Help required Fuse 39 keeps blowing

[The Big Boulonnais]

Just a quick comment...

This thread is all that is great about JeepKJ Country. Billwill, you've offered great detailed advice to The Big Boulonnais just because you want to help out a fellow Jeeper. Cheers, I'm gonna toast you with a pint tonight :favorites13:

And Big B, I hope you get these electrical gremlins figured out if for no other reason than the satisfaction of getting it done with a Jeeping partner from the southern hemisphere. Enjoy your time in Wales - the homeland of my grandfather! :waytogo:

Bob

Hi Bob,

Thanks for your coments. You are absolutely right Mr WillBill is a real Gentleman and I am very grateful that he spends his time trying to sort out my troubles.

I had a really awesome time in Wales!! I will go back !!

Cheers,

Chris

 

[The Big Boulonnais]

The Dark Blue wire carries +12 volts to the Reverse Switch as well as to the Hazard Switch. The other side of the Reverse Switch is a White/Gray wire going to each rear Reverse lamp. This Dark Blue wire must not have a direct short to ground.

I would disconnect first connector C1 then connector C3 (8W-12-25) on the Junction Block to see which of the Dark blue wires is going to ground. The Junction Block is basically the internal fuse panel.

Then if needs be cut the faulty wire two inches away from the connector ie. Pin 38 C1 or Pin 32 C3. You can always re-solder the wires back together and insulate with heat shrink tubing.

I will have alook for the connector at your transmission that has the Brown/White wire.

Here are the diagrams:

Hello BillWill,

I am sorry to leave you without any news for such a long time. I came back from Wales on Monday 22nd and went back to work that week so I didn't touch the Jeep. I never had the computer connected to the jeep like I wanted to because my friend damaged his knee so he's off work at the moment.

On Friday I received my new UCA from JBA in US so I spent my weekend to fit them and started to tackle the replacement of all the Lower Arm Bushings and ball Joints. To be honest with you I needed to get away from that electric "Gremlin" like Bob called it because it was starting to go on my nerves.

Anyway this week I work on nights so I had a go at it yesterday afternoon and I can confirm that you were absolutely right. Once the two Connectors are disconnected from the Transmission I fitted a new Fuse, turned the ignition to ON and the fuse held on so I activated the stalk and the indicators lights were working fine!!

So as you mentioned in your last post I tried to locate the Dark Blue wires that go into the Junction Box at Fuse 39.

You are right about disconnecting Connecter C1 pin 38 then if no joy Connector C3 Pin 32 to measure which wire is going to Ground but rather than a long winded explanation I enclose some pics I took this afternoon to show you why I am now a bit baffled.

There is no marking on the Top Connector that goes to the Junction box to tell which wire is which. I tried to pull one wire out of this connector but in a nice way as I am worried to force and break something and so far I couldn't get any wire out.

If I can't take the wires off from the Junction block I'll have to follow all their course from the junction Block to the switches under the Transmission but I can tell you now this is going to be a hell of a job because the harnesses that leave the junction block are huge.

Any other idea very welcome.

Chris

 

[Billwill]

Hi, Firstly are you looking at the circuit diagrams 8W-80-66 to 67 to see how the pins are laid out?

If your question is "how do I pull out the wire from the plug without damaging it?" the answer is as follows:

I have not personally examined this plug in question but these type of plugs basically have the same thing in common in that each of the metal connectors at the end of the wire have a "barb" pressed out of the metal that makes up the contact. This is much like a "barb" on a fish-hook that angles back so the fish cannot slip off the hook.

You need to take something small like a very small Jewerlers' screwdriver and slip it carefully down each face of the contact to see if you can find this small "barb" that is facing back towards you and is latching onto the the plastic housing thus preventing the contact from pulling outwards. Then carefully move this "barb" section back into the metal it was pressed from while gently pulling on the lead. The lead should pull outwards and you will see how the "barb" works. Before pushing the wire and contact back in place after your diagnosis slightly pull this "barb" tab out a bit to spring-tenshion again it so that the "barb" will latch back into place.

