Battery Disconnect

[bayoubelle]

We have a battery disconnect switch on the positive terminal of our 2016 Ford Focus. When we switch this off shouldn't we be loosing all power?

We noticed when it is in the off position we still have lights on inside and outside the vehicle.

[bayoubelle]

I will have to ask about the diodes, we too have the SMI. We didn't notice this issue before the dealer rewired the break away switch to the SMI box. We called Ford and spoke with someone that said disconnecting the positive would work also, since we need the negative for powering the brake.

[georgelesley]

I would ask the installer if they used diodes in the rear lightng circuit to prevent backfeeding of voltage from the mh that activates the brake supplemental system our SMI braking system specifically requires the negative post to be connected as it uses it for the ground.

It is essential that diodes be used to prevent backflow. The transmission will likely be damaged if not. I would suggest you NOT tow it until you get this answered.

[RedRollingRoadb]

Well, maybe that is why Ford says disconnect the negative cable.

On my Focus I toyed with putting the disconnect on the positive side as it was easier to do. Decided to put on negative that way Ford couldn't say it wasn't done per their instructions.

Some users say it makes no differance and I agree except as you have found out. Some say it is to be certain there is no stray voltage to the transmission causing it to kick into gear. My idea that the hood is really close to my switch so it is a CYA thing.

It sounds like you had it done, ask them why they didn't follow simple instructions that are found in the manual, then ask them if they will buy you a new transmission if the worse happens due to their fault and it gets toasted. I bet they will give you dumb looks and say "that's the way we have always done it." I'll bet they screwed something up.

And I would be looking at the lights too very closely if the did that wiring too.

[rk911]

eieioh wrote:
Responders, Please, note the vehicle in the question is a Ford Focus. I don't think it would have a chassis and House switch.

oops, you're right. i totally missed that and ass-umed we were dealing with a motor home.

what does your owner's manual say about the switch?

[eieioh]

Responders, Please, note the vehicle in the question is a Ford Focus. I don't think it would have a chassis and House switch.

[rk911]

bayoubelle wrote:
No, we were still in garage. We wanted to be sure the disconnect was working since they did some rewiring. We have always been outdoors, so we never noticed if the lights still worked after we disconnected the battery.

hmmm. ok, tell me this. are there more than one disconnect switch? if you have two you want the one labeled 'coach'.

the switch is likely a momentary contact type...you push and release. there are two types...single and double poles. using the single pole type you push the same end o ce for off and again for off. we have double pole switches. we push one end for off and the other end for on. if you have this type of switch try pressing the opposite end and see what happens. the switch might be mis-labeled.

[bayoubelle]

No, we were still in garage. We wanted to be sure the disconnect was working since they did some rewiring. We have always been outdoors, so we never noticed if the lights still worked after we disconnected the battery.

[rk911]

bayoubelle wrote:
We have a battery disconnect switch on the positive terminal of our 2016 Ford Focus. When we switch this off shouldn't we be loosing all power?

We noticed when it is in the off position we still have lights on inside and outside the vehicle.

are you still connected to the electrical post? if you totally disconnected and you have pushed the correct disconnect switch (our MH has two...one for the chassis battery and another for the coach batteries) and you're still seeing coach lights or other 12v accessories then you've either pressed the wrong switch or it's not working.

[lryrob9301]

bayoubelle wrote:
We have a battery disconnect switch on the positive terminal of our 2016 Ford Focus. When we switch this off shouldn't we be loosing all power?

We noticed when it is in the off position we still have lights on inside and outside the vehicle.

Are you connected to your motorhome via the umbilical cord, or a toad charge wire setup???