Annoying battery issue

[Three Bravo]

Gents, you all have been great here on my previous posts, so I would like to post again. Full disclosure I am no backyard mechanic, but I can handle simple stuff, but I would appreciate some guidance in the hopes I can squash this before taking it to my friend and spending some money.

My 99 has some battery / cable issues. It has a drain somewhere, that if I leave it ~48hrs she will not start. Trickle charge it, good to go. In the meantime I have simply taken to disconnecting the primary battery's neg term when it sits. due to my work schedule, it can often be a week before I drive it.

that is not my pressing issue. lately, it takes considerable effort to get the thing to turn over. battery disconnected, it sometimes will not start when I re-attach the cable. fuel pump runs, interior lights work, it may give a dead single "click" or turn over like it is dead before giving out. Sometimes I have to fiddle with the stupid cable 7 times before she turns over. lock it down. next time I go to turn her over... same symptoms. more fiddling to get it to turn over. I do not understand how I can go from cranking, locking it down, driving to my destination, and it once again gives same issues. when nothing has changed i.e. cable position. sometimes it fires cranking the cable all the way to the left. next day, cranking and turning all the way to the right. some days, the middle is the sweet spot. there is just no consistency.

this past winter I cleaned up all terminals, connections, etc. ground down the connectors to make them attach tighter. this is a new issue, in the past, she'd be good all day long. now, I need to fiddle with the thing every dang time I stop it and it is getting very tiresome, especially in this heat. If I can get it to start 2 times in a row it is a blessing. any ideas on what to look at?

Thanks in advance... Mike

 

[BSeyler]

I spent a lot of time chasing a battery drain on my’99. It was an ST model, so no glove box light, etc. It turned out to be the seat belt module, that is supposed to cut the power to the seat belts a set time after the pickup was shut off. They are no longer available.
So, I got in the habit of pulling the IOD fuse every time I shut it off. I was going to rig a relay from the ignition, but didn’t do it before I sold it.

 

[Three Bravo]

I spent a lot of time chasing a battery drain on my’99. It was an ST model, so no glove box light, etc. It turned out to be the seat belt module, that is supposed to cut the power to the seat belts a set time after the pickup was shut off. They are no longer available.
So, I got in the habit of pulling the IOD fuse every time I shut it off. I was going to rig a relay from the ignition, but didn’t do it before I sold it.

I just ran outside, I have a "Laramie SLT" trim. what that means beyond it is nothing like current laramies is beyond me. I have a creeping feeling it may be the radio, but again, have not looked into that. I am more concerned with the daily tooling just to start it at this point. I backed it up earlier to power wash a car and some stuff. went to pull it back forward earlier, wouldn't start. hell with it. deal with it in the morning. it's getting old.

 

[BSeyler]

In the morning, when everything is cooled down, pull the seat belt out a way and see if it’s warm to the touch. If so, it’s your seat belt module keeping the power on.

 

[Three Bravo]

In the morning, when everything is cooled down, pull the seat belt out a way and see if it’s warm to the touch. If so, it’s your seat belt module keeping the power on.

I will do just that. but that wouldn't explain this other issue I am having would it?

 

[petersonj]

I will do just that. but that wouldn't explain this other issue I am having would it?

When it comes to high amperage electrical circuits, there can be many causes for a no or slow crank condition. The starter on your Cummins engine requires over 500 amps to achieve a fast cranking speed to reliably fire the injectors. That is why there are two high capacity batteries.

Things that matter:

* BOTH batteries HAVE to be in good condition. Are they? How old are they? How do you know what condition they are in?
* Electrical connections must be clean and tight. When you check the terminal connection at the battery, are you checking the condition at the location where the stranded copper wire is crimped onto the battery terminal, as well? How about the ground terminal connections at the engine block?
* The starter brushes / commutator and contactor must be in good condition. Is the starter original? rebuilt? When?

A poor connection at any of the above mentioned places will generate heat quickly every time the circuit is energized. Heat immediately changes the quality of the connection - hence, the next time the key is placed in the "start" position, the circuit behaves differently. No mystery there.

It has a drain somewhere, that if I leave it ~48hrs she will not start. Trickle charge it, good to go. In the meantime I have simply taken to disconnecting the primary battery's neg term when it sits.

