Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Main positive circuit short to ground

Thread Tools
 
Search this Thread
 
Old 12-04-2014 | 09:29 PM
  #1  
mike8301's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 73
Likes: 0
From: Denver, CO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.7L Stroker w/ Edelbrock head, forged pistons & rods, roller rockers, BBK TB, Banks headers
Angry Main positive circuit short to ground

I have an '89 good old renix. I was driving and my radio shut off. I checked the fuse, blown. I replaced it and turned the key and it popped immediately. Traced wires back to the main connector where wires go through the firewall all the way to the battery cables. Every power circuit is grounded. I can get a connection from the positive battery to the body. I had noticed a slight power drain and this is clearly why. It doesn't pop any other fuse.. Not sure why.

My question is, what on a renix is a likely culprit. Any help is appreciated. Cruiser54 please help!
Old 12-04-2014 | 11:01 PM
  #2  
cruiser54's Avatar
::CF Moderator::
 
Joined: Aug 2011
Posts: 43,971
Likes: 1,565
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Default

Fuse blown in the fuse box for the radio?

Do you have a manual transmission?

Aftermarket radio?
Old 12-05-2014 | 12:20 AM
  #3  
mike8301's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 73
Likes: 0
From: Denver, CO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.7L Stroker w/ Edelbrock head, forged pistons & rods, roller rockers, BBK TB, Banks headers
Default

Fuse that blew was in the fuse block. Manual transmission, and aftermarket radio. 10 amp fuse in the back of the radio is fine, that entire circuit is grounded out. I traced it through c101 all the way to the battery. with the fuse out the ground is only on the c101 side of the but so far affects everything in the engine bay to the battery cables. Not sure what to look at / for in the mean time.
Old 12-05-2014 | 07:12 AM
  #4  
cruiser54's Avatar
::CF Moderator::
 
Joined: Aug 2011
Posts: 43,971
Likes: 1,565
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Default

Is your fuse box soaked in oil from a leaky clutch master cylinder?

Look here for melted fusible links.
Attached Thumbnails Main positive circuit short to ground-starter-relay-diagram-001.jpg   Main positive circuit short to ground-starter-relay-connections.jpg  
Old 12-05-2014 | 05:58 PM
  #5  
mike8301's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 73
Likes: 0
From: Denver, CO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.7L Stroker w/ Edelbrock head, forged pistons & rods, roller rockers, BBK TB, Banks headers
Default

Originally Posted by cruiser54
Is your fuse box soaked in oil from a leaky clutch master cylinder?

Look here for melted fusible links.
It looks like it is covered in fluid. This is my first 5 speed XJ, what part would I need to replace to fix that? And can I use connector cleaner to get the C101 connector and fuse box cleaned? Also I looked at that box yesterday and noted some corrosion on the connectors, but I didn't note any melted connectors. Though I will do some testing between its positive and ground connections. Thanks for the help. I plan on working on it sunday, If you have any other tips or suggestions, please let me know. For the most part the wiring harness is in near perfect shape for 26 years (mfg 88).

Last edited by mike8301; 12-05-2014 at 06:02 PM.
Old 12-05-2014 | 06:06 PM
  #6  
freegdr's Avatar
CF Veteran
 
Joined: Mar 2010
Posts: 47,923
Likes: 31
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Default

Originally Posted by mike8301
It looks like it is covered in fluid. This is my first 5 speed XJ, what part would I need to replace to fix that? And can I use connector cleaner to get the C101 connector and fuse box cleaned? Also I looked at that box yesterday and noted some corrosion on the connectors, but I didn't note any melted connectors. Though I will do some testing between its positive and ground connections. Thanks for the help. I plan on working on it sunday, If you have any other tips or suggestions, please let me know. For the most part the wiring harness is in near perfect shape for 26 years (mfg 88).
Fuse box is covered with oil on top. Clutch master need to be replaced. mine ended up eating thru the plastic causing fuses to loose contact from connnectors .
Old 12-05-2014 | 07:10 PM
  #7  
cruiser54's Avatar
::CF Moderator::
 
Joined: Aug 2011
Posts: 43,971
Likes: 1,565
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Default

