Ok, so a little back story...

I have a alt from a explorer and a serp set up, mustang EFI, and a Moates QH tuner. I have a red top battery that has been going bad for some time. In November when I needed to move the bronco across the street for storage and I had to jump it as the battery. I had not driven it for about 8 months before that time. I jumped it and move it to the neighbors to be stored as the garage door at the new place is too short and the bronco will not fit (Nov). After it was jumped it ran fine.

Today I went to fire it up and it would not jump start. I disconnected the neg cable and then tried to jump it. The fuel pump ran for a couple seconds, dome light worked, and you could tell there was power to the rig. Tried to jump it and the starter solenoid would only click. I was guessing it wasn't getting enough power thru the jumpers so I added a second set in parallel. That carried enough power to get it running (I have never had to do this before). I then disconnected the jumper cables and the rig died. I tried this a couple times with the same result. I then took the alt to Advanced to have it tested. They said it was bad. I bought a new one and installed it. ...same result. ???

I know the red top is bad and I want to take it to Interstate and have the largest battery installed that will fit. But I can't keep the rig running. I am wondering what gives??? Any ideas? Anyone with the day off want to come give another perspective? I would love to get it up and running to make a meeting here soon! ...and enjoy for the summer.

Thanks guys!

I've seen this quite a few times with BMWs the battery draws all available power. Replace the faulty battery & recheck your charging voltage.

Agreed the battery is toast and will need to be replaced.

When you say Red Top do you mean a AGM type battery?

Did you get a voltage reading on the bad battery?

I bet it was below 10.5...


There is a fix for that...