2nd Gen Non-Engine/Transmission 0.5amp load on battery

[BK]

I've had a problem with the truck sitting for about 2wks, and not having enough juice in the batteries to start the truck.
Pulled the grounds, put an amp meter in series and found the 0.5mp.

Starting pulling fuses and found that Fuse 12 IOD, of the fuse panel on the left had side of the dash would kill the drain.

Pulled the radio connectors, and CTM/IEM connector, pulled the connector on the glove box light, no change.

I don't have the "high line CTM", so a bunch of things aren't part of the search.


I felt the 0.5amp was just to high, felt is should be 1/10 of that are less.
Thoughts?

 

[BK]

So digging deeper found it also powers the SeatBelt Control Timer Module (SCTM) .

This time, things were a bit quieter on the back yards.
When I pulled the fuse and put an amp meter in it's place, I heard the sound of a relay closing, but not opening, and the current stay at the ~ 0.5 amp.
Pulled the amp meter lead , reconnected, kept doing that and searched for the sound.
It was coming from the top of each of the front seats, where the seatbelt comes out.

Easily found a connector on the drivers side, pulled it, and dropped ~ 0.21amp , took a lot longer to find and get to the passanger seat connector, which was snapped to the frame of the center seat.. finally got that disconnected.

Now down to less than .08amps.
I would think it should be even lower.
I haven't tried to dig the SCTM out yet.
I don't hear another really, but there could some drive on int the SCTM causing a bit more current draw than I think normal..

Anyone have this SCTM go bad before?

 

[BK]

Disconnected the SCTM, bought another 10ma (0.010amps) ..
Down to .080ma of drain through Fuse 12.
(all during this the door jam switches are forced closed and the glove box bulb connector is pulled, pulled the plug on the under hood lamp, and the aftermarket alarm system was pulled before all the tracking down of the parasitic current).

Does anyone know what the normal parasitic drain on a 99 or so ?

Googling the SCTM, seems it's a common failure.

 

[BK]

After doing some more reading, other suggested waiting for a period of time for other modules or items to time out.
After a minute or so, the 80ma turned into about 2ma.
The bulk of that 80ma was the halo light on the ignition switch.

So now I'm sure the SCTM has been bad.

I remember for years hearing a relay come on when I entered the truck, haven't heard that for a little while now...must have been these seatbelt relays / solenoids I was hearing...

 

[JMcCoy]

I looked into it myself, when tracking down a battery drain. About a year ago, there was a nationwide backorder on the SCTM. Fortunately my drain turned out to be the lamp the under hood.

 

[BK]

thanks for the reply.

While I was looking, I had the SCTM unplugged, and when I couldn't find one I figured let me try it again.

Turned out once I left the SCTM sit unplugged for a while, and retested, it's acting ok (for now) (Seatbelts locked after ~ 30mins).

I found one dealer on line showing stock @ 135bux.

So long as I keep hearing the relays when I get in, I should be GTG.

 

[rotohead]

Very interested in this thread as I've been trying to figure this drain for a few years and my hearing isn't nearly good enough to hear any relays to help me track this problem. I've tried also to routinely hook up trickle chargers to the batteries and that seems to get the batteries up to proper charge but screws up something either in the PCM or elsewhere that causes the torque converter to lock/unlock. Then the only way to fix it is to disconnect the batteries for a period of time, reconnect them and set the ECM (cycle to gas pedal routine three times). What seems to work for me now w/o too much headache is to disconnect one battery and trickle charge it leaving the other battery connected. Then if she sits for more then a week I'm swap the batteries and charger. I always thought I could leave the batteries as normal and hook up a product like a Battery Tender but it seems the electrical system doesn't like that. Any thoughts?

