Posted November 22, 201410 yr Hey fellas Started diag on a battery drain today. Seems when I disconnect the alternator the drain goes from 480mA to under 50mA ........ how do I determine if I have a bad ground on alternator an open circuit ..... or just a bad alternator.
December 7, 201410 yr Author Just to answer that. I had the batteries tested - 1 was bad and one was good. I already knew this thats why I isolated the passenger among other things (bad). So now I have new alternator, new passenger battery and a good drivers. I will run through the pulling fuse exercise again ....... and will capture a video of part of it ........ but yeah its pretty much what I have already done.
December 7, 201410 yr I looked and you didn't really mention what was disconnected when you did the other fuse pulling. I'm saying disconnect the positive battery terminal and everything on those 2 lugs, then bridge between battery positive and one of the lugs and then start pulling fuses. If you did exactly that then ok, if you had stuff hooked up such as things on the terminals then I would be a little suspicious and do it again the way I said, that way we remove all doubt.
December 8, 201410 yr not sure if anyone has checked theirs... but what is considered 'normal'.. with stuff like the radio (clock), security, and anything else always 'hot'? edit; just remembered (from my flatbed install last week), the 12v supply to trailer. That isn't keyed, I remember seeing a fuse for it in the pdc... but that's a lot of wire (CHECK YOUR TRAILER PLUG TOO) A little mud in the socket... ya never know! Aftermarket brake controller? Edited December 8, 201410 yr by rancherman
December 8, 201410 yr Author IOD I *think* is 50MA from factory. Unsure with non factory radio and some other stuff ......... No aftermarket brake controller. Im sure when we track it down l'll feel like more of an idiot ...... but its not jumping out at me Edited December 8, 201410 yr by JOHNFAK
December 8, 201410 yr Owner Need to get pass the alternator lugs and get into the subsystems and start measuring other circuits for draw. The lugs at the alternator fuse are the master feeds entering the vehicle anyways. As I supplied in the pic in the previous post. Heck if your out here in Idaho I'd do the testing for you.
December 8, 201410 yr Hey, FMI, are the circuits (within the cab fuse panel) hot 'after' the pdc? ie; is the cab fuse panel separate from the pdc Am I correct on the fuses in the cab are for sensing/gauge/and exciter type circuits, whereas the underhood panel is for the 'work' circuits?
December 8, 201410 yr Owner Once again the is the PDC. Everything under the hood is usually exterior circuits. The fuse panel inside the cab is going to be all cab related.
December 8, 201410 yr I am missing (or am too schematic dumb) to see the path of juice to the in-dash fuses. I see where is comes from via keyed circuit.. but at the top of the page is cut off (bottom diagram). How does this tie in to the top diagram? edit... maybe this is it? 'top diagram'.... circuit at extreme top of page has 'A' labeled inside a triangle 'to fuses in diagram 2 of 3' ??? Edited December 8, 201410 yr by rancherman
December 8, 201410 yr Owner Top pic fuse 2 & 10 supply the circuit for the key switch. Fuse 1 supplies also to the Cab. There is 3 pages of power supply for this. 2002-Dodge-Cummins-Wiring.pdf
December 8, 201410 yr Author OK found it ---- plus also the reason why I missed it the 1st run. ELECTRIC POWERED SEAT FUSE (BIG SILVER FUSE). Reason I missed it was if you are monitoring it and pull the fuse ...... it still shows 0.5A on the circuit at the 140A lug after pulling fuse.......... you have to short the circuit (scratch/spark until the energy is gone) ad then it drops to 4.5mA (~0A). So before I button this ll back up .......... do I need to do any more diagnostics or any ideas on how to determine why the powered seats are drawing at key off.
December 8, 201410 yr Owner Well for now I would just unplug the electric seats. But what's funny I've happen to have a electric seat switch here for you if need be... But more than likely you have a bad power seat switch.
December 8, 201410 yr Author How quickly will 0.5A draw drain a good battery system. As I suspect that the main draw for the dead batteries was the bad battery - not this ....... but still wanted to track down. Also - how do you diagnose a bad switch for power seats.
December 8, 201410 yr This page should give you an idea. http://www.interstatebatteries.com/content/product_info/marine_f.asp Ed
December 8, 201410 yr If he doesn't need that switch, I do. Mine's smashed & I jsut put the seat in the best position with alligator clip leads. I don't "Need" it, but it would be nice. Ed
December 9, 201410 yr Owner How quickly will 0.5A draw drain a good battery system. As I suspect that the main draw for the dead batteries was the bad battery - not this ....... but still wanted to track down. Also - how do you diagnose a bad switch for power seats. Check for draw. Since you passing power into the seat motors some how draining on the batteries then the switch must be making a weak connection. You could unhook each seat motor one at a time to see which switch could be causing it. When you find the motor that is bleeding the current then when it unhooked the draw will vanish.
December 9, 201410 yr Be sure to check the wires for rubbing on the seat, there's a good possibility you could have a wire rubbed through and grounding out just enough to start pulling a load on the circuit.
December 9, 201410 yr Owner friggin electric seat! Glad ya found it man! Talk about sitting in the "Hot Seat!"
December 9, 201410 yr Good job, John! Congrats on locating it. They can be a royal PITA (like you found out)!
Hey fellas
Started diag on a battery drain today.
Seems when I disconnect the alternator the drain goes from 480mA to under 50mA ........ how do I determine if I have a bad ground on alternator an open circuit ..... or just a bad alternator.