That's a rough description. 2004. Twice this has happened in the last 10 day. Computer battery is charged! As far as I know the main battery is charging normally. We stop the car using the sequence parking button then engine kill button We go to start it and the panel is dim and the alert triangle appears. As i try the sequence to start the panel dies and all electric systems go off line. A jumper to the under the hood points revives the system? As I said the small computer battery in the trunk space is holding 13 volts. Ideas?
No it isn't. Even new they won't "hold" 13 volts. But it sounds like you have a bad connection somewhere......at either end of one of the main battery cables or maybe even inside the battery. The far end of the negative cable where it connects to the frame/body is often a problem.
Hum well its holding the max charge. It is only about a year old. Will check the leads. Where would the far end be? Back where the batteey sits or somewhere up in the engine compartment. Thanks for responding
The positive terminal of the battery is connected directly to the underhood jump point, using a long cable. Of course, there is a 120 amp fuse installed in the positive terminal fuse holder assembly.
You really have no good way to know that "it is holding it's max charge". And brand new batteries sometimes fail too. The exact location of the main battery cable connections probably varies some by year and model. Trace those fat cables and SEE where they go........or consult a Toyota shop.