First post and glad to be able to find this forum. This unit, cat 257b turbo high output, seems to have a issue with draining the battery down over the period of a few days. When pulling and replacing the battery cable back on the battery I can see the smallest spark upon connection so I know something is drawing power. I've hooked up the battery and pulled some of the fuses in the fuse block under the drivers leg area. With everything off (unless I have something in and don't know it) I do get some voltage "across" the fuse connectors. To me this would indicate that the item fused had some voltage draw on that item. Has anyone else experienced this and do you think this is a good way to troubleshoot where the issue is? It seemed from memory that there were 2-3 fuse ports showing a voltage across the connectors. These were also right next to each other which just now makes me think that it could have something to do with the fuse block itself. Ideas? Suggestions?thanks. Phil
The spark can be misleading because lots of electronics will cause that spark initially but not draw enough current after the initial "charge" to drain the battery in a reasonable time. It sounds like you're on the right track, but you need to either measure current across the fuses, or disconnect them and figure it out by trial and error. The other possibility is the alternator has a leaky diode, since the alternator doesn't have a fuse (except a fusible link) you have to disconnect it and use trial and error to eliminate it, or measure the current draw back through the alternator.
Thanks for the suggestions. Did not know about the initial charging of electronics that could show a spark. If after a few minutes of charging if the battery were then removed and instantly place back should the spark still happen? I'm thinking of removing the fuses in question to see if the spark is still there. Would it be possible to check the current between the battery terminal and the battery to see if these electronics drop out after a bit?
Yes, on most any car these days there's a small spark when you connect the battery, take it away for a couple seconds and it will spark again when you touch it again. Yes, you can check the current between the battery cable and the battery terminal, just need a multimeter that can handle whatever current you expect (one amp? 200mA?). If you have a good multimeter (not one that cost less than $3) then it should have a fuse to protect it from overcurrent, a pain to change but better than frying a GOOD multimeter. There's not that much on most equipment, leaving it sit with something else disconnected each time will figure it out before too long. You have checked the battery by leaving it disconnected for a few days to see if it holds it's charge, right?
My brother had a 277 that did the same thing, ended up being the radio. You need to unhook the wires to see if that helps , pulling the fuse didn't help.
Thanks for the info,... now i'm wondering why pulling the fuse did not help him.
It's a week later, did unhooking the radio help or not? Good to post results so others know. Steve
Mountanlake. This one does not have a radio. I do see an old antenna off the backside of the cab near the top. Not sure where the radio was.