So my 83 JDM BJ 40 is late showing up from the shippers , so I start making phone calls . They cant get it going to get it on the shipping truck and I think there may have been some boosting involved . So what did they fry on me by trying to boost it off a 12 v system ??????
Nothing... The system should be fine, just the jump would be ineffective unless they jump the lowest battery enough to jump. If both were dead, they would have to charge (not jump) both bateries and then disconnect and try starting it... 24v on a 12 volt rig, different story...
Either way, I would buy new batteries for the rig when you get it as part of the baselining unless they really test out well and follow the recommendations for 24v batteries on this forum..
Read the ongoing list of battery threads in this section for some data and ideas before dumping coin on batteries.
Don't go to chassis ground on the 24V if you are jumping from a 12V vehicle. Carry a volt meter at all times as part of your kit. Check which battery is low. Battery pole to battery pole only...or: best way to avoid any spark and possibility of battery explosion is to hook up booster vehicle positive post, boosted vehicle positive post, boosted vehicle negative post, booster vehicle chassis ground (away from batteries). Repeat this process a 2nd time to the other battery on the 24V vehicle with a 2nd 12V jump vehicle if both batteries are down. Did I say do not go to chassis ground on the 24V vehicle if you are jumping from a 12V vehicle?
Standard practice with recieving JDMs either they arrive with flat batteries or the car jockeys at the docks dont know how to start them and run them down, when I pick mine up I always bring another 24v vehicle to jump it,I always witness several new owners at the docks picking up their vehicles only to have a dead battery all trying to jump start them.
If they hook the jumper to the proper battery it should not be a problem it is when one battery is 12v and the second is say aprox 8v and the booster delivers 12 you have 32v going to the starter and they dont pre glow then things start to heat up,the first battery should be disconnected first before jumping if that does not work then the battery is dead and you may be able to hook up both and the boost battery and get enough cranking juice, I always disconnect the leads connecting the two batteries leaving the one lead going to the starter and jump 24v from a second vehicle to the battery lead going to the starter.
