I just got a TM for my boat. It is a 24 V Bow mount. I also just installed the on board charger. Do I need to disconnect the jumper cable to the TM batteries when charging?

The boat has the factory installed TM plug (2 prong male). I found the female outlet inside the rod holder when I purchased the boat. The previous owner never had a TM. How do I know if the outlet is for a 12v system or if it can handle the 24v?

YES Disconnect the TM before you charge the battery. The TM constantly draws on the batt whenever it is plugged in. It won't "damage" it to leave it plugged in, but you won't get the most out of the charge, and you will generate unnecessary heat on the terminals. I disconnect mine whenever it isn't in the water.

As far as the boats electrical system, you need to find out what gauge wire is running on those plugs. Newer boats would be like 4/0 or possibly 2/0 to handle the 36v TMs. I would say you need 4/0 for 24v. I have 2/0 running my 12v motor (55lb PowerDrive) and all the lighting on my boat on the same line. It's PLEANTY of cable for that draw, but I know it won't be heating up any time soon.

what about the jumper that goes from the neg to pos for the 24 v system? should i disconnect that jumper?

I just got a TM for my boat. It is a 24 V Bow mount. I also just installed the on board charger. Do I need to disconnect the jumper cable to the TM batteries when charging?

The boat has the factory installed TM plug (2 prong male). I found the female outlet inside the rod holder when I purchased the boat. The previous owner never had a TM. How do I know if the outlet is for a 12v system or if it can handle the 24v?

NO you do not have to take the jumper wire off before charging the batteries.

The plug will work just fine if it fits the male unit.

I always unplug the t/m before charging and even when not charging.  Heres one reason why.

I have a bow mount T/M (hand controlled). Someone accidently turned the handle to ON, causing the prop to rest against the bow of the boat, unable to spin.  The motor got VERY hot but luckily was not damaged before I noticed it.

unplug the TM

If your using a portable charger, disconnect the jumper.  If your using an onboard multiple bank charger, you should be able to leave the jumper.