Jeep Enthusiast Forums banner

wiring guru's, need your help

3K views 48 replies 11 participants last post by  curt93t/t 
#1 ·
Been fighting an electrical issue for the longest. I am tired of wondering if the car will start or not. If the car sits for more than a day the battery goes dead. I just got a test light and almost half of the fuses that I touch cause the light to come on. I'm thinking the only fuse that should be "hot" is for the radio. Also, does anyone have a diagram of what fuses go to what.
 
#4 ·
Got it thanks, guess the million dollar question is should I have so many fuses be running hot with the ignition off? Here they are:

4-Flasher/Haz
5-AMP
6-Parking lights
7-Int lights
8-Overhead console
9-PWR outlets
17-Inst cluster
18-Trailer
19-Anti-lock
23-Brake switch
24-Fogs
25-ACC (sunroof)
27-Rear fog (shouldn't have anything there but do as it's not an export)
 
#5 ·
No, You should expect to se a 30-60mA total draw, thats normal,
alarm, clock, radio, etc,,,,
Most of this is controled by the BCM, check on fuse for BCM (body Control modul), and maybe more, ex interior light,,,,
Now send me a million dollar thx ;)

Edit: what amps Running on which fuses/circuits???
Pull fuse one by one and messure AMP with multimeter.
 
#6 ·
A lot of your fuses are going to be hot even with the ign. off. Think about it, you can turn your lights on, activate the hazards, ETC. with the ign. off. Just because the fuse is hot does not mean that that is the problem circuit. Get an inline amp meter connected to the battery ground and see how much draw you have. If it is a lot, start pulling fuses until you get it to drop and you will have found the problem circuit.
 
#14 ·
I agree, this is the easiest way to do it. To reitterate, remove the battery ground cable from the battery post. Clip your VOM in series, and go to the DC amp scale. Start with the VOM selector in the highest range (if it is selectable). Switch down the range till you see meter pointer deflection (if its an analog meter) or get a digital readout on the display. If the meter is auto ranging, you don't need to switch anything.

If you see current draw up in the 2,3, 10A range, you have a problem. As michiganmaveric said, start popping fuses one at a time, untill the current flow disappears. It is trial and error, and you need to reference the fuse block diagram, to dig in deeper to the problem, once you 'ballpark' the circuit of concern.

' E-A-S-Y '
 
#7 ·
Another thought, have you had your battery tested? A bad cell in the battery will act like what you are describing.
 
#8 ·
I probably shouldn't say with the ignition off. When I say with ignition off I mean absolutely no pwr is going to them. The lights run separately than the ignition, that's why you can turn them on by themselves. Maybe my logic is off, but I've always been told only items required to have pwr with the car not running (radio and alarm, ECM) draw pwr constantly due to having to store something. Lights only draw pwr when you turn them on. It's not the battery because I have gone through at least 5. If you don't drive the car every day the battery is dead after that day. I will probably go ahead and plug a meter into the fuse sockets. Which side is usually the negative?
 
#9 ·
You are checking the circuits with a test light. The test light only show that voltage is available, not that there is any current flow (draw), this is why I suggested that you get an amp meter hooked up to the ground of the battery.
 
#10 ·
None of them Are negative,,,

Messure at AMP with multimeter between both fuse sockets, amps are always messured inline with the circuits,
Voltage between pos and neg,,,,,
 
#11 ·
I had the stealership take a look at it for $85 and was told it was "a" wiring harness and it would cost me $1,000!!! I would imagine they would have tested the battery grnd, but then again, if they did he should have troubleshot further. The mechanic thought it was possibly the resistor for the blower because it was a different design. Told him that's the new style as the old style melts the connector over time. That and my battery problem started way longer. Let's just say I don't trust this particular shop.
 
#12 ·
I am about to give up on this. I am not talking about TESTING the battery ground!!!!!!!! If you put an amp meter inline in the battery ground circuit it will show you if you are drawing too much amperage. If you are then you can start pulling fuses until the amperage draw goes down and that will tell you which circuit is shorted. From there you can find out which wire harness is bad. The dealer is correct that wire harnesses are expensive. Did the dealer tell you which harness was bad? Good luck.
 
#13 ·
I apologize if I am frustrating you. When I said tested I was meaning checking out the draw. The first battery didn't have enough charge and I had to get a different one for the mechanic. With that said, one would think that they checked for draw. He didn't say which harness, I was out of state and talked to him over the phone.

He mentioned the blower fan staying on, which it didn't do that prior, and even if it did stay on I had this problem longer. Then from there he brought up the resistor and I told him that was Jeep's fix to the old one. After that he talked about $1,000 to replace the harness. I came back the other day and went to talk to him, but he's on vacation. I'm going to see if I have draw and if I do start pulling fuses.
 
#15 ·
Well, when I plug the fuse for slot 7,8 and sometimes 17 the meter jumps up. It would go to around 20 on the digital read out. I imagine all of these are lumped together onto the same harness. Fuse 7 is for interior lights, is there anything else in that block? I have the interior lights off, so unless a bulb is on it shouldn't draw pwr (or maybe grounding out??). I thought it might be because the drivers door was open. I tried to unplug the connector at the door and couldn't get it off. Is there a trick after you pull out the red tab? Normally all you have to do is pull the plug off, but not this one! I just went ahead and shut the door and still had a draw.
 
#24 ·
Fuse 7 is for interior lights, is there anything else in that block? .
There are a lot of other things powered off fuse 7 from the junction block. See above post and when you find which fuse in the junction block is causing the problem let me know and I will look it up in my service manual.
 
