Community Forums

Bamadug · 07-02-2014, 11:04 AM

I tow my 2014 Ford Focus 4-down behind a Four Winds Hurricane. I have a Road-Master "Add-A-Brake" (AAB) that I've tried to connect to my MH through the 4 wire connection from MH to AAB. Once the neg wire is disconnected from the car battery, there is no power to the AAB. When you disconnect the negative wire from the battery in the car, there is no grounding possible in the car period. Then I bought a 12V DC Battery Pack/Starter that I used to power my AAB. But still, when I disconnect the neg wire from the Focus battery, the braking signal from the MH doesn't come through to activate the AAB. I've been towing the Focus without a braking system, which, is not only illegal in most states, but I don't like taxing the MH brakes and transmission. I'm leery to disconnect the positive wire since Ford does not recommend this. Have you checked to make sure you car braking system is working when you brake the MH? If so, have you had any Focus tranny problems?

sbranen · 07-02-2014, 06:53 PM

So far I am very happy with our towing setup. It worked flawlessly on our trip last week to the Yosemite area. The brakes on the tow vehicle worked just as they should. It takes just a few minutes to get the car ready for towing using the switch that was installed to cut off and turn on power to the vehicle chassis. US Gear recommend cutting off the positive cable and not the negative one. This allows you to use your battery for braking and other power needs while isolating your transmission from the battery.

hdmoxness · 07-03-2014, 09:09 AM

The Focus 6-speed automatic trans is great for towing because it goes into a true Neutral.There’s no idling, no time limits, no hydraulics or driveline disconnects.Tow up to 70 mph all day long.

Here are some important points:
1. The parking lights and turn signals in the towed Focus should be wired and lighted independent of the car’s wiring and bulbs.
2. The towing brake system installed in the Focus inevitably needs power and ground from the car battery.
3. When hitched up, the MH and the Focus are going to be grounded together.
4. Because of this, disconnecting the negative cable (and its two little wires) from the battery becomes useless.When you hook up your brake system + and - to the battery, the Focus electrical system (including transmission control) just gets its ground back through the relatively tiny wires in your brake system hook up.
5. Electrical isolation of the transmission then can only be achieved by disconnecting the positive battery cable (with its little wires) from the car battery.If this is done through a proper battery switch, the positive disconnect is a safe and easy operation.Now your towing brake system can easily get power from the car battery.

We’ve towed our 2014 Focus the better part of 4,000 miles since January 2014.Besides connecting the Blue Ox towbar, safety cables, the 4-wire electrical cord, and the breakaway switch, the only other things I have to do is flip the SMI Stay-IN-Play Duo brakes system toggle switch to ON and rotate the Battery Doctor battery switch 90° to OFF.

phx2400 · 07-07-2014, 09:24 AM

Hi, we found this topic very helpful, since we have a 2014 Focus Titanium, bought because of its being flat-towable. We have the Blue Ox Aladdin tow bar, BO base plate, and independent taillight wires. We thought we were all set, planning to put a Battery Disconnect into the negative cable path as described by hdmoxness, then install a power supply socket for running the brake buddy that the RV shop sold us along with the Blue Ox tow setup.

Can hdmoxness (or anyone) tell us how the Focus will ground to the MH? Is that through the tow bar or the wiring harness? Also, if the brake system power wiring is isolated by connecting directly to the Focus battery, how can the transmission control modules get ground that way?
Is there a way to test the Focus to see if it is being grounded, or if we have eliminated the ground?

Thanks.
Rob

hdmoxness · 07-07-2014, 09:56 AM

Unless your towbar is made of plastic, I think the two vehicle frames, MH and toad, are tied (grounded) together.

When I was wrapping up my SMI brake installation, I found that the Focus' electrical system was still live after I used the battery switch I had installed on the negative side to disconnect it. A quick search found that the truck accessory and hitch shop which installed the independent tail lights had grounded the "independent" tail lights to the Focus frame under the rear bumper. Well, I remedied that situation, but was puzzled to find the car's electrical system still alive when hooked up for tow. Then it hit me (head slap, lol) that because the SMI braking requires MH brake light actuation as well as a signal from the controller's accelerometer, the brake system ground was tied to the MH ground, and the MH ground was tied to the Focus frame through the tow bar, providing ground to the car systems.

So my problem was solved when I moved the battery switch to the positive side of the Focus battery. That ensures that the car and trans can't get any power. However, this may be specific to the SMI brake system, which requires two inputs before it will apply the brakes: MH brake lights on and a deceleration signal from its own controller.

