smart car towing question

[tony6373]

I have a Blue Ox alpha tow bar and base plate installed on my 2012 smart. And have a Blue Ox patriot brake system on order. The smart owners manual says to have the dealer install a battery disconnect switch. The dealer doesn't seem to know about this switch and has not returned my call. The positive battery terminal has a forest of wires going to it. Which wire(s) do I need to disconnect (with a switch) while towing? The place that installed the base plate said I didn't need to disconnect anything. I need to leave for Florida the end of the month so time is growing short.

Thanks for your sharing your knowledge,

[Phoenix]

This is not the best long-term solution, but it's quick and cheap:

Everstart 936W Positive and Negative Terminal Disconnect for 12-or-24-Vehicle Dynamic Control Systems: Automotive : Walmart.com

Note: Also available at Harbor Freight, AutoZone, Pep Boys, O'Reilly's, etc.

This can be installed on the negative terminal of your battery, which probably has fewer (perhaps only one) connection(s) to ground.

There are lot better solutions, depending on your specific needs; but most are electrically similar to this.

If you shop around, there are some locking switches designed for automotive use; but for the most reliable, permanent mod, check out marine battery isolator switches.

[Protagonist]

My toad isn't a Smart— it's a Honda— so I'm speculating here. Take my comments for what they're worth.

When you tow, many toads require you to leave the key in the ignition, in the accessory position, so that the steering wheel doesn't lock. But with the key in the accessory position, anything that draws power will continue to draw power with no current from the alternator to keep the battery charged. The switch is intended to prevent that. I'm surprised that Smart recommends a kill switch instead of just pulling a fuse from the biggest current users. My Honda owner's manual suggests pulling the radio fuse and that's it. But if that's what the manual says, best to do it that way to avoid voiding the warranty.

The best thing to do would be to disconnect ALL of the wires at once by means of the switch. Easiest way is to put the switch directly on the red post, and have all of the red wires connect to the switch.

Battery disconnect switches are required safety equipment in all NASCAR and most other racing cars, so there's no shortage of makes and models to choose from. If your battery is readily accessible under the hood, then a switch that mounts directly to the battery terminal is best.

Amazon has a few to choose from, for both top-post and side-post batteries. Prices vary by brand, with cheap being about six bucks, and moderate being about ten to fifteen. This one is typical:Amazon.com: Top Post Battery Master Disconnect Switch: Automotive
You can probably avoid the low-voltage-relay types that go for $75 or more unless you want to mount the switch on the dashboard to control the disconnect under the hood.

[Coloradobus]

Tony,
Checked the FMCA dinghy guide for 2012 Smarts and there was an asterick description of your switch. So don't know, other than install one of those battery disconnect twist knobs on the battery the negative terminal. You might check with www;irv2.com forum. I remember reading other tricks towing Smarts., one being to bungie the steer wheel forming and "X" attaching to seat base rails, to keep steering wheel from going into a wobble while towing.

[tony6373]

I guess I should have said that the battery is located under the passenger side carpet and not easy to get to. There is not very much room in the battery well but maybe a small switch would fit? I need the power for the brake system. Also not sure if completely disconnecting the battery would erase the memory of the ECM and TCM. I was hoping that someone who is actually towing a smart might respond with what has worked for them?

Thanks for your input,

[Protagonist]

Originally Posted by tony6373

I was hoping that someone who is actually towing a smart might respond with what has worked for them?

You may have better luck asking that question on a Smart forum rather than an Airstream forum.

When I was setting up my Honda as a toad, I got most of the information I needed from the Fit Freak Forum, a site dedicated to Honda Fits.

But with the battery in an awkward location, you'll want a disconnect relay and a dash-mounted switch. The one I've linked to includes a wireless remote to go on your keychain, which is a nice feature, but not essential.
Remote Battery Disconnect (1 Button) : Amazon.com : Automotive

[ROBERTSUNRUS]

Hi, "Smartstream" tows a smart with his Classic Motorhome. See if you can contact him.

