where to look for ground of electrical system.

[rockymountain]

For those who know where to look to check the ground of the electrical system in the KJ, please let us know. I ask because I have the infamous lights dim when bass hits or anything hits for that matter. When I take off in the dark and my doors lock, the lights dim. It seems the system just can't take much at all as it is. I have a 1 year old Eveready batter from batteries plus. I know, not the best but it is the 800 CCA one. So where's the main ground? I'm thinking that needs cleaned up and redone.

Thanks!!

 

[rockymountain]

I was wrong its the Rayovac battery from batteries plus.


Anyway, I found a little corrosion on the terminals so I cleaned them up. I'll see how it is tomorrow morning. I might get a load test done on the battery too. I'm not too confident about it.

 

[theroofable]

Try to follow the ground cable from the battery to wherever it goes. Cleaning up the terminals may help.

 

[JLRockies]

It's doubtful your ground went bad.

 

[rockymountain]

It's doubtful your ground went bad.

hmmm. well after cleaning the terminals to better than new condition last night nothing has changed. looks like I'm flashing people when my doors lock and the bass hits. Seems really sensitive. I don't have to turn up the radio loud at all before they start dimming. I'm thinking the battery is a POS. I'll check the ground cables still but I don't think its bad either. Could a bad alternator cause this? Maybe I'll just get it checked out if I can't find anything wrong.

 

[Cardhu]

Mine has been dimming lights when using power windows, locks etc since it came from the dealer. I just assumed it was from the sissy battery or the narrow channels that the power windows ride in that i've had widened under warrenty according to the TSB that the motors were fighting against.

Battery is still free of corrosion on terminals etc. Just always did it as long as i could remember. Still on factory battery near 5 years later after 4 harsh winters. Not confirmed that the battery is an issue, was just my guess considering how unhappy the jeep is after nights in -20C or below when not plugged in to the block heater.

If it is a grounding issue I'd like to know which one you beef up if you find a solution.

Addition:
I'm not running any sort of stereo upgrade at all unless you count a sat radio plugged into the cigarette lighter. IE really small additional load. yet still replicates the dimming scenario, yet is probably less prevalent then what is seen with stereo bass kicks. Also haven't done much / any research on it.

 

[rockymountain]

Mine has been dimming lights when using power windows, locks etc since it came from the dealer. I just assumed it was from the sissy battery or the narrow channels that the power windows ride in that i've had widened under warrenty according to the TSB that the motors were fighting against.

Battery is still free of corrosion on terminals etc. Just always did it as long as i could remember. Still on factory battery near 5 years later after 4 harsh winters. Not confirmed that the battery is an issue, was just my guess considering how unhappy the jeep is after nights in -20C or below when no plugged in to the block heater.

If it is a grounding issue I'd like to know which one you beef up if you find a solution.

ok thanks. I'm going to see first if the ground cable needs any help and go from there. When my stock battery was 4 years old I hit a big bump and that did it in. It wouldn't start after I came back to leave. They usually fail without warning.

 

[Jake.Ski]

from previous car audio knowledge its usually your pulling to much power to your amp, thats whats causing your lights to dim when the bass hits. so basically your alternator isnt keeping up with the amps your pulling.

You should run a voltage meter to show how many volts your system is at when running and when you have your system on.

with my car idling with my comp system in i was around 14.4volts. When it hit it stayed around 13.1v and there was no dimming or anything.

I also had a heavy duty alternator, 3 batteries, and 2 farad caps.

But that was pushing over 10,000 watts.

 

[Otter64]

it sounds like the alternator isn't keeping up with the power being used.

 

[rockymountain]

from previous car audio knowledge its usually your pulling to much power to your amp, thats whats causing your lights to dim when the bass hits. so basically your alternator isnt keeping up with the amps your pulling.

You should run a voltage meter to show how many volts your system is at when running and when you have your system on.

with my car idling with my comp system in i was around 14.4volts. When it hit it stayed around 13.1v and there was no dimming or anything.

I also had a heavy duty alternator, 3 batteries, and 2 farad caps.

But that was pushing over 10,000 watts.

Yea I'm hearing ya but even the door locks make them dim. My amp is only about 400 watts pushing a single sub. Nothing to write home about. I think an electric razor would dim the lights at this point.

About 15 years ago I had 3 amps running in a mustang and the lights never dimmed. I think it's just another short coming of the KJ.

 

[Jake.Ski]

run a voltage meter and see how much power your putting out of your alternator.
i have never dealt with a short on a vehicle so i have no clue on that one....

 

[rockymountain]

run a voltage meter and see how much power your putting out of your alternator.
i have never dealt with a short on a vehicle so i have no clue on that one....

With the engine running I get a pretty flat 14 volts at the battery. When I rev it, it blips to 14.2 and then seems to get regulated back down to 14 while maintaining a high rpm.

 

[Jake.Ski]

thats very good, now what does it do when your sub hits or when you flip the lock switch.

 

[rockymountain]

With engine running when sub hits I saw at the lowest 13.6. Power lock made it go to 13.3 once. That was with the lights on. Now when I shut it off that's when it got even more interesting. My battery went from 12.6 to 12.1 in about 10 seconds with lights still on. Messing with the locks made it go to about 12.0 and I thought I saw 11.9 flash for a millisecond.

I think the battery is crap. I believe a battery that's good should stay around 13 volts for a while. What do you think?

 

[ridenby]

Time for a battery,good time to get a much better battery.

 

[Jake.Ski]

Ya, get your battery tested!

 

[rockymountain]

Gonna get one of these.
http://www.sears.com/shc/s/p_10153_...o=5&blockType=G5&prdNo=5&i_cntr=1320424095333


That should take care of it. If anyone is interested, here's a link to a printout to get 10% off. (hopefully it includes the batteries)

http://dealspl.us/sears-coupons/334554p

Too bad I have to wait another week. Oh well, its worth 20 bucks IMO.

 

[Cardhu]

Cool, be sure to update if its significant.

I even notice a difference in speed of putting up widows 2 at a time.

 

[Jake.Ski]

a marine battery will work?

 

[rockymountain]

a marine battery will work?

sure why not. Same cold cranking amps yet it can be deep discharged. Best of both worlds. Its even for the "north" region. PLUS it has extra terminals to hook up all your crap.