This is all a tricky issue and I hope I haven't confused or misled anyone. A good wiring diagram and understanding of the toad brake system is necessary. I hope this helps; I'm still open to inquiries.

phx2400 · 07-07-2014, 10:17 AM

So it sounds like we need the positive disconnect solution, even though the brake buddy doesn't use those wiring inputs. Do your Focus presets survive the positive disconnect? I thought I saw you have the Titanium with PB start like we have. I'm hoping we will not have to do a bunch of resetting every time we disconnect/reconnect.

hdmoxness · 07-07-2014, 06:43 PM

Yes, we have a Titanium with Sync and PB start. The only thing we seem to lose is the volume attenuation setting in audio options. Radio and Sirius presets, clock, and other stuff seem to stay put. So when we arrive after towing, we do two things: (1) set the volume attenuation to "7;" and (2) delete our old "MyHome" and add our new home location so we can find our way back to our new campsite!

phx2400 · 07-08-2014, 06:57 AM

Thanks for the good news. I presume you are still using the battery doctor disconnect, just on the positive side, and it has no problem handling the positive power. At first, I was wishing I knew to order 2 disconnect switches and do both negative and positive, but that's probably overkill. Anyway, I should have the switch and wiring cable to connect RV to car in a couple more days, so I should be able to try this all out by the weekend.
Thanks.
Rob

raoulwv · 07-08-2014, 07:28 AM

FYI, I have a Focus and use a Brake Buddy also. I have the BB wired directly to the battery and the disconnect on the negative battery cable. The Focus electrical system does not stay "live" in my case. It seems you can put the disconnect on either cable. I prefer the negative simply because that's what Ford recommends and I'm still under warranty.

hdmoxness · 07-08-2014, 11:49 AM

Rob - Yes, the BD rotary battery switch handles all the juice, including the starter without problem. I forget the rating, but it's plenty. Yes, disconnecting both sides would be overkill. See the Brake Buddy question below and good luck with your install.

Rod - I'm glad your setup is working correctly. Help me (and other readers) with some info. What actuates the Brake Buddy? I'm guessing it applies the toad brakes whenever the accelerometer built into the Brake Buddy box senses the MH slowing down. Is that right?

The reason I ask is that the way the brake system is wired is crucial to this grounding issue. If the brake system has no electrical connection to the MH at all, a negative disconnect is probably perfectly acceptable. (Rob, if your Brake Buddy doesn't touch the MH wiring, you may be good for the negative disconnect.) My need for positive disconnect was determined by my brake system, the SMI Stay-IN-Play Duo (SMI also makes the Air Force One brake system for DPs with air brakes). I chose it for it's one switch design and its permanent installation, since we don't switch tow cars and plan to use this new car for a long time. Our Focus is in tow about once a week, so I don't want to have to "install" and uninstall the brake system again and again. One feature of the SMI Stay-IN-Play system is that in addition to its own deceleration signal, it needs to see that you have actually applied the MH brakes. This prevents any accidental or unwanted braking action when you don't actually put your foot on the MH brake pedal (except for the breakaway scenario). To know if the MH brakes are on, the SMI system is connected to the MH brake lights, and since the SMI wiring is also connected to the Focus battery, that is how ground gets back to the car's electrical systems, despite disconnecting the negative cable terminal from the car battery.

Is the SMI system the only one that connects to the MH electrical system via the MH brakes lights or otherwise? I don't know. Anybody?

raoulwv · 07-09-2014, 07:45 AM

Quote:

Originally Posted by hdmoxness

Rod - I'm glad your setup is working correctly. Help me (and other readers) with some info. What actuates the Brake Buddy? I'm guessing it applies the toad brakes whenever the accelerometer built into the Brake Buddy box senses the MH slowing down. Is that right?

You are correct. MH and toad wiring is isolated also.

phx2400 · 07-09-2014, 09:23 AM

Our Focus has independent tail/signal/brake lights installed, that run and ground only to the MH, per the installer. The BB's only power is to a 12v outlet, the old cigar lighter outlet. I will have to add one of those, fused and wired direct to the Focus battery. BB offers one, I think, but I should be able to get that at the auto parts shop. That has to be able to handle 15 amps, per the BB instruction sheets. The BB operation sounds like what you said, it senses deceleration that is rapid enough to interpret as the MH braking, and presses the toad brake pedal via air pressure extending a rod from the device.

I had already bought the BB before I saw other systems such as the SMI, and I think one from US Gear.

Anyway, I will try the negative disconnect first and see how that goes.
Thank you both for sharing your experiences.
Rob

jamesrxx951 · 07-09-2014, 04:10 PM

Quote:

Originally Posted by hdmoxness

The Focus 6-speed automatic trans is great for towing because it goes into a true Neutral.There’s no idling, no time limits, no hydraulics or driveline disconnects.Tow up to 70 mph all day long.

.

Technically that is not accurate. When the shifter is in park, reverse, neutral, and drive sitting still, the transmission is engaged in reverse and 1st gear. This transmission has 2 separate clutchs and input shafts. So depending on what clutch is engaged will determine which way you will move. This is why it very important to follow the flat towing procedures exactly. If there is any voltage in the system present and a clutch is engaged, very very bad things happen. Destroyed transmissions, destroyed engines, and in very rare cases pistons leaving the block (1st or rev gear ratios spinning the engine at 70 MPH speeds) through the hood. So anyone flat towing don't short cut anything and you will be fine.

hdmoxness · 07-10-2014, 09:56 AM

I stand corrected. So, when the Focus shift lever is in "N," how does it compare to when you come to a stop light in a manual shift car? Is it like waiting for the green with the shift lever in 1st and your clutch pedal depressed? Or is it like waiting for the green with the shift lever in neutral and your foot off the clutch? Can you tell us more about this automatic/manual? I had gathered that it has two clutches, but I don't understand the mechanics of that. Can you add more details? Do you have Ford factory experience? Thanks for your help.