[Smartstream]

Hi Tony, I do tow my smart but mine is a 450 European model and the key switch and shifter are different than those on the U.S. 451 model.

Below is the procedure for the U.S. model smart. When you put the trans in neutral make sure the "N" shows on the dash panel and when you turn the key to the left make sure the dash panel goes off. Some say to carry an extra key in case the auto door lock sets but if the dash is off the auto locks are not supposed to set.

The important thing is make sure the car is in neutral and the dash is off.



PROCEDURES TO READY SMART CAR FOR TOWING

(1) Position car straight behind the motorhome within reasonable reach of the hitch.

(2) Apply foot brake, set car hand brake, shift into Park, turn ignition off.

(3) Attach hitch and all appropriate attachments.

(4) Inside the car, put key in position 2 without starting.

(5) Apply foot brake and hold down while you shift into Neutral, turn key off (to the left) as far as possible (in position 1 key won't come out), release foot brake, release hand brake.


PROCEDURES TO READY SMART CAR FOR UNHITCHING


(1) Set car hand brake.

(2) Turn key to position 2 without starting the car.

(3) Apply foot brake and hold down while you shift into Park, release foot brake.

(4) Unhitch the car.



On my smart I hook up on flat ground and pull up a foot or so short. After putting the car in neutral and turning off the key, I pull the car ahead by hand to attach the tow bar. It's very easy to roll and there is no doubt it is in neutral.

Also if you have a motorhome with a long rear overhang sometime you can have a problem with front wheel oscillation especially on sharp turns coming in and out of driveways. This is easily solved by putting a binge cord around the bottom of the steering wheel and the seat frame to stabilize the wheel. I have never had to do this but I do take driveways very slowly.

[tony6373]

I have been spending some time on the smart car forum. There seems to be a lot of confusion about what works and what is just hype. But I did buy a 100 amp disconnect today just because the factory says I need it. The Blue Ox Patriot brake system has been shipped and should be here next week. Meanwhile the 270 is at a local shop having the brake pads replaced. Should get it back on Monday. Lots to get done before leaving for Florida the end of the month.

[Smartstream]

Like many things on forums there is a lot of over thinking. Towing the smart is really quite simple, make sure it's in neutral and turn the key off and don't worry about it. I've seen more than a few cars with oscillating front wheels and it's not a big deal. Just understand what causes it and take it easy. Then go camping and have fun.

[DaveFL]

Does your MH have a rear camera, on mine I can't see the Fit without the camera(except on turns), nice to know it is still attached. If you do you might have to adjust where it shoots, mine was set too high and gave a good picture of the horizon where I wanted a lower view.

[Protagonist]

Originally Posted by DaveFL

Does your MH have a rear camera, on mine I can't see the Fit without the camera(except on turns), nice to know it is still attached. If you do you might have to adjust where it shoots, mine was set too high and gave a good picture of the horizon where I wanted a lower view.

In my Interstate, I can see the outside mirrors of my Fit all the time in my Interstate's outside mirrors. Barely. But I'm sure glad to have the rearview camera!

I also bought a couple of yellow Velcro cable ties, and fasten them top dead center on the Fit's steering wheel. Which gives me a point of visual reference when I check the camera, to see if the Fit's wheels are tracking properly in a turn, as the steering wheel turns to follow the front wheels. So far they have tracked just as they're supposed to, but it's good to be able to see for myself.

[pgr32e]

During our little westward adventure in 2010, came across an Airstream moho towing a smart car on a tandem trailer. A more expensive option, but a whole lot less fuss and wear on the car......Phil

[tony6373]

Yes, I have installed a Garmin wireless camera inside the back window so that I can adjust it without a ladder. So far I have been powering it with a 14.4 Volt wireless-drill battery. I'll wire it in permanently later. I like the idea of a tell-tail on top of the steering wheel.