If I understand correctly, you are only disconnecting one battery? If so, there is no value in doing this. If you are suspecting a drain, then BOTH batteries must be disconnected.

Please give us more history about your truck. Are you the original owner? Or, if not, how long have you had your truck, how many miles on the truck, how many miles and time on components like batteries and starter?

We don't know your electrical skills, but if you have a muli-meter, there are some simple tests one can perform to help diagnose your problem.

- John

 

[Topzide]

@Three Bravo, Get yourself a good smart trickle charger for your truck and make a charge connection that you can plug into your 7 way trailer connector. Their is a constant 12 volt and of course a ground connection in there. That way you can keep batteries on trickle charge without having to open the hood. Could also make it so that it breaks away quickly with a short lead that wont drag on the ground if you forget to unhook or need to go in a hurry! Ask me how I know that! Most of the newer trickle chargers have the 2 pin polarized connector to do wired or clips for charging. Then get a 7 way plug and wire correctly. Much easier to hook up since yyour not driving as much. PM me for more detail if needed. Good we could help with issues. Knowledge is POWER! But I prefer the power of our trucks!

 

[Three Bravo]

When it comes to high amperage electrical circuits, there can be many causes for a no or slow crank condition. The starter on your Cummins engine requires over 500 amps to achieve a fast cranking speed to reliably fire the injectors. That is why there are two high capacity batteries.

Things that matter:

* BOTH batteries HAVE to be in good condition. Are they? How old are they? How do you know what condition they are in?
* Electrical connections must be clean and tight. When you check the terminal connection at the battery, are you checking the condition at the location where the stranded copper wire is crimped onto the battery terminal, as well? How about the ground terminal connections at the engine block?
* The starter brushes / commutator and contactor must be in good condition. Is the starter original? rebuilt? When?

A poor connection at any of the above mentioned places will generate heat quickly every time the circuit is energized. Heat immediately changes the quality of the connection - hence, the next time the key is placed in the "start" position, the circuit behaves differently. No mystery there.



If I understand correctly, you are only disconnecting one battery? If so, there is no value in doing this. If you are suspecting a drain, then BOTH batteries must be disconnected.

Please give us more history about your truck. Are you the original owner? Or, if not, how long have you had your truck, how many miles on the truck, how many miles and time on components like batteries and starter?

We don't know your electrical skills, but if you have a muli-meter, there are some simple tests one can perform to help diagnose your problem.

- John

I am not the original owner of the truck. I purchased in spring of 2019. It has 180k on it. I Have not replaced batteries nor starter. Tests of battery at advanced as well as with my old man last winter showed they were still fine and in good shape. I do have a multi-meter. We did also re-do the terminal wiring so I should be getting a good, tight connection there. I can try to get photos of that later on. what do you suggest I check out with the multi meter?

 

[AH64ID]

Monitor voltage during cranking.

 

[petersonj]

I Have not replaced batteries nor starter. Tests of battery at advanced as well as with my old man last winter showed they were still fine and in good shape.

Since there are no details of how the battery tests were performed, a reliable conclusion cannot be drawn.

Here is what I would do if it were my truck. Fully charge both batteries. Then disconnect the charger and disconnect the ground cable at each battery. Let batteries set for 24 hours. Before reconnecting, check each battery voltage. Battery voltage should be at 12.6 or 12.7. Both batteries should be within less than .1 volt of each other. Record the information.

Now it is time to do as @AH64ID suggests - load test batteries using the starter as a load. Reconnect ground cables to both batteries. Remove fuel pump relay in the PDC (power distribution center). Connect multimeter (setting on manual 12 volt scale) by placing and holding the probes on each post of one battery. This is important - the probes must be on the battery posts - not the clamp. With the transmission in neutral and the park brake set, have a helper crank the engine for 15 second without stopping. Record the lowest average voltage. Wait one minute to cool the starter and then perform one more 15 second test and record the results.

Repeat the same steps for the other battery. During each test, a minimum standard voltage in the automotive industry is at least 9.6 volts for a passing grade. Personally I want to see a minimum of 10.2 volts or higher since two batteries are being used with a healthy engine cranking speed. Both test results should be within .1 volt of each other.