If you pull ******* the wire without releasing the barb the barb will fold back on itself....if you are very lucky you can unfold this small piece of metal back to its original possition with it snapping off! If it does snap off you will have to glue the assembly back into its slot with a strong epoxy glue. If you cannot get the pin out you have to cut the wire about two inches back and then slip some small heat-shrink insulation over the lead, solder the wires back together again when finished and slide the insulation over the joint and heat gently...not as good as pulling the contact out intact but will do the trick.

It is difficult to try trace the actual wire inside a thick harness to see where it is actually fraying down to ground.

You need to try isolate the suspect section of wire between two connectors...you will see that these two suspect wires go through various connectors such as C100, C105, C201 etc. If these other connectors have "round" pins as appossed to "flat" pins then you nee a special tool to push the "barb" out of the way so as to pull the pin out. This special tool is a thin tube just large enough to fit over the male or female round pin and is then able to collapse the barb out of the way.

Once you have isolated that the wire is bad going between plug "A" and plug "X" then if the wire dissapears into a major harness that runs around the whole chassis/engine bay..the best thing to do is to physically cut this bad wire off at both ends and tape it out of the way. Now run a completely new section of wire...nice if you can get the same colour...from point "A" to point "X" and neatly connect the ends up and tape over the new wire with black insulation tape. I note that the circuit diagram shows our suspect wires to be "Dark Blue" while the pin-outs of the connectors in the circuit diagram shows these wires to be "Dark Blue/White"....there are often errors like this in these diagrams!

I had to isolate about 6 wires on my Jeep in this way as the harness went from the ECU area on the LHS and traveled in a clockwise direction under the radiator through metal chassis beams to appear again at connectors near the air-filter and hence to the fuse box under the hood...a distance of about 6 feet to connect two points together that are actually about 18 inches apart! I marked my changes on the relevant circuit diagrams and keep those diagrams in the glove box for the next owner of this jeep to find!


Edit to add: You originally picked up this problem after switching over between two batteries using a switch-over switch......have you tried switching back to the original configuration ie. back to the original battery?

 

[The Big Boulonnais]

Hi, Firstly are you looking at the circuit diagrams 8W-80-66 to 67 to see how the pins are laid out?

If your question is "how do I pull out the wire from the plug without damaging it?" the answer is as follows:

I have not personally examined this plug in question but these type of plugs basically have the same thing in common in that each of the metal connectors at the end of the wire have a "barb" pressed out of the metal that makes up the contact. This is much like a "barb" on a fish-hook that angles back so the fish cannot slip off the hook.

You need to take something small like a very small Jewerlers' screwdriver and slip it carefully down each face of the contact to see if you can find this small "barb" that is facing back towards you and is latching onto the the plastic housing thus preventing the contact from pulling outwards. Then carefully move this "barb" section back into the metal it was pressed from while gently pulling on the lead. The lead should pull outwards and you will see how the "barb" works. Before pushing the wire and contact back in place after your diagnosis slightly pull this "barb" tab out a bit to spring-tenshion again it so that the "barb" will latch back into place.

If you pull ******* the wire without releasing the barb the barb will fold back on itself....if you are very lucky you can unfold this small piece of metal back to its original possition with it snapping off! If it does snap off you will have to glue the assembly back into its slot with a strong epoxy glue. If you cannot get the pin out you have to cut the wire about two inches back and then slip some small heat-shrink insulation over the lead, solder the wires back together again when finished and slide the insulation over the joint and heat gently...not as good as pulling the contact out intact but will do the trick.

It is difficult to try trace the actual wire inside a thick harness to see where it is actually fraying down to ground.

