Battery negative wire

It doesnt really matter how you do it, but both the battery and the block should be earthed to the chassis.

Generally they both go to the same point but itdoesnt matter as long as the points you connect them to are nice and clean and solid.

The block needs to be earthed as the starter and other things just earth directly through it.

bracket for

If I remember correctly Greg, on my 109 there was an earth braid from one of the starter moter bolts to the chassis. If it is not there you are in grave danger of your speedo cable outer going up in flames.

AWEM

Not really, the choke cable acts as an adequate if not wholly satisfactory earth, well it has in the past for my Series 1.

Gordon

The battery -ve should go to a bolt under the battery carrier. The block should be earthed from the (usually) starter motor fixings to the chassis, adjacent to the starter. As observed by another post, if this is not done then the earth will try to find it's own way home via any connection, which could be the speedo cable etc, or worse via the gearbox which is Bad News as current flowimg through all the interesting different metals does wonderful (i.e. expensive) things.

It is also quite common for the earth to not be able to find a way home at all, which will result in bad, or non-existent, starting. If I had a pound for every time I could have sold a battery, alternator and/or starter to cure a bad earth....... ;-)

Richard

ROTFL. I 'fixed' a friends mini back in the 70s replacing the dried out, seized up throttle cable with a new plastic shroud type and the pedal went up and down beautifuly until we turned the key when it all went up in smoke.

No engine ground strap.

nigelH

Greg came up with the following;:

Best thing I ever did on my series 3 was to replace the earth straps with one from battery to engine block, one from battery to chassis and one between engine and chassis.

Probably way overkill, but it definitely stopped all the little 'gremlins' we'd been experiencing.

Several 101's have fallen foul of the handbrake cable welding it's self to the case due to failed earth connectors.

If it'll do that then bung a couple of more on.

On my IIa there was a earth by the gearbox too I seem to recall. I also ran one to the Chassis and the Jag block when I fitted the jag lump.

Lee D

In message , beamendsltd writes

Yep, everybody blames the battery.

My FIL had an Austin 1100 once which had a history of bad starting problems. Most days it would be fine, but then suddenly for no apparent reason it would fail to turn over. Nothing, absolutely dead.

I too fell for it and bought a new battery, only to have the same problem a few days later. Had another check of the earthing leads and this time gave an extra tug and felt a very slight movement. Took it off and immediately spotted the problem. The car had been under-sealed from new (An Option in those days). A small blob had come through the fixing hole and so the earth braid was bolted down on to it, not making a clean flat contact with the metal. Over the years water had seeped in and it had corroded. Cleaned it up and never had another problem.

Had a similar problem with my 90. The earth braid was crimped onto the terminal. Again just a very slight movement detected. Local Auto-electrician recognised the problem immediately, and soldered it up for me. No more problems.

It's also worth feeling any of the high current joints after a session of "failed to start", any that are even slightly iffy will be warm. Ones that are definately iffy could be HOT so take care...

Thanks to all who replied, I have finally found the remains of what was once a braid from starter to chassis so it appears that someone's 'fix' was to move the negative lead straight to the block. I'll get it replaced as part of the rewire.

Greg

Goodrich SS brake hoses also provide a satisfactory earth return path - at least they did when one of the battry straps on my RRC decided to see how many times it could wrap itself around the steering column - oh and so did the +ve supply to the rear lights and the throttle cable sheath.

The brake hoses showed no sign of damage until the lining of one burst at an MOT test some months later. Apparently the heat had melted the hose almost to bursting point and it eventually failed.

Richard