Batteries draining down
The batteries drain down after the truck sits a couple days. Batteries are only 3 year
old Interstates. Took it to my regular shop and they said the ECM was bad and
replaced it. But the problem is still there. As long as I use it everyday it starts fine,
but leave it for a couple days and the batteries are down too far to start it
Try cleaning up all ground points. I had something similar happen to me in a Taurus I use to own. Hooked up all new ground wires and moisture sealed them after with a rubber compound. Not sure if this will be the same situation as yours but it's a starting point. Power flows to ground and then back to positive.
Thanks, I'll try that. What makes it tough to find is that It worked just fine for 4 days after they replaced the GEM module ( not the ECM), but then it started its problem again. So I took it back to the shop, but it started just fine for them after it sat there overnight. And they say they tested it and can't find a draw anywhere.
check your distributor if it is working...right after you start the engine, positive charge powers everything, now if its not distributed properly, the charge will drain the battery completely because its getting power directly...
But as long as its running the batteries are charging an everything is working properly. The batteries only drain down after it sits for awhile and then it only does it once in awhile. And its a 7.3 Powerstroke desiel.
if that is happening then my advice is dont use any electronics while you are driving... that kind of heavy duty engine will only run a few kilometers then the battery dies out...
I would start replacing ground wires to anything electronics then in the engine bay and upgrade your negative battery wire to a 1 gauge. That seems to be the area where power is discharging. You should find all the braided wires and replace them but clean all the contact points first and ensure a good ground.
Just reread your answer, it sounds like you have a moisture leak coming onto one of your electronics. If you have a cracked windshield or a leaky one, moisture could be dripping down onto one of your relays or electronics. I had a explorer with a cracked windshield go right down the middle so it wasn't really noticeable. My power windows stopped working after a while and I even changed the relays. After a very long time and much head scratching, me and my mechanic tore the dash apart and traced every single wire and finally found a set of corroded wires next to another relay box.
yeah but what happens if there is still no ground and the battry is losing it's power? happened to mo once, so i was jumped with a different battery and when i started only the headlights were on (night driving home) and no A/C or radio... my car ran barely 3-5 km then engine went dead again...
Well, electronics and battery drainage are a bitch to diagnose my friend. I've had my share of them over the years and it takes a real smart mechanic to really find and diagnose the problem. If you can find a Ford shop with some top notch mechanics, I'd go there and let them have a go at it. They may have to have your truck for a week to really find the cause of the problem though. So maybe you can arrange a loaner from them.
i agree...besides only the shop mechanics have the equipment for that kind of problem...someone with a know-how on car eletronics would be a big help too...
Thanks for all the ideas. They've had it at the shop for a couple of days now and can't find a draw anywhere and its holding a charge fine. So whatever it is its happening intermittently. which makes it even harder to find.
Well you have to think back as to when this anomaly starts occurring and the shop has to try and duplicate it. Was the truck sitting out in the rain or heavy downpour for instance before you drive it around. We're you going offloading in mud and muck or just driving urban roads. Just some ideas to think about.
Hi, Did your mechanic/ shop finally figure out what was draining the battery?
you might want to disconnect the ground cable from your battery then put your battery charger on it to bring it up to full charge then re-connect the ground cable. If your battery is reasonably good and you start / drive your vehicle reasonable distances every couple of days, it should hold. If you only use your vehicle every few days, do lots of short drives, stopping & starting, it could drain your battery. The alternator is a "battery maintainer", not a heavy duty battery charger. Hope this is useful...
Not offering a solution, just want to share what happened with my car. The driver's side window power motor stopped working so I had it replaced at the local Ford place. When I got it back, if the windows are set on a certain setting (to go all the way down or up with only a slight short touch) it will drain the battery but if I use the setting where you have to hold the button down to get the window up or down, it does not drain the battery. Have no idea whats wrong but I do know for a fact that it is that certain setting on the power windows that drain the battery. I don't use that setting so I just keep it turned off.
Mechanic found that there were some marginal cells on both batteries and said it could only be fixed by replacing both batteries. I bought a bobble tester and found 4 of the 12 marginal even though after charging both, they read 12.8 and 12.7 after charging. After 3 days, voltage was drained.
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