I towed my JK for the first time this past week behind my 2004 Itasca Suncruiser, and I had a dead battery at each end of the trip. I am running the Cool Tech wiring harness for tail lights and a Brake Buddy. I turned the key to the first position and pulled the IOD fuse as recommended in other posts on this and other boards. I started the JK engine several times during the trip and let it run for a few minutes. Each time it started easily with no sign of a low battery. However, at each end of the trip only a few hours after last engine test start, the battery was dead. The second time it was profoundly dead, and I had to leave my emergency start battery connected for about 5 minutes before the JK battery received enough charge to start the engine.
In both cases the battery went dead on the night leg of each trip. The battery seemed to stay up for maybe 10 hours during daylight towing but went dead after only 3- 5 hours of night time towing. That seems odd. I wonder whether turning on the motor home headlights triggers some relay in the JK that causes the problem.
It is possible that the problem could have somethign to do with my method of "removing" the IOD fuse. It would come up only so far and resisted complete removal. I assumed that it was designed to be disconnected but stay in above the socket. However, I read earlier tonight in a another post that impplied that the IOD fuse should be removed completely and put in a special docking location elsewhere in the fuse box. Is that correct?
I am also wondering about the ACC position location. There seem to be two separate stops before reaching the full on position where all instrument displays activated. The first position seems to display only the odometer, while the second seems to add another display. The two positions are not very far apart. Are there two such positions near the ACC position, or it this just my imagination? If there are two, which should I use?
If neither of these are the problem, does anyone have any suggestions on what the problem might be? Others seem to have not battery discharge problems with their JKs, but I can't seem to avoid them.
I used to pull the IOD fuse up until it disconnected, but never completely removed it. I never had a problem with my battery discharging. With the engine running, I turned my ignition one click back and towed for hours and never had a problem. If you're doing these two things right, the problem must be in the way you're wiring harness and/or Brake Buddy is set up.
Dan
06 Country Coach Intrigue
07 Wrangler Unlimited Rubicon
My fuse will pull out partially, but it requires a lot of effort to pull it out to the proper "setting" for towing. I mean A LOT OF EFFORT! If you aren't pulling your fuse far enough, you won't get the "no fuse" warning when you try to start the engine. You MUST get the warning!
If your Brake Buddy were cutting in and out - such as when the cigarette lighter plug may be making repeated, partial contact - the compressor will dump and air-up each time power is interrupted. THAT could drain you battery. Also, check to see that the Brake Buddy isn't set too close to the pedal - causing the brake lights to be on as the unit moves about (without the brakes really being activated).
Having a light on or any other current draw will kill the battery over some days. More to the point (and from what you describe), a battery that is repeatedly drawn fully-down will eventually die - which may be an additional problem now that the battery is so resistant to taking a charge.
The Cool Tech harness (which is great and is now offered on Ebay, BTW) wouldn't have any effect unless your Jeep lights were also turned on. My "installer" didn't ground mine properly, and he insisted that the Jeep lights MUST be turned on when towing. He was too smart to read the directions!
If you turn the key to the accessory position and still get a response, then you didn't pull the fuse out far enough. Plus, you shouldn't be able to crank the engine with it pulled out correctly. The accessory position is the first position past off.
fireman50 wrote: If you turn the key to the accessory position and still get a response, then you didn't pull the fuse out far enough. Plus, you shouldn't be able to crank the engine with it pulled out correctly. The accessory position is the first position past off.
That is not true. The engine will crank, you can drive the Jeep with the IOD fuse pulled. This is how they are delivered to the dealer. I test drove a couple with the IOD fuse pulled. You will see NO FUSE on the dash and the radio will not work.
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