thebonster

I searched but couldn't find a similar problem.

2000 4.0HO bone stock. Has been running strong and starting reliably. Drove it last night, no issues. This morning power doors worked but ZERO power on dash, inside lights and no crank. Nothing.

Before trying to jump I put the battery on a meter,12.5v. Terminals clean. Checked fuses,all good. I pulled the ground terminal, re attached and now have power. Started right up as nothing had happened.

Is there a relay that could be bad? The ground looks good (CA car no rust).

Thanks

DFlintstone

Terminals can look pretty good and still have a thin layer of hard crust. Make sure you have shiny lead inside as well as the post, then take it from there.

thebonster

The terminals are squeaky clean.

What confuses me is the TOTAL lack of juice. It seams like there was a relay that wasn't connecting.

xjforfishing

a battery at 12.5 v is almost dead....I would get the battery load tested for starters and go from there....connections.....relays...ignition switch...

DFlintstone

Does it work with a jump? And, There are smarter guys here than me, but no, I don't believe there is a "master relay" or anything like that. There ARE fusible links, sections or wire in important places that will "go open/blow" if shorted enough. Don't think they are intermittent. Blow like a fuse.

Terminals can look pretty good and still have a thin layer of hard crust. It's common there for a little juice to get through, say open locks or turn on dash lights, then go completely open when you hit the starter. Shiney Lead!

thebonster

Thanks for the replies so far.
I've had many vehicles in my lifetime, cars , boats ,cycles but I've never had a battery connection go south over night to the point that it provided NO POWER. Disconnected the ground then re connected and now its all better? I never had to jump it. Is there a anti theft cut out? It does have the keyless entry.

Thanks again

xjforfishing

glad you got it going...I know nothing about any anti theft unless it is after market...

DFlintstone

Good Luck.




.................................................. .................Close, V 12.7 @ 78*
V

Sideways99

are you nuts?
12.5 volts is a perfect charge
our xjs are a 12 volt system
not to thread jack

also re-establishing your ground could have reset your ecm
hence you got juice
check all your connections when you have time clean ur terminals every little bit helps

xjforfishing

I may be nuts I guess, but it takes voltage to push amperage and you aren't going to get much at 12.5....that is the reason that the charging system charges at full capacity around 14.2 v...go out and read your battery before you start your engine and you should get a reading over 13v....if I am wrong I stand corrected....