C Max Question

[Daveyboy555]

I recently purchased a 2013 Ford C Max to flat tow behind my Thor Ace. I was trying to determine whether the mileage will go on to the vehicle when it is flat towed (which I'm guessing it will) or maybe if the vehicle is not running it won't add miles to the odometer when it is being towed.

[DouglasC]

Will - - You have figured it out - that the key does not go all the way back to the "OFF" position - - but it is not in the "ACC" position either - - so there is no drain on the battery.

As far as using the Brake Buddy - - the brakes on my 2012 Fusion hybrid work differently than the ones on the 2008 Mariner did. The brakes on the Mariner were always "powered" and so it was necessary to set the pressure very low (about 15#) for it to work properly. On the Fusion, when the key is back as far as it will go towards "OFF",and the tranmission is in Neutral, the brakes are not powered and I set the pressure on the Brake Buddy as I normally would (about 70#).

If the Brake Buddy is set properly and one drives in a normal manner, the Brake Buddy never engages (it's only set to engage in a near panic stop situation), therefore there is no drain on the battery.

If you feel more comfortable using a charge line, then by all means do it. I'm just telling you that I've towed these 2 hybrids over 30,000 miles and never had a "dead" battery problem. "To each his own."

Doug

[willald]

DouglasC - After reading some of your previous posts talking about the Ford Fusion and the key position, I think I see where our 'disconnect' here is:

I thought you were turning key all the way to OFF position, which is impossible when tranny is in neutral. Thats not the case, though - You turn it as far as it will go, which is really not the OFF position, but just before it. Sort of between ACC and OFF.

I've thought about doing that, but have not, 'cause as I said before, we just don't know if Ford has other reasons why they recommend leaving it in ACC position that we don't know about.

One thing I do know for a fact: Whether its in OFF or ACC position, with the Fusion hybrid, power (active) braking stays on all the time. Sit in your Fusion with ignition off, and hit the brake pedal a few times. After a few times, you'll hear a motor kick on, for the active braking. That is going to draw down the battery, eventually, as your supplemental braking system engages the brakes. And, thats in addition to any power the brake system (brake buddy in your case) uses from the battery.

For that reason, even if I set the ignition switch like you do....I'd still want a charge line. Starting batteries are not meant to be drawn down like that. While you may not draw it down enough to notice any issues yet...You will shorten the battery's life, and get to replace it sooner. A charge line is MUCH cheaper than an untimely new battery for your Fusion. 🙂

Will

[willald]

DouglasC wrote:
I have towed hybrids for over 5 years now (4 years with a Mercury Mariner and 1 year with a Ford Fusion). I have always turned the key all the way back towards the OFF position, not ACC. Have never had a problem with battery drain - - or any other kind of problem either. Why would u need to put the ignition in ACC position??

Well, two reasons:

1. Owner's manual says to do it that way.

2. When tranny is in neutral (which it obviously has to be when towing), you cannot get the key to OFF position like you are implying. Its either ON, or ACC position. Since Ford recommends using ACC position, thats what I use.

How are you getting the key to OFF position, with the tranny in neutral? Have you disabled the inhibitor switch in the shift lever? It wasn't too hard to do that on Fusion models prior to 2013, but on the 2013 models, it is way more hassle than its worth (I already tried, hehe).

I have a Brake Buddy and plug it into the 12V outlet which is always "live" even when the key in not in ACC position.

On long straight trips from point A to B I have left the toad set up that way for as long as 3 days while using pull-thru sites in campgrounds (or overnighting at Wal-Mart) and never had a problem with the battery running down.

Well, if you've found a way to keep key in OFF position when towing, battery drain would not be much of an issue.

However, I'd be a little hesitant to do that, since it'd be going against the way Ford recommends you do it. There may well be other reasons Ford wants you to keep it in ACC position that we don't know about, that may bite you later.

I'll stick with putting it in ACC position. 🙂

Will

[DouglasC]

I have towed hybrids for over 5 years now (4 years with a Mercury Mariner and 1 year with a Ford Fusion). I have always turned the key all the way back towards the OFF position, not ACC. Have never had a problem with battery drain - - or any other kind of problem either. Why would u need to put the ignition in ACC position?? I have a Brake Buddy and plug it into the 12V outlet which is always "live" even when the key in not in ACC position.

On long straight trips from point A to B I have left the toad set up that way for as long as 3 days while using pull-thru sites in campgrounds (or overnighting at Wal-Mart) and never had a problem with the battery running down.

[willald]

We tow a Ford Fusion Hybrid, with has the same engine, drivetrain as the C max hybrid.

No, miles will not log on the odometer, nothing to worry about there.

One thing you do need to do ASAP, to save yourself a lot of headaches and difficulties later on: Install a charge line from your MH to the C max, to keep the battery charged up. Pretty easy to do, and will prevent you from running down the car's battery.

I actually put an ammeter on the battery to test it out. Found that even with EVERYTHING turned off, ignition in ACC position and tranny in neutral as it has to be when towing...Electrical system was still drawing around 3 amps from the battery all the time. If you have a supplemental braking system, in addition to any power it needs, the active braking system of your hybrid will also kick on every now and then, using up even more battery power.

We found after just 4 hours of towing, battery was weak enough it would not operate the power locks. Only took ONE trip of that happening, before I installed a charge line. 🙂

You NEED a charge line with these Ford hybrids, period. Good thing is, once you install it, you'll can pretty much forget about it, and never worry about battery charge again.

[tjholyoke]

We also have a CMax to tow behind our ACE! First attempt at it will be Memorial Day weekend. Will bring the jumper cables just in case...

[afrescopXx]

We are towing our C Max four down. With the ignition turned to the factory required "ACC" position, no mileage accumulates. It tows like a dream, don't even know it is back there.

The one problem we incurred was that the 12V battery ran down after 4+ hours of towing. After having it checked out it was discovered the 12V connection from RV to C Max had not been connected to the battery circuit. We have a Blue Ox Patriot brake box that requires 12V for operation. I will not know whether or not the battery stays charged until our next long tow (4+ hours) in a few months.