Originally Posted by mike8301
It looks like it is covered in fluid. This is my first 5 speed XJ, what part would I need to replace to fix that? And can I use connector cleaner to get the C101 connector and fuse box cleaned? Also I looked at that box yesterday and noted some corrosion on the connectors, but I didn't note any melted connectors. Though I will do some testing between its positive and ground connections. Thanks for the help. I plan on working on it sunday, If you have any other tips or suggestions, please let me know. For the most part the wiring harness is in near perfect shape for 26 years (mfg 88).
Electrical cleaner is just fine. How's the C100 connector look? It's down below and to the right of the C101.
Old 12-06-2014 | 01:03 AM
  #8  
firehawk618's Avatar
Seasoned Member
 
Joined: Nov 2014
Posts: 290
Likes: 0
From: Marysville, WA
Year: 1989
Model: Cherokee
Engine: 4.0
Default

Originally Posted by freegdr
Fuse box is covered with oil on top. Clutch master need to be replaced. mine ended up eating thru the plastic causing fuses to loose contact from connnectors .

The one I just picked up had this exact same problem.

Fuse contacts all over heated, some melted, fuses themselves very brittle to touch.

My fuse box was destroyed. Every renix Cherokee I found at the junkyard had a mint fuse box.

Spliced in the whole thing, all my electrical problems vanished. This rig had a lot more that DIDN'T work vs DID because of this.
Old 12-06-2014 | 02:08 AM
  #9  
freegdr's Avatar
CF Veteran
 
Joined: Mar 2010
Posts: 47,923
Likes: 31
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Default

Originally Posted by firehawk618
The one I just picked up had this exact same problem.

Fuse contacts all over heated, some melted, fuses themselves very brittle to touch.

My fuse box was destroyed. Every renix Cherokee I found at the junkyard had a mint fuse box.

Spliced in the whole thing, all my electrical problems vanished. This rig had a lot more that DIDN'T work vs DID because of this.
I got my new fuse box Im just gonna remove the buss bars and swap into new front. No splicing that way.
Old 12-07-2014 | 02:23 PM
  #10  
mike8301's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 73
Likes: 0
From: Denver, CO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.7L Stroker w/ Edelbrock head, forged pistons & rods, roller rockers, BBK TB, Banks headers
Default

Update---

I replaced the clutch master cylinder and cleaned both the connection at the firewall, and the entire fuse box. I discovered that the under hood lamp to be the cause for the immediate short to ground at the battery cables. However on the fuse box, I still have a short to ground on the Acc and Radio connections. Does anyone have an idea of what connectors / circuits to test from there? Any help is appreciated. Thanks for the tips so far!

-mike
Old 12-08-2014 | 10:17 PM
  #11  
mike8301's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 73
Likes: 0
From: Denver, CO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.7L Stroker w/ Edelbrock head, forged pistons & rods, roller rockers, BBK TB, Banks headers
Default

This connector was a little dirty.

Name:  ForumRunner_20141208_201647.png
Views: 1349
Size:  418.3 KB
Old 12-08-2014 | 10:17 PM
  #12  
cruiser54's Avatar
::CF Moderator::
 
Joined: Aug 2011
Posts: 43,971
Likes: 1,565
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Default

Originally Posted by mike8301
This connector was a little dirty.

Attachment 260298
The c100 connector......
Old 12-08-2014 | 10:18 PM
  #13  
mike8301's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 73
Likes: 0
From: Denver, CO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.7L Stroker w/ Edelbrock head, forged pistons & rods, roller rockers, BBK TB, Banks headers
Default

I found duct tape in various spots through the wire harness.

Name:  ForumRunner_20141208_201828.png
Views: 1344
Size:  371.1 KB
Old 12-08-2014 | 10:20 PM
  #14  
cruiser54's Avatar
::CF Moderator::
 
Joined: Aug 2011
Posts: 43,971
Likes: 1,565
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Default

Originally Posted by mike8301
I found duct tape in various spots through the wire harness.

Attachment 260299
Little pieces? Normal. Solder and shrink tube those bad boys.
Old 12-08-2014 | 10:22 PM
  #15  
mike8301's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 73
Likes: 0
From: Denver, CO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.7L Stroker w/ Edelbrock head, forged pistons & rods, roller rockers, BBK TB, Banks headers
Default

I sure did. Put a new loom on it and rewrapped it all. Only have to track down the radio positive wire and what is grounding it. I know that the cigarette lighter, intermittent wiper module and radio uses that circuit. Any others to check? Thanks again.


Quick Reply: Main positive circuit short to ground



All times are GMT -5. The time now is 01:41 PM.