Weak charge

[beanmf]

Car was not used much then stopped starting; stored outside. 1-year old battery in place and on a smart tender but no longer shows "charged". Replaced ground cable. Tried jump starting. Replaced ground wire clamp to battery. I sometimes get a light or weak evidence of connection, but not enough to turn the engine over. Ground wire to frame bolt shows some resistance (needle mid gauge). Before I take the ground harness apart and replace the somewhat new battery, does anyone have experience with weak points that might lead to this? I tried searching on "not charging" but am not clear how to search on combined wordings like that.

[jimi]

I'd be suspicious of the battery. Try disconnecting the battery and charge it with a proper charger for at least 8 hours, then see what the voltage is on the battery.

[beanmf]

It should read 14 V, fully charged, right? I did that charge, but will repeat. Good separation of concerns.

[jimi]

Won't be as much as that, anything around 13v should be ok, but not a guarantee, even a battery with a duff cell can show a good voltage until you put it under load, then it will drop like a stone.
Are your battery clamps good and tight when on the battery ? No corrosion on the inside ?

[beanmf]

Battery charged for 48 hrs, reads 13.5 V. Posts are clean; - cable is new; + clamp is new (last thing I did, months ago). Continuity tested from ground to car body and + to fuse block. Jumper cables to a second car which is running. On MR2, no interior dash lights, no fan, no radio, no window motor, but headlights lift up and down easily. Still no noise or clicks from starter, so I'm wondering if a fuse might be blown (perhaps someone jump started this with poles reversed?). If it was just a bad battery, I feel sure we'd at least get some dim dash lights or seatbelt warning sound. Mice could also be a culprit; the car was outdoors the last few winters.

[BYRNEY1984]

Have you checked the fuse link on the battery positive cable. If this has blown or corroded away you will lose everything.

[beanmf]

No, but will do. However, the headlights move up and down willingly

[jimi]

If the headlights go up/down then the fusible link is ok, everything bar the starter power goes through the link. It does sound a bit like a fuse, you might need to start at the battery and follow the voltage, see where it isn't when it should be

[beanmf]

yes, agreed. I'll have to hunt down some electric schematics and hunger for a digital KVM rather than the cheapo analog I have. Fortunately, I've A/C in the garage as it's rather hot out. One car must move outside though. Many thanks jimi. I've never been to Glenrothes, but rather enjoyed our times at Anstruther.

[beanmf]

Help! jimi posted a link to the MR2 electric schematics on this thread but now it's gone. Can anyone put the link back here for me please? Thank you.

[jimi]

We lost a couple of posts with a technical problem, mine must have been one of them.
Electrical diagrams are in the downloads section https://mr2oc.co.uk/downloads/technical-stuff/mk2.html If you can't find relevant diagrams there then check this thread https://mr2oc.co.uk/forum/topic/worksho ... 80372.html and if you still can't find the right ones PM me and I'll have a look through my files