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Chris
Chris, Shop Foreman
Category: Jeep
Satisfied Customers: 3172
Experience:  Jeep Certified Master Tech
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1999 grand cherokee limited, no crank issue, I can use a

Customer Question

1999 grand cherokee limited, no crank issue, I can use a jumper wire in the starter relay pin 30 to 87 and the jeep starts and runs. I have a new battery, starter, pcm, tcm, solenoid pack inside trans(45rfe, mopar updated), battery cables, ignition switch. I checked wiring to and from modules, grounds good. My gensis scanner shows trans in park and neutral are good. I do not have the pin code for the rebuilt pcm and I do not have codes or theft lights on. I have a factory service manual and it is not making sense, all checks ok? Was working when purchased 6 months ago now has been sitting fur 6 weeks trying to figure this out, I am a ase master heavy mechanic not a small car one and it is pissing me off so I figured to give you guys a try, I live way out in the boonies and no way of getting to a dealer if needed. What do you think?
Submitted: 1 month ago.
Category: Jeep
Expert:  EricFromCT replied 1 month ago.

Hi. Is this a v8 or a v6?

Expert:  EricFromCT replied 1 month ago.

Nevermind. I see it is a 4.7

Expert:  EricFromCT replied 1 month ago.

Do you have a test light? WIth the starter relay removed and the key ON, do you have power on pins 85 and 30 of the relay?

Customer: replied 1 month ago.
it does have power at that pun with key on
Customer: replied 1 month ago.
need help, and $38 bucks for this answer is not worth it, need better help for this price!
Expert:  david craig replied 1 month ago.

Hi Im David, if you have power at the appropriate places at the relay base, and it starts and runs with 30 and 87 jumpered. then the relay should be the culprit wouldnt you think? have you tried another one?

Customer: replied 1 month ago.
the relay tests fine, and i tried others, not it thx
Expert:  david craig replied 1 month ago.

have you checked the wiring from the relay to each place it goes for high resistance shorts to ground? or the condition of the wiring i.e. corrosion producing high resistance? have you done a pull test on any wiring to make sure the pins are locked into their connectors? and not pushed back a little?

Customer: replied 1 month ago.
I checked the wires, ohm'd and voltage drop and all were in specs.
Expert:  david craig replied 1 month ago.

heres a print if it helps at all.

Customer: replied 1 month ago.
Thanks, ***** ***** a factory service manual with all the diagrams
Expert:  david craig replied 1 month ago.

this doesnt make sense. I have to believe its the pcm. I know you replaced it. but thats the only possible thing it can be. it either needs reprogrammed, reflashed, or replaced again. did you check the grounds at the pcm area?

Customer: replied 1 month ago.
That's were I am at and why I needed some fresh eyes, I came to the same conclusion and did replace the pcm and tcm , I may see about a different pcm, I emailed the company and am waiting to hear back, I checked all grounds and ran test grounds and power to eliminate all possibilities
Expert:  david craig replied 1 month ago.

well you are as thorough as they come my friend. I wish there was something else I could suggest. Have checked all the voltages/grounds for the DLC?

Customer: replied 1 month ago.
Yeah, this has got me, I have never ever had a issue I could no fix in my 30 years of doing this, so I am pissed off, I am sure it is something stupid but I feel I have covered all avenues
Expert:  david craig replied 1 month ago.

sorry man. ive been a mechanic for 32 and I am out of thoughts. I think its going to come down to a loose ground somewhere or as mentioned the computer. i can opt out and see if another tech might have a different thought.

Customer: replied 1 month ago.
Well I hope someone has come across this before
Expert:  david craig replied 1 month ago.

good luck

Expert:  Amedee replied 1 month ago.

Hello!

Different expert here.

I would like to help.

Customer: replied 1 month ago.
Any help is good at this point
Expert:  Amedee replied 1 month ago.

I am just reading the post to get cought up

Expert:  Amedee replied 1 month ago.

Does the engine crank over if you supply power to the female pin 87 of the starter relay with it removed?

Customer: replied 1 month ago.
supply battery voltage to pin and jeep starts fine, relay is good, circuit is good
Expert:  Amedee replied 1 month ago.

Ok, excellent! They is has to be a bad connection where you plug in the relay.

Expert:  Amedee replied 1 month ago.

Unless your missing a ground going into the relay on pin 86? Is that the case?

Expert:  Amedee replied 1 month ago.

Looking through this thread I could not see if you said that there is a ground going to this relay or not..

Customer: replied 1 month ago.
The ground is through the solenoid pack in trans
Expert:  Amedee replied 1 month ago.

Right. So are you getting a ground from the solenoid pack in the transmission to the starter relay?

Customer: replied 1 month ago.
Testing shows yes, and my genus is shows good
Expert:  Amedee replied 1 month ago.

So all three inputs to the relay check out good correct?

Customer: replied 1 month ago.
ohm'd out good and voltage drop is ok, that's were I am at and had to suck up my pride and ask other techs if they have come across this issue
Expert:  Amedee replied 1 month ago.

NO problem. We have all been there before.

How are you checking for a ground to the relay? Can you upload some pics, video or maybe we can talk on the phone?

Customer: replied 1 month ago.
Power probe , test light and dvm
Expert:  Amedee replied 1 month ago.

Ok, send some pics..

Expert:  Amedee replied 1 month ago.

Is the relay clicking when you turn the key to the CRANK position?

Customer: replied 1 month ago.
No which leads me to believe it's that circuit but it tests good ?
Expert:  Amedee replied 1 month ago.

Chances are you have not tested the circuit under a load. Thats when you get the most accurate test results

Customer: replied 1 month ago.
Used a test relay with test with test pins
Expert:  Amedee replied 1 month ago.

Let me see

Expert:  Amedee replied 1 month ago.

I think something simple is being overlooked. I dont think your testing it correctly and therefore not getting the desired results. That's why I would like to see what your doing and how your testing it. Remember, you asked for a fresh set of eyes.

Customer: replied 1 month ago.
No problem and no offense here , getting ready to eat with friends and will get to it next weekend
Expert:  Amedee replied 1 month ago.

Sounds good no problem.

I will be looking forward to hearing from you.

Customer/p>

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