Need power to my TOAD from the coach

[Gordalder]

I have a Chev Spark and GM just changed the flat tow requirements; so I now need to get 12 volts to the car from the coach. Essentially my question is what is the best way to do that? I am wondering if the tow wiring has continuous 12 Volt source I can tap into?

Thanks

[ScottBrownstein]

Since this is a Georgetown forum, I assume that you have a Georgetown RV. Don't know what year or what length. However, I believe that you will find 12 volts already present on the 7 way connector on the coach. On my 2015, it is always present. Suggest at least a 20 amp circuit breaker on the TOAD side.

[Gordalder]

Thanks, yes I have a Georgetown, just over a year old; so I am still learning things about it. I should have done a Google search before posting. Now I need to check if the brake light connection system I purchased, but am not using yet, is the 7 way connection. Good advice about the inline fuse. Thanks

[ScottBrownstein]

Originally Posted by Gordalder

Thanks, yes I have a Georgetown, just over a year old; so I am still learning things about it. I should have done a Google search before posting. Now I need to check if the brake light connection system I purchased, but am not using yet, is the 7 way connection. Good advice about the inline fuse. Thanks

If you like to leave it connected, a high current diode wouldn't hurt either, but is not absolutely necessary. I think the GM has abandoned fuse removal and recommends charging, their circuitry draws a lot of power when left on and will kill most batteries after a while.

[Gordalder]

Originally Posted by ScottBrownstein

If you like to leave it connected, a high current diode wouldn't hurt either, but is not absolutely necessary. I think the GM has abandoned fuse removal and recommends charging, their circuitry draws a lot of power when left on and will kill most batteries after a while.

The latest information from GM on the 2018 Spark is to disconnect the Battery while flat towing behind an RV. When the vehicle is being towed on a curve or in a turn the electronic stability control (ESC) brake activation of one wheel may occur, resulting in an audible tire squeal.

[ScottBrownstein]

Originally Posted by Gordalder

The latest information from GM on the 2018 Spark is to disconnect the Battery while flat towing behind an RV. When the vehicle is being towed on a curve or in a turn the electronic stability control (ESC) brake activation of one wheel may occur, resulting in an audible tire squeal.

Yes, that appears to be true. If you are going to disconnect the negative battery post, why bother with a charge line since it will simply re-apply voltage to the chassis from the RV between the charge line and the 7 way negative line. Seems like it would un-do disconnecting the battery. In addition, those brakes will probably pop a 20 amp breaker.

If you disconnect the positive post (which is not what GM says) the charge line would only try to keep the disconnected battery charged.

What's up with that?

[Gordalder]

Originally Posted by ScottBrownstein

Yes, that appears to be true. If you are going to disconnect the negative battery post, why bother with a charge line since it will simply re-apply voltage to the chassis from the RV between the charge line and the 7 way negative line. Seems like it would un-do disconnecting the battery. In addition, those brakes will probably pop a 20 amp breaker.

If you disconnect the positive post (which is not what GM says) the charge line would only try to keep the disconnected battery charged.

What's up with that?

I need the power for the brake system only.

[ScottBrownstein]

Originally Posted by Gordalder

I need the power for the brake system only.

Then you are going to have to wire it directly to the brake system, using the charge line and the negative line from the coach. Put the 20 amp breaker in that circuit.

[my10539isok]

I believe I read a post in a previous thread that Ford does not supply power to the trailer connector by default. I haven't checked mine as I don't use it for the brake assist as power supplied through the connector to the toad will be lost if there is a catastrophic separation from the coach. This would render the brake assist inoperative if it relies on coach power. I realize that's rare, but still something that needs to be taken into consideration.

Good Luck. - Mark

[ScottBrownstein]

Originally Posted by my10539isok

I believe I read a post in a previous thread that Ford does not supply power to the trailer connector by default. I haven't checked mine as I don't use it for the brake assist as power supplied through the connector to the toad will be lost if there is a catastrophic separation from the coach. This would render the brake assist inoperative if it relies on coach power. I realize that's rare, but still something that needs to be taken into consideration.

Good Luck. - Mark

You are right, but it seems that Georgetown does! Disconnect switch is a very good point. If it won't work by design...why have it?

