabled hunters out in the woods and allow them to hunt out of my vehicle (providing they have a permit to do so) I'm supposed to take a person out this morning, but that'll give the temps a chance to warm up....cold, windy, heavy wet snow yesterday on top of the ice storm ugh

 

one of my next test might be to test the wife's patience and see if we have the funding to just get another jeep....lol most of the grounds I have tested have read 0.01 on the meter and had a steady beep. I still have to test the grounds at the pcm and check the fuses again.

Edit: If I would run a ground wire from the battery to the ground on the asd and I would get spark, would that tell me I lost the ground on that circuit..or is that a bad idea?

Edit: I have 3 at terminal 32 and 2 at terminal 31, but cannot get a reading for ground at the crank sensor. if I turn the meter to test for volts I'm getting 5.13 at all 3 plug for the ckps. does this point to a failed pcm, since I have ground coming in, but no ground coming out of the pcm. thanks again for all the help, dt

 

You should be able to add in extra grounds to see what it does, and it should not be a problem (as long as you stay on the ground circuit).

Since you have been looking at and testing the PCM.. With the PCM disconnected, you could try to Ohm out all connections to check for faulty wire or the connector itself.

How is the condition at the base of your Jeeps PDC, or relay boxes under the hood and inside of the Jeep? You could check beneath the relay bank and fuse boxes for any corrosion. Clean up the backsides of these, and check the connections here in these places may help...