You need to try isolate the suspect section of wire between two connectors...you will see that these two suspect wires go through various connectors such as C100, C105, C201 etc. If these other connectors have "round" pins as appossed to "flat" pins then you nee a special tool to push the "barb" out of the way so as to pull the pin out. This special tool is a thin tube just large enough to fit over the male or female round pin and is then able to collapse the barb out of the way.

Once you have isolated that the wire is bad going between plug "A" and plug "X" then if the wire dissapears into a major harness that runs around the whole chassis/engine bay..the best thing to do is to physically cut this bad wire off at both ends and tape it out of the way. Now run a completely new section of wire...nice if you can get the same colour...from point "A" to point "X" and neatly connect the ends up and tape over the new wire with black insulation tape. I note that the circuit diagram shows our suspect wires to be "Dark Blue" while the pin-outs of the connectors in the circuit diagram shows these wires to be "Dark Blue/White"....there are often errors like this in these diagrams!

I had to isolate about 6 wires on my Jeep in this way as the harness went from the ECU area on the LHS and traveled in a clockwise direction under the radiator through metal chassis beams to appear again at connectors near the air-filter and hence to the fuse box under the hood...a distance of about 6 feet to connect two points together that are actually about 18 inches apart! I marked my changes on the relevant circuit diagrams and keep those diagrams in the glove box for the next owner of this jeep to find!


Edit to add: You originally picked up this problem after switching over between two batteries using a switch-over switch......have you tried switching back to the original configuration ie. back to the original battery?

Hi BillWill,

That was another couple of days with no news from me but this time........
I cracked it !! Thanks to you !!

I did like you said but I couldn't get my head round the disconnection of the wires going to the junction block. Too tricky if I get it wrong. With buildings electricity no problem but with Auto electricity I intend to worry to get things worse than I found them.

So I made a temporary connection to the + of the battery with one 10 A in line fuse to the faulty blue that I just had cut 5 inches away from the reverse switch. The reverse lights went on when I passed the gear lever in reverse and I also tried the indicators at same time and everything worked. So I made my mind up I would isolate the faulty blue wire that I cut and I would run a new wire from another 10 Amp Fuse only used for this supply.

I did the job this afternoon in about 1:30 hr from the time I made the test to the time I finished.
I know this +12v supply doesn't come from the ignition switch so if I was going to park in reverse and leave it like this the reverse lights would stay on but it's me who fitted it and it's me who drives the Jeep so this is not going to happen. And to be honest I always park with the 1st gear on but never in reverse anyway.

I picked the 12 v supply from a junction box that I had fitted 6 months ago for my roof lights there was in there a 6 fuses box with 2 spares so it didn't take me long to run not a single wire but a 2 wires insulated cable from that junction box located on the left panel on footwell of my passenger as it's a RHD. That would be be the driver side in US but not sure in South Africa though. Anyway from there via the engine bay down to the Transmission switch. The faulty wire now double isolated with heat shrink sleeves. All properly fitted with cable ties. If that fuse was blowing again I now know straight away where to look.

So I owe you a really big thank you for your time and efforts to help me. You went to find electric diagrams that I never knew existed !! Now I've got a far better understanding of how the electric runs on my Jeep and that's because you pointed me to those diagrams with clear explanations.

I wish one day I could be of help to you but in the meantime as a good French man I say : Merci Beaucoup Mr Billwill !!

Chris

 

[Billwill]

Always a pleasure to help...glad you got it working!


What goes around comes around...one day someone on this board may help me with some major problem!

 

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i had a weird issue where my signals didnt activate from the multifunction switch and reverse lights didnt work. but hazards worked. no one could figure it out. my mechanic found fuse 39 went but still had signal issues and i wasnt gonna pay something craycray for a diagnostic. i traced it to the wire harness going to my reverse switch near the transmission. the harness was not tied down to anything and drooped on to the front drive shaft. that eventually rubbed right through all but 2 wires. wire connectors and crimp tooled back together. not saying its the same but its a shot.

