Frenchie Posted November 6, 2012 Share Posted November 6, 2012 The battery on my 2012 FX4 keeps dying. Dealer has put in 3 new batteries so far and the last one died after sitting for 2 days. Mechanic says this is normal and that I should drive it every day. The truck does have a rust control module installed on it. Does anybody else have similar issues. Quote Link to comment Share on other sites More sharing options...
YT90SC Posted November 7, 2012 Share Posted November 7, 2012 What the hell is a rust control module? Unhook it and see how long your battery lasts. Key off parasitic draw should be less than .05 amps once all the modules sleep. IF its over that, its too much, period. Stock parasitic draw should last at least a month even with the smaller option battery. Quote Link to comment Share on other sites More sharing options...
akirby Posted November 7, 2012 Share Posted November 7, 2012 What the hell is a rust control module? It generates a mild electric current throughout the chassis. They're used a lot on salt water boats. That would be a likely culprit. Quote Link to comment Share on other sites More sharing options...
theoldwizard Posted November 7, 2012 Share Posted November 7, 2012 What the hell is a rust control module? Unhook it and see how long your battery lasts. Key off parasitic draw should be less than .05 amps once all the modules sleep. IF its over that, its too much, period. Stock parasitic draw should last at least a month even with the smaller option battery. I agree with the exception that some of those modules might wake up occasionally and do something. During this brief period, you might see current draw as high as 0.500A. This should very infrequent and only last for a second or 2. Quote Link to comment Share on other sites More sharing options...
Frenchie Posted November 8, 2012 Author Share Posted November 8, 2012 It's currently at the dealer, has been since Monday night, has anyone else had a similar problem. I had disconnected the rust control module for a week and didn't have a problem but then again I was using the truck almost daily. I reconnected the module on the Friday and by Monday afternoon battery was dead after the truck sitting all weekend, so could be the module. Mechanic's answer was "you don't drive it enough" and "put a trickle charger on it when parked". Has anyone else on the forum ever run into this problem or do you know of someone who has. Quote Link to comment Share on other sites More sharing options...
akirby Posted November 8, 2012 Share Posted November 8, 2012 Should have left it disconnected while it was sitting for a couple of days. That's the only real way to test it. Quote Link to comment Share on other sites More sharing options...
betaiota Posted November 12, 2012 Share Posted November 12, 2012 I used to install those rust modules a looong time ago. That's your culprit, no doubt. Quote Link to comment Share on other sites More sharing options...
Frenchie Posted November 13, 2012 Author Share Posted November 13, 2012 You are right betaiota, pickup her up yesterday from the dealer and they say that was the problem. Apparently it was drawing 0.8 amps, they replaced it with a new one and kept it over the weekend and checked the battery status on Monday and all was good. Quote Link to comment Share on other sites More sharing options...
gzukoff Posted February 22, 2019 Share Posted February 22, 2019 So reviving a dead thread .. The "park switch" may be the cause of the parasitic draw on some of the console equipped models, it's an inexpensive switch that sends a shutdown signal to the BCM. When it goes bad the dash lights do not shut off and it drains the battery. Fords fix is to replace the whole shifter assembly at around $650.00, they do not sell just the switch. Here is the replacement switch with an more detailed explanation of why it happens. https://www.ebay.com/itm/292931561061 Quote Link to comment Share on other sites More sharing options...
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