New to the forum. I did a search relative to the Urea heaters and could not find my answer.
I picked up a leftover 550 from a dealer in Vt that had been sitting, was made late last August.
If the truck sits for more than a few days the batteries are flat dead. I charge them up and it will last for a few days then they go dead. I brought it to the dealer, they tested the batteries and said they were fine. They also checked for a draw and it showed 29 milli amps which was within spec. They swapped the batteries from another truck, I still have the problem. The test was preformed in a warm shop.
No lights are on , snowplow is off the truck.
My question is, do the Urea heaters kick on if the key is in the off position? There are 3 heaters that are controlled by a 25 amp fuse in the under hood power box. I pulled the fuse and let the truck cold soak for three days and the truck started fine. I put the fuse back in and the truck did not start due to dead batteries after 24 hours. We have not dropped below 15 above at my place in NH since I got the truck. The heaters may be kicking in above what the set point is. It has been down in the 20's however.

Any other ideas on what could be drawing the batteries down while parked and the key off would be appreciated. The dealer says I should just drive the truck every day, there solution.

 

There should be no heaters kicking on when the key is off. sounds like a problem to me. Their solution is no solution. Sounds like time to call BS, or find another dealer.

 

Welcome to FTE. I don't know how a Ford dealership can call a parasitic draw normal. Their proposed solution is unacceptable and not a solution. It sounds more like ignorance. Find another dealer and tell them what you found as far as pulling the fuses of the heaters for the urea tank.

 

Dealer is blowing you off for sure. Battery draws can really test one's patience diagnosing, and they don't want to put the effort in. Don't be too surprised if it takes a motivated dealer a few days to a week to track it down being intermittent in nature. Far as the draw goes, 29 milli amps is quite normal these days. Some off the German junk I work on acceptable amp draws go as high as 60ma key off. FYI my truck has sat up to two weeks without issue whenI get stuck with the service truck.

 

Dealer had said 50 milliamps' was the max allowed. I dropped the truck back at the same dealer this afternoon and I will let you know what they find out.

 

Welcome aboard Big Bob.

Hope they find your gremlin. Electrical leaks are hard to find.

 

Welcome Bob hope all turns out well in the end.

Phuzzy

 

Dealer hooked up the data recorder to see if they can catch any draws overnight. I still think that since the batteries won't hold a charge after 3 days that they are junk even thought the Rotunda computerized battery tester said they are fine and they can't replace them under warranty.

 

My 11 350 did this. They warrantied the batteries twice. Never did fix the problem. They would be dead in about 48 hrs. Had to jump it at the airport. Finally traded for a 13. Not what u wanted to hear.

 

Not sure what you have available for test equipment, but if this were happening to me I would hook up a data logging multimeter and a Hall effect DC non-contact clamp-on current probe around the terminal block on the primary battery on the passenger side and leave it for a day, load up the data then trend graph it and see if there are any spikes in current draw. This is a dual battery but permanently paralleled setup. That would tell you if it's seeing higher load at certain times and whether or not you have a pattern (maybe temperature related?) or if it's completely random.

Obviously 29mA draining the battery string doesn't make sense... even a tiny 20Ah/20hr would last at least a week with that load, even taking into account its own self-discharge. It probably isn't happening at the very moment that it's being tested hence the need to monitor it for a longer period of time now.

 

Picked the truck up on Friday. Just got back from a few days of skiing so I did not have time to post. The passenger side battery tested bad so the replaced it under warranty. Only time will tell if this fixes the problem. They had the truck on their computer for a few days and never did see any draws that would kill the batteries. Thanks for the info and I will let you know in a few days if the truck starts. They did confirm that the urea heaters do not come on when the key is off.

 

Mine did this exact thing. Frustrating.

 

And what explanation they give you as why the 1st time you had it there the batts checked good,and all of a sudden now one is bad. and its never a good idea to replace just one battery.

 

The batteries that came with the truck tested fine. Second time in they swapped the batteries from a new truck on the lot, but did not test them. They also went dead. Ford would not reimburse since the computer said the batteries were fine. Third trip they did another draw test and did test these batteries, that's when they found the bad one and replaced it with a new one. Used the truck the last few days without issue, eye in the one battery has now turned black from red. Agree both batteries should be changed at the same time, but the other battery is essentially new.

 

Thats not good. The Black eye. It should be red. I see another visit to the dealer.