#19 ·
also, a great point already made is that a battery has six 2.1 volt cells. If one cell "goes bad" is will drain the other 5 cells, trying to "equalize" with them. This will cause a dead battery after some time.

Maybe if you cant perform the proper current test, remove the battery completely from the car, charge it up over a day, and then let it sit for a few days and test it then.

a battery can still measure 12.6 volts and not have enough current stored to turn on a light, or start a car for that matter.
 
#22 ·
This is true, but not the case here. If a cell or cells were shorted, you would not be able to read the current draw. The current draw would be between the cells. The OP is getting a draw outside of the battery. A few quick things to check would be find out what fuses 7 & 8 feed, check to see if the horn works, sometimes people will disconnect the horn when it gets stuck on. Well this will silence the horn but the relay still stays pulled in. And lastly with the key off, see if the field coil of alternator is energized by placing a piece of metal (ferrous) at the end bearing. If its energized, the metal will be drawn to it. Good Luck.
 
#20 ·
one final thought from me... You mentioned 5 batteries have acted the same. Have you had the ALTERNATOR tested? At your battery posts, volts across the + and - should be 14.6 volts. If its less than 13, your alt is not charging the battery and it will go dead in a matter of time while driving around.
 
#21 ·
I did TWO posts ago! I removed all fuses and installed them one by one. With fuse 7 and 8 installed the reading at the battery is at least 20-30!!! Everything else is .03. Once I remove fuse 7 & 8 the reading at the battery goes down to .03. Sometimes the cluster fuse has a reading of around 30, but eventually drops to .03. So those two fuses have to be causing the draw.
 
#23 ·
According to my 2004 shop manual fuse 7 & 8 supply power to the junction block under the dash on the drivers side. Get some help here. Put all the fuses in under the hood, then while your help watches the meter start pulling the fuses from the junction block until the reading drops. When it drops that is the problem circuit.

EDIT: Did the reading go up with just one of the fuses, 7 or 8, installed and not both?
 
#28 ·
EDIT: Did the reading go up with just one of the fuses, 7 or 8, installed?
Yes, with both installed reading is at its highest. Tried this again by myself as I don't know where my father-in-law got the original numbers he read off to me. With all the fuses in I'm reading 6.08 (pic 0523131524). If I take #8 out it goes to .46. If I take 7&8 out it goes to .28 (0523131525). These values were a little bit higher as the battery was getting drained as I pulled the AC controls out to gauge the readings. It went down to .13 when I disconnected it. I noticed the motor running after the ignition was off for a bit. Weird thing is that at that point with the leads hooked up the fuse box was making a noise and I could feel it vibrate.

Going to let the battery charge up a bit and check out a couple more things. To WJChris, thanks for the inputs, but when it's cranked it goes to 14 on the gauge and it runs for hours, so it isn't the alternator. It's only when it sits for a day that the battery dies. Also, a little history, the interior lights would come on intermittently so I have the switch on the column turned off. As stated before, with the switch turned off and no bulbs coming on I shouldn't be drawing any juice right? I have a stealth and have the bulb removed from the hatch area and can leave that thing open for days and it cranks no problems.
 

Attachments

#25 ·
Just curious, what year WJ are we dealing with here and what model. How is it equipped, sunroof, fog lights, ETC.

EDIT: Where are you located?
 
#27 ·
car5car said:
I check resistance.
Remove cable from battery and check voltage. Leave it disconnected and check voltage in the morning.
^^^What the H will this help or tell you?
???Resistance? Wtf,

OP will have to check with a multimeter set at AMP wired inline with every curcuit/fuse and report back what hus readings Are, without That or with just nymbers like 20, 20 what???
A mA or what??? If OP dont do as ppl recomend its imposible to help him out.
 
#29 ·
OP will have to check with a multimeter set at AMP wired inline with every curcuit/fuse and report back what hus readings Are, without That or with just nymbers like 20, 20 what???
A mA or what??? If OP dont do as ppl recomend its imposible to help him out.
The only position that a mA is to test 9V batteries. I have it on the 10A setting. I may have to get a better meter by what you are saying.
 
#30 ·
It looks like the major drop is with #8 taken out. Fuse #8 goes to the ignition sw. for the the accessories and starter functions. It supplies power to fuse #28 and #29 in the junction block, and CB #1. Pull them one at a time and see what happens. Possibly fuse s #22, 12, 21 and 32 also. Have to go for now will get back after dinner.
 
#31 ·
So install fuse #8 and pull 12, 21, 22, 28, 29 and 32 from the main fuse block one at a time and see if anything changes. When you say CB #1 you mean the one with the arrow in the pic? Also, the internals of the ignition are bad as I can pull the key out in any position. what affect would this have on my issue? I don't know how long it's been like this as it's my wife's car.
 

Attachments

#32 ·
With the internals of the Ignition Sw being bad I would start by changing that first, as fuse #8 in the PDC supplies power to the ign. sw.
 
#33 ·
curt93t/t said:
So install fuse #8 and pull 12, 21, 22, 28, 29 and 32 from the main fuse block one at a time and see if anything changes. When you say CB #1 you mean the one with the arrow in the pic? Also, the internals of the ignition are bad as I can pull the key out in any position. what affect would this have on my issue? I don't know how long it's been like this as it's my wife's car.
Might be a short in your ignition switch, That makes the draw, just saying,,,

Disconect the ignition switch from harness, then recheck draw, if Good, thats your pulprit.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top