I am still chasing a weird charging problem on a 1990 240. With a known good battery, and a good alternator giving 14.15 volts at the posts while running, I am still having a weird charging problem with this car. I posted about this a few months, and two surgeries ago, so please, any help would be appreciated, I am in dire straits with this car, as I have to get it running, and am in no shape to work on cars. If I have a short to ground, is there any I can isolate it without having to look at every wire? Is there a few spots that I can check without going through everything? I troubleshoot ground faults on fire alarms, but I am not sure where to start on a car. I have metered between batt+ and the alternator ground, and have 0 ohms....

This car seems to run for a while and then eventually won't start because the battery gets too low to crank it over. It all started months ago, when the battery light would stay on until it was brought off idle. I knew something was up w the charging system then. It would not charge while the battery light was on, and when brought off idle, then it would charge at 14vdc. But, it eventually wouldn't start. I swapped in a used alternator or two, replaced broken or burnt dash light bulbs, had 14v at the battery posts, and it ran for two months

Then, last week, it wouldn't start again. I swapped in a known good battery, and it had 14vdc at the posts, and I sent my stepson(his car) on his way, telling him it is charging and it should be fine. The next morning he rolls in before work, gets in the car to leave, and it won't start. Now he is driving one of my vehicles which I swore would never happen (long history of trashing cars) and I want him out. PLEASE HELP, I believe one of the reasons for my recent gut surgery is from stress over his cars over the years, and I have to get it on the road!!! Yes, I am putting him to work on it, but I have to hold his hand, but he is doing the work. Thanks for any help on this problem.