Team, I have a Ford Focus MK4 2021 Vignale parked up for long periods in Spain. I have a 30w Solar charger that I can connect to the OBD port. My question is does the OBD port stay live allowing a charge to the battery, or does it switch off after a while like the cigarette lighter port. Cheers 👍 posted in General as may apply to other models 👍

This sounds dodgy to me, why can't it be connected directly to the battery so any charge would be measured by the sensor on the negative (if fitted)?
Appropriate protection, fuse, controller required?

I would need to run a cable through the bulkhead as the panel is in the inside of the car. I have it rigged now. Panel output on pins 16 & 4 of OBD cable 14v. Voltage on battery is only 12.6v. there must be something fitted to prevent reverse power back to the battery. 

This is not going to work.

Modern Ford models (Focus MK3/MK3.5 and MK4/MK4.5) have a DC/DC converter to power the delicate electronic CANbus modules. On the Focus MK4/MK4.5 the OBD module is also a CANbus module.

You are now putting power on the output side of the DC/DC converter. Something the circuit is not designed for. This can cause loads of problems (including failure of the delicate electronic CANbus modules). Especially when using an unstable charger (which most solar chargers are).


I strongly recommend to disconnect the charger from the OBD port immediately and connect it properly. This can be either directly to the battery or to a permanent power supply.

I do not know the Focus MK4/MK4.5 but on most Ford models the 12 Volt socket in the boot has a permanent power supply.

7 minutes ago, JW1982 said:

This is not going to work.

Modern Ford models (Focus MK3/MK3.5 and MK4/MK4.5) have a DC/DC converter to power the delicate electronic CANbus modules. On the Focus MK4/MK4.5 the OBD module is also a CANbus module.

You are now putting power on the output side of the DC/DC converter. Something the circuit is not designed for. This can cause loads of problems (including failure of the delicate electronic CANbus modules). Especially when using an unstable charger (which most solar chargers are).


I strongly recommend to disconnect the charger from the OBD port immediately and connect it properly. This can be either directly to the battery or to a permanent power supply.

I do not know the Focus MK4/MK4.5 but on most Ford models the 12 Volt socket in the boot has a permanent power supply.

Thanks for your advice buddy. Disconnected now, would be great to be able to make cigarette lighter permanently live 👍

This is very interesting.  I have a solar panel plugged into the OBD socket on a Mk7 Golf without any problems.  Had no idea it wouldn't work the same on a modern Ford.