I would disconnect the POSITIVE cable, independently attach the brake controller to the positive battery post and connect the charge line through a 20 amp breaker to the post as well. Now, this may require some high current gymnastics, but it would be the correct way to do it.

Of course, diodes in all rear signal lights as well.

[Mr. October]

Originally Posted by Gordalder

The latest information from GM on the 2018 Spark is to disconnect the Battery while flat towing behind an RV. When the vehicle is being towed on a curve or in a turn the electronic stability control (ESC) brake activation of one wheel may occur, resulting in an audible tire squeal.

We tow a 2018 Spark. I hadn't seen this. Good to know! We've had that happen several times. That's new info and not in the manual. I'll have to see how our SMI Stay-And-Play is connected. I assumed the brake squeal was that the Stay-And-Play was improperly adjusted.

[Mr. October]

Originally Posted by ScottBrownstein

You are right, but it seems that Georgetown does! Disconnect switch is a very good point. If it won't work by design...why have it?

I would disconnect the POSITIVE cable, independently attach the brake controller to the positive battery post and connect the charge line through a 20 amp breaker to the post as well. Now, this may require some high current gymnastics, but it would be the correct way to do it.

Of course, diodes in all rear signal lights as well.

I'm going to have to implement something like this. One of the reasons we got our Spark is because I wanted EASY hookup. The Dealer KNEW I was buying the Spark as a TOAD and NEVER mentioned this update.

When you say charge line here, you are referencing a separate charge line from the motorhome correct? In the case of the Stay-And-Play the charging is part of the braking system. I'll have to check the wiring, but in theory assuming the brake system is attached independently to the battery, I should just be able to disconnect the battery and be good. If correct, a battery disconnect switch should make it simple.

[ScottBrownstein]

Originally Posted by Mr. October

When you say charge line here, you are referencing a separate charge line from the motorhome correct? In the case of the Stay-And-Play the charging is part of the braking system. I'll have to check the wiring, but in theory assuming the brake system is attached independently to the battery, I should just be able to disconnect the battery and be good. If correct, a battery disconnect switch should make it simple.

OK, I am not that familiar with the Spark, but the braking problem makes sense. There is a 12 volt charge line that comes from the RV in the 7 pin connector. Normally this goes to the 12 volt battery in the TOAD through a circuit breaker and optionally a diode that would prevent the TOAD battery from discharging through the connection back to the chassis battery of the RV. In my 2015 Georgetown, this line is always at 12 volts, regardless of the key being in or the ignition being turned on.

The problem in the Spark is that the on-board computer senses situations where it wants to apply braking (turns, etc)...all by itself. This needs to be defeated. GM recommends doing this by disconnecting the battery negative cable, therefore disabling everything in the TOAD, including the computer, brakes, etc. (Clocks don't like this and often sometime means that stored data is also lost in radios, bluetooth, etc.) The problem in doing this is that the charge line from the RV remains connected to the TOAD battery and the RV negative is also connected to the TOAD chassis. Therefore, everything in the TOAD is now powered by the 12 volts coming from the RV...including the computer...and the braking, just like using jumper cables!!!! That isn't an option!

If you disconnect the Spark battery from the Spark at the positive post, the internal circuits in the TOAD are no longer powered from the RV charging line and see no voltage. So far so good. Then connect the 12 volt positive line from the Stay-In-Play to the Spark battery post itself.

You could just connect the charge line from the RV to the Stay-In-Play, which in essence powers it from the RV...and only the RV...and then disconnect the negative Spark battery connection. This will work (clock setting aside), but as another poster mentioned, in a catastrophic situation if the TOAD disconnects from the RV (I know this is really a low probability situation), the 12 volts from the RV will go away and the Stay-In-Play will shut down since it is without power...and the emergency disconnect switch will do no good, as it is talking to a braking device that is no longer running!!!

Now, if it were me, I would take a look at disconnecting the positive lug, but if that were physically too difficult which it sometimes is since modern vehicles now seem to use har bus bars and not flexible cables, I would just leave the emergency disconnect in place, knowing fully that it will never work, and connect the charge line directly to the Stay-In-Play.

