Intermittent dead battery (MX-5 2000)
Discussion
Not sure what is causing this but it's a weird one. It's happened 3x in a year.
For some reason it appears battery just goes dead, or at least that's what it looks like. I can drive it for weeks/months with no issue, then suddenly when I take it for a drive it just refuses to show any electrical activity what so ever. I've solved this each time by simply disconnecting the negative terminal for a few minutes, then it starts up right away as if nothing happened. It will continue to run without issues.
To be clear, zero power, not that he car won't turn over.
The car was not started between October and March, and started up first time when it was put back on the road start of the this month. So don't think there is something draining the battery.
Any ideas what might be causing this? Battery was replaced last year, it's on the original alternator. Was thinking of just replacing battery + alternator and hope for the best.
For some reason it appears battery just goes dead, or at least that's what it looks like. I can drive it for weeks/months with no issue, then suddenly when I take it for a drive it just refuses to show any electrical activity what so ever. I've solved this each time by simply disconnecting the negative terminal for a few minutes, then it starts up right away as if nothing happened. It will continue to run without issues.
To be clear, zero power, not that he car won't turn over.
The car was not started between October and March, and started up first time when it was put back on the road start of the this month. So don't think there is something draining the battery.
Any ideas what might be causing this? Battery was replaced last year, it's on the original alternator. Was thinking of just replacing battery + alternator and hope for the best.
Cable itself may be defective.
The plastic covered earth straps often used connecting engine to body can look absolutely fine at the ends but have rotted away under the plastic.
Check & clean.
If it does it again try connecting a decent jump lead directly from a good clean metal point on the engine to the battery earth terminal & see what happens.
I don't think it's anything to do with the battery or the alternator.
The plastic covered earth straps often used connecting engine to body can look absolutely fine at the ends but have rotted away under the plastic.
Check & clean.
If it does it again try connecting a decent jump lead directly from a good clean metal point on the engine to the battery earth terminal & see what happens.
I don't think it's anything to do with the battery or the alternator.
Edited by paintman on Friday 21st April 16:48
TheLoraxxZeus said:
E-bmw said:
Battery/engine terminal not connected correctly.
Most likely either the one you take off or the other end of that cable/engine earth.
Undo/clean/refit all & it will likely never happen again.
So disconnect wiring from battery to engine, check it all, whack it back together?Most likely either the one you take off or the other end of that cable/engine earth.
Undo/clean/refit all & it will likely never happen again.
The battery is relatively smaii ,and the drain caused by alarm etc is sufficient to flatten in a matter of 3/4 weeks of inactivity ,I know as had the same problem when I first got mine 20 odd years ago .
I now have a Acumate charger permanently installed and whenever the car is parked at home it is on the maintainer.
I now have a Acumate charger permanently installed and whenever the car is parked at home it is on the maintainer.
(but the earth cable attached to it does)There's also an odd "connection" near the battery, which may be past its best.
https://forum.mx5oc.co.uk/t/mk1-corroded-ppf-earth...
https://forum.mx5oc.co.uk/t/mk1-corroded-ppf-earth...
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