Jeep Commander Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter #1
This 2008 has had a number of electrical challenges.

The screen on the audio system is doing strange things. It works on and off and the display goes haywire. It also sounds like a small cooling fan is running with a mind of it's own. The other problem is that the heater vent fan sounds like it has an obstruction. I found a mouse nest in the glove box and I suspect that the mice have also blocked the fan.

If I pull the fuse to the audio system and the vent fan, will this cause any other problems? I was told that this could affect the main computer somehow. The Jeep wouldn't start Friday night and it came back home on a flat bed truck. The next day it started normally. It's time to address these electrical problem, I don't want to get stranded like that again.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #2
Yesterday I had my first look under the dash. I located the fuse box and tried to pull the glove box out. I doubt that pulling the audio fuse and the blower fan fuse would have any afect on the engine control module, but that's what I was told.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #3 (Edited)
I know it's not probable that the fan and audio circuits would affect the ECU, but that's what I was told.

From the interior fuse panel, I pulled the 30 amp fuse in position 1. That's the audio head unit according to the owners manual. But when I turned the key to start the engine, the touch screen still showed the time and the word Jeep. Is the touch screen is on a different circuit?

From the power supply fuse box under the hood I pulled the fuse for the blower fan. The fan was getting power whne I turned the key, even with the dash fan switch in the off position. Removing that fuse seems to have solved the problem. The power supply to the back right fuse box, shown in image with an open lid, has some corrosion.
40736


Here is the corroded power cable. I'm guessing that maybe it's causing my no start problem.
40737
 

·
Registered
Joined
·
20 Posts
Discussion Starter #4 (Edited)
I unbolted that corroded connection (the above pic) and all that green oxidation was just some shallow pitting. It didn't extend down into the crimp. I wired brushed it clean and pulled some of the black electrical tape away. It looks like the crimped connection is "potted" in resin (golden color under the black tape.) Might be good for a long time.
40738


I removed every positive cable from the battery post, to the middle fuse box, and to the back fuse box. Scrubbing everything and sprayed with contact cleaner.
40739


The positive battery post hardware looked bad. But the oxidation brushed off and the crimp looks solid.
40740


This ground strap was in bad shape. The strap comes from behind the left side of the engine and bolts to the top of the firewall. Maybe 20 percent of this strap remains unbroken. Correction, it disintegrated.
40741
 

·
Registered
Joined
·
20 Posts
Discussion Starter #6 (Edited)
Climbed under the Jeep in the freezing rain in order to find the other end of the main engine ground strap. But then I found it at the back of the intake manifold,,,up top. Changed into dry clothes. Is there a good alternate location on the engine to install a new ground strap? The factory bolt location looks impossible to access.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #7
I've been reading that that engine ground strap is only to reduce radio noise. That's not my problem. I have a No Crank.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #8 (Edited)
I'm looking to pull the fuse for the stereo touch screen. The owner's manual lists a "Flipper Glass" fuse in cavity 17. Is that the touch screen?
 

·
Registered
Joined
·
20 Posts
Discussion Starter #9 (Edited)
I put the battery on my charger. It read 50%; 10 minutes later it was at 75%. I went to WalMart and when I got Home it was 100%. After reinstalling the battery, the Jeep did start. But on the first turn of the fob the starter didn't engage. I wiggled the fob around in the ignition switch and the starter caught briefly; I tried again and it caught all the way.

It's about 40 degrees today. Much warmer than when the problem started. Hard to understand what's going on. Weak battery, worn out ignition switch, or a temperature dependent electrical connection.

Right now the plan is to wait until it won't start, and then I'll wiggle the heck out of the ignition switch.
 

·
Super Moderator
Joined
·
5,843 Posts
I', looking to pull the fuse for the stereo touch screen. The owner's manual lists a "Flipper Glass" fuse in cavity 17. Is that the touch screen?
 

·
Registered
Joined
·
92 Posts
On the first turn of the fob the starter didn't engage. I wiggled the fob around in the ignition switch and the starter caught briefly; I tried again and it caught all the way.
Hey GF - take a look at my recent post regarding your funky start connections - specifically your wiggling of the fob...

 

·
Registered
Joined
·
20 Posts
Discussion Starter #12
I read through your post bp73 and added it to my bookmarks. That's a lot of good info.

I pulled the Jeep out of the driveway and into the garage. There, I'll climb under and try to find the starter in order to see the condition of it's wiring. I used a telescoping inspection mirror to look down from the top of the engine bay, but I didn't see a starter. Can it be inspected from the bottom?
 

·
Registered
Joined
·
20 Posts
Discussion Starter #13 (Edited)
I checked out that link about the junction block. I'm starting to think that mine needs to be replaced. Strange electrical things happen like, after parking and turning off the engine sometimes the rear window wiper will activate as your walking away from the Jeep . I think the relay is in the JB. That's always good for a laugh.
 

·
Super Moderator
Joined
·
5,843 Posts
If you take a good look at the information in that junction block sticky thread, most everything electrical runs through, or, has a fuse in the junction block; It could also just be a short or ground somewhere in the electrical system, which can be a real P.I.A. to track down & isolate.
 
1 - 14 of 14 Posts
Top