 

[BK]

Very interested in this thread as I've been trying to figure this drain for a few years and my hearing isn't nearly good enough to hear any relays to help me track this problem. I've tried also to routinely hook up trickle chargers to the batteries and that seems to get the batteries up to proper charge but screws up something either in the PCM or elsewhere that causes the torque converter to lock/unlock. Then the only way to fix it is to disconnect the batteries for a period of time, reconnect them and set the ECM (cycle to gas pedal routine three times). What seems to work for me now w/o too much headache is to disconnect one battery and trickle charge it leaving the other battery connected. Then if she sits for more then a week I'm swap the batteries and charger. I always thought I could leave the batteries as normal and hook up a product like a Battery Tender but it seems the electrical system doesn't like that. Any thoughts?

Interesting...
I use one of the 1.5 battery tenders, along with a Sears smart charger for the bulk of the charging.

I used the Sears first, once all charged, I leave it over night with the 1.5a battery tender.
IT hasn't effected my 99 like it effects your 98.5.

My Battery Tender has very low output ripple.
I've never checked the Sears smart charger.
I would suspect the ripple of the battery charger.
Have you tried another one?

Also, I've noticed that the electronics in the truck get sort of upset, and act a little hanky when the batteries are getting tired (the internal resistance is getting high = bad battery), seems they rely on the battery to act as a larger filter.

 

[rotohead]

Interesting...
I use one of the 1.5 battery tenders, along with a Sears smart charger for the bulk of the charging.

I used the Sears first, once all charged, I leave it over night with the 1.5a battery tender.
IT hasn't effected my 99 like it effects your 98.5.

My Battery Tender has very low output ripple.
I've never checked the Sears smart charger.
I would suspect the ripple of the battery charger.
Have you tried another one?

Also, I've noticed that the electronics in the truck get sort of upset, and act a little hanky when the batteries are getting tired (the internal resistance is getting high = bad battery), seems they rely on the battery to act as a larger filter.

I've used the small Battery Tender, a KeyLine trickle charger (Consumer Reports highest rated) and a Black and Decker trickle. The KeyLine output is .75 and seems to act the best with the truck system. Where I have problems is hooking these chargers up to the batteries with them still connected to the truck. If I disconnect the batteries, put them on the chargers then when I want to use the truck hook them back up, set the ECM then the truck runs fine and shifts properly. Of course I have to reset all my presets on the radio which is kind of a PITA. If I don't disconnect the batteries the chargers seem to disrupt the truck computer such that it has all sorts of shift problems, everything from not upshifting out of second, sometimes TC lock/unlock constantly and oddly downshifting or lock/unlock when I turn the headlights on. All very annoying. I thought hooking chargers up to a vehicle directly w/o disconnecting batteries wouldn't harm anything. Am I wrong? I've got new MAX27 Walmart batteries. Lately if I don't plan to drive the truck for the next week I will disconnect the pass side battery, put a charger on it until it fully charges, then hook that battery up and switch to the drivers side battery (unhooked). That saves me from doing the preset on the radio and doesn't seem to bother the computer. Probably what I'll have to do from now on.

 

[BK]

you are suppose to be able to hook up a charger with the battery connected, yes.

All of the trickle chargers / maintainers are just that, once a battery is fully charged, you use one of them to keep the battery happy, and deal with any parasitic drains.

The alternator is actually a terrible battery charger, the high ripple current in the battery from the alternator is terrible for the charge of a battery.

You should use a good programmable charger, capable of about 40amps or so, and let it do a first charge on the set of batteries.

Than once that has gone through it's cycle, use a maintainer.

I've had odd ball problem with my shifting too, and the bad batteries AND shielding / tywraping the ground wire to the top/inside of the alternator bracket.
If the batteries become problematic, the ground wire treatment greatly reduces the unlock / lock problem to near nill. With good batteries and the ground wire treatment, it just doesn't happen.

You may want to check the quality of your grounds and ground wires as well.

 

[rotohead]

I've got my drain down to .232amps after re-doing some wiring and other changes. Do you think that is about the normal current draw?

 

[BK]

When I fixed a few things and unplugged my aftermarket alarm, I was down to about/less than .02amps.
So long as you have your decimal in the right place, I think you still too high.

Leave the truck locked up, and the amp meter on the battery, come back in an hour, and if your still 10x more than mine, I think you may still have something else going on.