[PenJoe]

Originally Posted by Gordalder

Thanks, yes I have a Georgetown, just over a year old; so I am still learning things about it. I should have done a Google search before posting. Now I need to check if the brake light connection system I purchased, but am not using yet, is the 7 way connection. Good advice about the inline fuse. Thanks

We don't have a Georgetown, but the wiring should be basically the same. I wired a Sunseeker 2500TS to a 2012 Jeep Liberty. A 7-pin from the TV to a 5-pin at the toad umbilical was all that was needed. A totally independent tail/brake/turn signal set was installed. The 12 volt connection from the TV to the toad is wired to a toad battery tender. The 12 volt circuit to the toad is actuated through the TV ignition switch. When the TV is turned off, so is the power to the toad. This set up allowed us to travel 1700 miles over a four day period without having to start the Jeep. When we unhitched, the battery was fully charged. I believe you will find this same system in your Georgetown.

By what I am gathering from others in this discussion, is that you want to segregate the Spark electrical system from the Spark battery. You could still do what I did with the Jeep. In addition you would need 2 things. A battery disconnect and a 12 volt circuit to the brake system. For the latter, I at first was going to run a separate 12 volt cigarette lighter line to the vicinity of the brake system. For our set up, we didn't have to do that.

[wrapperman]

Originally Posted by Gordalder

I have a Chev Spark and GM just changed the flat tow requirements; so I now need to get 12 volts to the car from the coach. Essentially my question is what is the best way to do that? I am wondering if the tow wiring has continuous 12 Volt source I can tap into?

Thanks

Another option is to buy a seal battery and run the stay and play off of it directly and then run charging lines from the MH to the sealed battery. Be sure to keep the disconnect switch in line to the aux brake.
When I think about it you will need to put in a disconnect switch to the sealed battery and turn it off or on before starting the toad. It could be connected to the stay and play accelerometer box. I have the stay and play on my CR-V and love it.

[ScottBrownstein]

Originally Posted by wrapperman

Another option is to buy a seal battery and run the stay and play off of it directly and then run charging lines from the MH to the sealed battery. Be sure to keep the disconnect switch in line to the aux brake.
When I think about it you will need to put in a disconnect switch to the sealed battery and turn it off or on before starting the toad. It could be connected to the stay and play accelerometer box. I have the stay and play on my CR-V and love it.

He could do that...but why. The Spark battery needs to be disconnected, why not use it to power the Stay-in-Play? If he did add another battery, why would it need to be disconnected when starting the car? It is only powering the brake controller and, as such, is electrically isolated from the Toad anyway. A small, 12 volt AGM motorcycle or PWC battery would do it since it only needs to power the braking unit during a catastrophic disconnect which would last maybe one minute anyway.

[Mr. October]

Hmmmm. Lots of things to think about here all of which add complications to the towing setup. I wish I knew about this before going with the Spark. Of course these days it seems like all vehicles are complicated to tow.

[ScottBrownstein]

Originally Posted by Mr. October

Hmmmm. Lots of things to think about here all of which add complications to the towing setup. I wish I knew about this before going with the Spark. Of course these days it seems like all vehicles are complicated to tow.

Shouldn't be a big deal, however, that regenerative braking has to go. Disconnect the positive lug and wire your stay-in-play direct to the MH using the 7 pin. Rather worry about what would happen if your towbar AND your safety cables fail than have uneven braking on the TOAD all the time!

[Mr. October]

Originally Posted by ScottBrownstein

Shouldn't be a big deal, however, that regenerative braking has to go. Disconnect the positive lug and wire your stay-in-play direct to the MH using the 7 pin. Rather worry about what would happen if your towbar AND your safety cables fail than have uneven braking on the TOAD all the time!

I'll have to research how to do that. The Stay-And-Play is connected to the motorhome via a single umbilical.

I find this really annoying. We got the car not that long ago long after Chevy made the update to towing requirements and our dealer said NOTHING. The best part is the owner and the manager at the dealer both have motorhomes they tow cars with and were fluent in motorhomes and towing. We picked the Spark for simplicity. If I have to start adding more cables and/or disconnecting batteries, I may look at something different.

[Mr. October]

I'm going to look more into this solution.
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