Although in the past I have jumped a 6 volt car with a 12 volt car and not had any problems I'm not sure with my 52. Does the positive ground have an effect ? I'm thinking that this might blow something in the electronics of a newer 12 volt vehicle. Should I worry, or just pull the 12v battery out and not have it connected to the vehicle ?
Thanks

 

With A (+) ground the best way to go is with a JumpPak. A jumpPak better in any case so to protact both car/trucks, (-) ground or (+) ground.. U can just reverseing the jumpers can do some real damage to the new car/truck computer if it takes a shock..

 

As long as the vehicles are not touching and you connect + to + and - to - it will be no more of a load than a negative ground system.

Where you run into problems is with dirty terminals/cable clamps and lots of arcing. Some modern vehicles are more sensitive than others so if your owners manual specifically warns against jumping then dont try it.

 

Years back I did a guy in a service station a favor and jumped his car. I wound up having to replace the Alt, Regulator, and computer on my car. Never again will I jump without first disconnecting my terninals, its just not worth the chance.

 

I have jumped many vehicles with my vehicles over the years and have never had a problem with any damage to anything. This includes a number of 12V to 6V jumps.

You can jump a 6V positive ground vehicle from a 12V neg ground vehicle as long as the cables are connected + to + and - to - AND the vehicles are not touching. Be very careful to only use the starter for short periods since the 12V can cause it to overheat. Make sure you do not have ANY lights or other accessories on in the 6V vehicle. Applying 12V to a 6V bulb turns them into flashbulbs. It is hell on radios also. Your cables may overheat quickly also since the 6V starter will draw a HUGE current from the 12V battery. Make sure you only connect the jumper cables when the starter is engaged. Use only high quality #4 or better copper cables, none of the #8 or #10 cheapo aluminum units. Do not have the engine running on the 12V vehicle either while jumping. The extra couple of volts will not be needed and you do run more of a risk of damage to the 12V charging system. This is a greater concern on the new vehicles with small frame high output alternators. On those junkers even charging a dead battery will burn up the alternator.

 

Another way to boost a 6 V system with 12V is to connect your booster cable positive from the 12 V battery to the starter side of your solonoid, then connect the negitive cable from the 12 V battery to the frame or engine block of the 6 V vehicle being boosted. This bypasses the 6 volt system entirely except, of course, the starter. Take care when connecting the booster cable to ground that it is not near the battery because a spark could ignite any gasses that may be present.