From all I could find, it's expected to be less than .07a , commonly, for "modern vehicles" (lots of computers on board that are suppose to go to sleep).


If your still at .232amps after sitting an hour, than you'll have to start pulling fuses to find out how much current is going to what branch.

For my 99, I had to jam the door switch closed, so I could keep the door open, want till everything went to sleep (about 30 minutes for my 99), and start pulling the fuses on the drivers side of the dashboard.

For me that seatbelt timing module was "stuck on", and leaving it unplugged for a while seemed to have reset it, so far soo good for me.

 

[rotohead]

Yeah, I kind of think .232 is high too. That's just with one battery hooked up. If I connect both batteries it drops to .117 and yes, I leave the meter hooked up and come back after a hour and get a reading. When I first started troubleshooting I was at .756amps and found a auto-lock device for my exhaust brake was part of the key-off draw. That brought it down to the current .232 but didn't check much else. I'll keep looking and see if I can find something else.

 

[BK]

Well if you hook up the 2nd battery, but only have 1 meter on the one battery, it's just that the other 1/2 of the current is being sourced by the 2nd battery, the current the truck wants really isn't dropping.

Do you have the same seat belt timing module I do under the center seat?

 

[rotohead]

That's what I figured having both batteries but reading off just one. And yes, I have the same seat belt module under the center seat. It's one my list of things to check as I had problems with it in the past. I have suspicions about my transmission (valve body) and my after market stereo system. So your current reading is .07?

 

[BK]

my current reading is less than .02a, after sitting.

I assume your small fuse panel is where mine is, on the drivers side of the dash.
so jam the door open, jam the door switch in, let it sit, than start pulling one fuse at a time and see which one drops how much current.
That's what lead me to the seat belt module being stuck, and well hearing the solenoids in the seat back click when I pulled the fuse really was my major clue.

I don't remember where the fuse is that feeds the transmission, maybe under the hood... same thing... pull one fuse and one relay at a time....

(sorry if you've done that work already or are familiar with the process)

Than I pulled out the connectors from the seat harness to the modules and saw the current drop and heard the solendoids again, so dug out the module, unplugged it for over night.

knock on wood, ok still.. but hear that there is a common problem with them going bade.

It was about .21amps per seat.

 

[rotohead]

Did some more research and found for most models of Cummins Dodge trucks the key off draw should fall somewhere between .005-.035 amps depending on accessories.

 

[BK]

Did some more research and found for most models of Cummins Dodge trucks the key off draw should fall somewhere between .005-.035 amps depending on accessories.

Make senses.

When I was researching it, I couldn't find anything like that that was dodge/CTD specific, just a few sources that seemed to agree that "modern vehicles" should be less than .07a.

I've now gone a couple of times with the truck sitting for a week (7 days) un-touched , and it's fine when I go to start it up.

 

[HHhuntitall]

My 98.5 did the same thing after I had it a few years. After surfing the TDR, I found an article about the seatbelt module, and after beating on it with a small ball-pien, it hasn't drained a battery in several years..... Crude? Yes. Effective? Yes. Much like myself....

 

[Berrigan]

My 98.5 did the same thing after I had it a few years. After surfing the TDR, I found an article about the seatbelt module, and after beating on it with a small ball-pien, it hasn't drained a battery in several years..... Crude? Yes. Effective? Yes. Much like myself....

The seat belt modules are designed to use 12v power for 30 minutes after engine shutdown and driver exit of the truck. After 30 min they should stop using power.An easy way to test it is to get out of the truck and close the door with the window open. Pull on the seat belt where it enters the retractor hole (about where your left shoulder is when sitting in the seat). the seat belt should pull out and retract when released. After 30 minutes you should find that the seat belt won't pull out. That means the module has stopped using power. as soon as (can't remember) either the door is opened or ignition switch is cycles the belt will be free again.

It uses power to let the belt slide, but in the event of a crash and the batteries are damaged and no power available the seat belt locks to stop your body from going forward into the dash. I fails safe on loss of power. It also is a parasitic drain for 30 minutes.