I have the same problem on my 2004 Jeep Liberty. How did you access the wire harness? Under the hood?

 

[[email protected]]

i had a weird issue where my signals didnt activate from the multifunction switch and reverse lights didnt work. but hazards worked. no one could figure it out. my mechanic found fuse 39 went but still had signal issues and i wasnt gonna pay something craycray for a diagnostic. i traced it to the wire harness going to my reverse switch near the transmission. the harness was not tied down to anything and drooped on to the front drive shaft. that eventually rubbed right through all but 2 wires. wire connectors and crimp tooled back together. not saying its the same but its a shot.

I have the exact same problem on my 2004 Liberty Manual transmission. Replaced 39 fuse with 10A red. Signals worked! As soon as I tried reverse, no reverse and no signals.

During the adventure, I tried driving my Jeep to a friend to help end the car was "thumping" and someone suggested it may be the gas filter. So, the frayed wire seemed logical. I just looked and the "dropping wire" has two frayed or compromised wires. I don't have a crimper. Could it be ok to connect them the old fashioned way with electrical tape until I can get it done otherwise?

 

[Billwill]

I have the exact same problem on my 2004 Liberty Manual transmission. Replaced 39 fuse with 10A red. Signals worked! As soon as I tried reverse, no reverse and no signals.

During the adventure, I tried driving my Jeep to a friend to help end the car was "thumping" and someone suggested it may be the gas filter. So, the frayed wire seemed logical. I just looked and the "dropping wire" has two frayed or compromised wires. I don't have a crimper. Could it be ok to connect them the old fashioned way with electrical tape until I can get it done otherwise?

That will do just fine..
A more permanent fix is to cut the wires off, slip some "shrink tubing" over one lead, solder the two wires together, heat up the shrink tubing with a heat gun or hairdryer.

Shrink tubing is a flexable rubber tubing that comes in several diameters...choose one that is slightly bigger than the wires you are joining and do the above steps. It provides a permanent waterproof seal and is how Jeep does the various splices inside the harnesses although they crimp the wires together.

If that does not fix the problem then please get back to us here!

 

[[email protected]]

That will do just fine..
A more permanent fix is to cut the wires off, slip some "shrink tubing" over one lead, solder the two wires together, heat up the shrink tubing with a heat gun or hairdryer.

Shrink tubing is a flexable rubber tubing that comes in several diameters...choose one that is slightly bigger than the wires you are joining and do the above steps. It provides a permanent waterproof seal and is how Jeep does the various splices inside the harnesses although they crimp the wires together.

If that does not fix the problem then please get back to us here!

Thanks! I took your advice and unplugged from the reverse lights switch and my signals worked! And I was able to drive it safely home where I will work on the wires and get back to you on the results.

Another problem arose in the meantime! The window washer fluid was not coming out of the sprayer, front or back. Wipers work fine!

 

[Billwill]

Thanks! I took your advice and unplugged from the reverse lights switch and my signals worked! And I was able to drive it safely home where I will work on the wires and get back to you on the results.

Another problem arose in the meantime! The window washer fluid was not coming out of the sprayer, front or back. Wipers work fine!

You should hear the pump motor running...runs in one direction for front and reverses direction for the rear.

You should hear it running from under the right front fender while someone operates the Multifunction switch.

If not then check the fuses...Fuse 22 on the interior fuse panel most likely culprit.

 

[[email protected]]

Checking that right after work!!

 

[[email protected]]

You should hear the pump motor running...runs in one direction for front and reverses direction for the rear.

You should hear it running from under the right front fender while someone operates the Multifunction switch.

If not then check the fuses...Fuse 22 on the interior fuse panel most likely culprit.

Checking that right after work!!

 

[[email protected]]

I tried the fuse and still no pump. Hope the pump isn't shot! My owner's manual fuel addendum says fuse #22 is for "power sunroof relay, antennae module (export only)"

#32 is for "wipers with front and rear washers" both fuses ok!