If the engine cranks slowly and and battery voltage immediately falls to minimum voltage or lower, the batteries are a problem.

If the engine cranks slowly (or clicking sound and nothing happening) and battery voltage hardly drops during the test, this will be an indication that the batteries are fine and there is a poor connection problem or a poor connection inside the starter problem (such as a worn contactor or worn brushes).

- John

 

[Three Bravo]

Since there are no details of how the battery tests were performed, a reliable conclusion cannot be drawn.

Here is what I would do if it were my truck. Fully charge both batteries. Then disconnect the charger and disconnect the ground cable at each battery. Let batteries set for 24 hours. Before reconnecting, check each battery voltage. Battery voltage should be at 12.6 or 12.7. Both batteries should be within less than .1 volt of each other. Record the information.

Now it is time to do as @AH64ID suggests - load test batteries using the starter as a load. Reconnect ground cables to both batteries. Remove fuel pump relay in the PDC (power distribution center). Connect multimeter (setting on manual 12 volt scale) by placing and holding the probes on each post of one battery. This is important - the probes must be on the battery posts - not the clamp. With the transmission in neutral and the park brake set, have a helper crank the engine for 15 second without stopping. Record the lowest average voltage. Wait one minute to cool the starter and then perform one more 15 second test and record the results.

Repeat the same steps for the other battery. During each test, a minimum standard voltage in the automotive industry is at least 9.6 volts for a passing grade. Personally I want to see a minimum of 10.2 volts or higher since two batteries are being used with a healthy engine cranking speed. Both test results should be within .1 volt of each other.

If the engine cranks slowly and and battery voltage immediately falls to minimum voltage or lower, the batteries are a problem.

If the engine cranks slowly (or clicking sound and nothing happening) and battery voltage hardly drops during the test, this will be an indication that the batteries are fine and there is a poor connection problem or a poor connection inside the starter problem (such as a worn contactor or worn brushes).

- John

thank you very much for the help. this is easy enough. I seem to have lost my multi meter in the shed, of course. I will be taking it by a friend's shop to diagnose here soon. I have to get the jeep in there first, it has an ignition problem. oh the joys of 22 year old vehicles. I missed it earlier on my maintenance log, but I wrote 7/20 on both batteries, so I did swap both out at that time. Diehard silvers. Thank you again. looking forward to getting the truck back in reliable service. will be putting my front driveshaft back in as well, had it rebuilt.

 

[BigPapa]

Mid-90's Jeep with a 4.0L?

 

[Three Bravo]

Mid-90's Jeep with a 4.0L?

2000 Wrangler sahara with the 4.0
replaced my 95 wrangler. that there was a vehicle I never should have sold.

 

[BigPapa]

Just wondering. We had a '95 Grand Cherokee with the 4.0L and had to replace the coil. I should never have sold it, either....

 

[BK]

I spent a lot of time chasing a battery drain on my’99. It was an ST model, so no glove box light, etc. It turned out to be the seat belt module, that is supposed to cut the power to the seat belts a set time after the pickup was shut off. They are no longer available.
So, I got in the habit of pulling the IOD fuse every time I shut it off. I was going to rig a relay from the ignition, but didn’t do it before I sold it.

I had the same problem twice on my 99 ..
This above, from BSyeler, was exactly one of my problems. There is a box under the center console, seems it has a little ball in it to lock up the belts. It gets stuck. Took the box out, beat it up a bit, seems the ball free'd up and I was ok.
I had another, be the glove box.
Many other times it was me not turning off the interior lights when I left the truck for the night, or left the door not closed all the way. I changed all the interior bulbs to LEDS (including the glove box), and no more issues from my wrong doing.

(my daughter's 2010 jeep, the OEM Stereo AMP wouldn't go to sleep, and it continued to draw about 1amp, would kill the battery pretty quickly)

You can buy a fuse adapter that provides a nice loop to measure current. DC clamp amp meters are fairly inexpensive now a days.. so you can go fuse by fuse to find the drain.
There are some loads that take a few minutes to "go to sleep" and reduce their drain. So if you find a drain, wait a few minutes after removing the key.