2nd Gen Non-Engine/Transmission Charging System issues

[greyghost]

After reading over a 100 posts on battery and charging issues I haven't found the solution it was looking for. I'm having a battery charging issue. I found it after installing aftermarket headlights and wiring harnesses.



I've installed the wiring harnesses from SUVLights.com which by the way work extremely well and are a huge improvement over the stock lighting. Each headlight has its own harness and is wired directly to one battery, driver side headlight to driver side battery and passenger side headlight to passenger side battery. Each headlight is controlled by relays.



Now for the charging system, I have notice over time my passenger side battery would get weak. I would make it a point every Spring and Fall to rotate the batteries, swap positions. I found this to work but had no idea how bad the one battery was getting.



After making the swap the passenger side battery is dieing the slow death. The headlight is much dimmer than the driver side. I've been watching this for the last 2 months. This morning the passenger headlight was almost completely out. Hardly any light being emitted by the elements, even during higher RPMs (Higher Alternator Output) the light intensity would not change. I've cleaned terminals, change the terminal to larger more robust ones, went to a DC multi-fine strand welding cable for the “cross cable” from battery to battery. Made sure the grounds are good (think of taking another cable from the ground post back across to the other battery's ground post).



So basically is there anyone who has a fix to making sure each battery is getting re-charged equally. I think I'm stuck doing the battery two step and getting new batteries. I've had the truck 10 years and 210,000 miles, this is the second set of OEM batteries they are 2 years old.



Thanks in advance for any thoughts or ideas



Garrett

 

[DPellegrin]

Garrett, I would like to suggest that you get yourself a jumper wire large enough to carry the current of your super headlights with alligator clip and jump around the relay-headlight directly to the battery. The fact that the batteries are good enough to start the truck and just one headlight is very dim means to me that the relay feeding that headlight is bad or ground connection is bad. You have high resistance in that circuit somewhere.



Your charging system issue with just one battery running down is puzzling as well. Both batteries are wired in parallel (positive-to-positive, negative-to-negative) to the starting/charging circuit. So the charging system does not know that there are two batteries being charged. It just knows that there is 12. 6volts out there. The charging voltage should be about 14. 0 volts at 60*F. If there is is one battery going down and you are certain that all the wiring is good and connections are good then it is a battery issue.



Regards,

 

[GAmes]

And it is possible you bought a bad battery. It happens. Have you had the low charge battery tested for an internal short? Does the gauge in the truck always read low as if the grid heaters are on? Have you tried hooking both headlights to the "good" battery?



FWIW, I have never swapped my batteries around. Current batteries are over 5 yrs old.

 

[RStankevitz]

even if that battery was bad the light would still light as there are huge battery cables tying them together i would say that either the positive cable is bad or the ground cable on that battery is bad.

take a set of booster cables and just connect the 2 positive terminals together and see if light brightens up if not try jumping both ground terminals together my bet is the ground cable on that battery isnt making a good connection to the block thus not letting it charge

 

[greyghost]

DPellegrin, GAmes, RStenkevitz

Thanks guys for your time and advice.



Let me start by saying it's fixed. I feel a little dumb here. I let a buddy borrow the truck for little over three weeks just after I did some maintenance to make sure the truck was “good to go”a few months ago. He helped some guy by giving him a jump and thought he had to disconnect the second battery (?). But in the process he had screwed up my main battery connector and cable (I should have taken pictures). Anyhow, I took what DPellegrin and RStenkevitz had suggested and started there. Once I got to the bottom of things, I was able to get everything working. Something GAmes had mentioned about a bad battery so I took the batteries back to the Dealer (OEM battery) and had them tested. Bad cell in one battery is what the tech told me, not sure if the damage was there all along, might have been? Now I have two new ones.



I was getting frustrated and couldn't see the forest for the trees. Thanks again for your help guys.



Respectfully,



Garrett

 

[DieselDoghouse]

Glad to hear the problem's solved for now. Just in case the bad cell was effect not cause I would carefully test the positive strap cable—having 2 batteries with different personalities bothers me…Like R. Stankevitz touched on, with a heavy cable between them (or not???) it should be 'me and my shadow'.

 

[greyghost]

DieselDogHouse

Man, as soon as D. Pellegrin chimed in the fog cleared and I realized all the little things that I wrote made this thread unnecessary. I’m sure most of you guys were think WTH.



I forgot to think of all those cable as one big bus bar and the system should act like one 1500 CCA battery. But here’s to all gettin’ me back on track.



The “cross cable” was the problem, right at the connection to the main driver’s side battery terminal. Messed up like a soup sandwich. Now from positive battery post to positive battery post I have less than 2 ohms. I’m going to watch it and see how time, corrosions, etc. effect this.



“Me and My Shadow” that’s awesome. LOL





Garrett

 

[DPellegrin]

Garrett, Glad to have helped. Hey I been there! Some times you look at something so long you miss the obvious.



Best Regards,