Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here! ZJ (93-98), WJ (99-04), WK (05+)
All ZJ/WJ/WK specific tech questions asked here!

Jump mistake now crank no start

Old 10-19-2016, 08:19 AM
  #1  
Newbie
Thread Starter
 
Join Date: Oct 2016
Posts: 1
Model: Cherokee
Default Jump mistake now crank no start

It was very dark out this morning and I made the mistake of crossing jumper cable wires on my 99 Grand Cherokee. (The Cherokee has the bad battery.)
I was able to jump it yesterday afternoon. When I try to start it after the mishap I get a crank, no start situation. All lights work fine but I noticed the fuel gauge and battery gauge are not doing anything.
Can I please get a productive recommendation of things to troubleshoot such as fuses or whatnot? Anything serious and this bad boy is going to the scrap heap as I am sure that it is cursed.
Thank you so very much.
rbridgham is offline  
Old 10-19-2016, 10:14 AM
  #2  
CF Veteran
 
dave1123's Avatar
 
Join Date: Nov 2010
Location: Manlius, east of Syracuse, NY
Posts: 11,288
Year: 2000
Model: Grand Cherokee (WJ)
Engine: 4.0L
Default

My recommendation is to take the PCM to someone and get the power supply tested. There's an internal power supply stage for the 5 volts for the electronics. You may have damaged it with the reverse polarity or triggered a fail-safe function.
dave1123 is offline  
Old 10-19-2016, 10:52 AM
  #3  
CF Veteran
 
Jeepin'_Aint_EZ's Avatar
 
Join Date: Jan 2012
Location: Ocean County, NJ
Posts: 2,208
Year: 1998
Model: Cherokee
Engine: 4.0L
Default

My question would be, how long/how many times did you crank it with reversed polarity? More than likely, like Dave said, the PCM is how I like my bacon..... crispyyyyy
Jeepin'_Aint_EZ is offline  
Old 10-19-2016, 10:57 AM
  #4  
Senior Member
 
Ender's Avatar
 
Join Date: Mar 2010
Location: Southern California
Posts: 855
Year: 1989 Laredo
Model: Cherokee
Engine: 4.0 Inline 6 Renix
Default

Originally Posted by Jeepin'_Aint_EZ View Post
My question would be, how long/how many times did you crank it with reversed polarity? More than likely, like Dave said, the PCM is how I like my bacon..... crispyyyyy
I second this... bad mistake
Ender is offline  
Old 10-19-2016, 06:32 PM
  #5  
CF Veteran
 
caged's Avatar
 
Join Date: Nov 2008
Location: Northern Ontario, Canada
Posts: 7,495
Year: 1990, 1999, 2000
Model: Cherokee
Engine: 4.0
Default

yep. smell your pcm, i bet it stinks now. you may even see the burnt jelly in there.
caged is offline  
Old 10-19-2016, 07:51 PM
  #6  
CF Veteran
 
Bustedback's Avatar
 
Join Date: Feb 2010
Location: Oroville, CA
Posts: 12,368
Year: 1995
Model: Grand Cherokee
Engine: 4.0 with all of the noise and clatter
Default

Check the fuses.
Bustedback is offline  
Old 10-22-2016, 10:11 PM
  #7  
CF Veteran
 
Join Date: Nov 2015
Location: syracuse ny
Posts: 1,644
Year: 1997
Model: Grand Cherokee
Engine: 4.0
Default

Originally Posted by Bustedback View Post
Check the fuses.
Yep. Grab your DVM and backprobe the fuses in the fuse block under the hood. Make sure everything has voltage that is supposed to first, key on engine off. PCM is sure a suspect but let's do the basics
97grand4.0 is offline  
Old 10-23-2016, 06:37 PM
  #8  
Senior Member
 
94zj318's Avatar
 
Join Date: Feb 2012
Location: Baltimore
Posts: 539
Year: 2002
Model: Grand Cherokee
Engine: 4.0L (AMC) Straight Six
Default

I accidentally fried my '94 ZJ's PCM by doing that, and blew all of the fuses and relays... gotta be careful about what you're doing, you most likely fried your PCM.
94zj318 is offline  
Old 10-23-2016, 09:23 PM
  #9  
CF Veteran
 
dave1123's Avatar
 
Join Date: Nov 2010
Location: Manlius, east of Syracuse, NY
Posts: 11,288
Year: 2000
Model: Grand Cherokee (WJ)
Engine: 4.0L
Default

Don't blame the jeep for a mistake YOU make!
dave1123 is offline  
Old 10-24-2016, 07:06 AM
  #10  
Senior Member
 
NewbJeep's Avatar
 
Join Date: Nov 2013
Location: Jax, FL
Posts: 503
Year: 1998
Model: Cherokee
Engine: 4.0L
Default

Geez man glad you're ok. You may have fried your pcm but at least your battery didn't explode in your face
NewbJeep is offline  
Old 10-24-2016, 07:55 AM
  #11  
CF Veteran
 
caged's Avatar
 
Join Date: Nov 2008
Location: Northern Ontario, Canada
Posts: 7,495
Year: 1990, 1999, 2000
Model: Cherokee
Engine: 4.0
Default

yep, the guy that did that at my shop, used my new TJ to jump his 95 xj. at least he hooked the cables up properly on my TJ. not that it matters, but my jeep still ok. this was many years ago.
it fried his pcm, and blew his buss fuse for his alternator.
you could tell where it blew in his pcm when you take the cover off. it was like toasted jelly and stunk like melted crap.

and yeah, you're lucky the battery held up.
caged is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description: