Earthing Strap - where does it go?

[Tony Hunt]

Electrics or Engines?

I took my starter motor off the other day to clean out the pre-engagement solenoid that was sticking occasionally.
I was very disconcerted to see an earthing strap on the upper mounting bolt dangling free! Not only that, I looked everywhere and couldn't see where on the chassis the other end was meant to be bolted.
Any ideas? I have a factory-built GTD, so it must have been bolted on somewhere; there are witness marks on the terminal to show for it.

Tony Hunt

[Paul Thompson 'Hooligan']

Hi Tony,

An earth lead only needs to go between two sound points, one end to the motor/gearbox and the other to the chassis. You might be able to tell where it 'had' been as the point on the chassis will often have had some surface paint removed to aid a low impedance connection.

You might also have another somewhere else which would have helped if this one has been off for a while. If you try to crank the motor without adequate earths fitted, the current will generally find other routes, not possibly suitable and I've seen a throttle cable 'smoke' before where an earth had failed..

Hope you get it sorted ok.

[Dutton]

Tony,

I'd be real tempted to have a close look for the other half of the connection at the motor mount... should be fairly close to the starter.

Good luck!

T.

[Brian Magee]

Tony,

Have you tried fitting the strap to the other starter mounting bolt to see if it will reach then. It may have been fitted to the wrong bolt. As you have a second strap between a gearbox mounting rubber it is not really necessary.

Brian.

[Cliff Beer]

Tony, definitely make sure you have a good ground strap between chassis and engine/gearbox - bell housing is common attachment point. I've seen engines run poorly because the ground strap has failed/corroded and, worse yet, the weak ground is often running through a path that includes bearings, causing premature wear/failure. If you have a good ground strap then you can just connect that ground strap to somewhere on the block or elsewhere in the vicinity.