Thread: Engine earth straps?

you need at least one strap that connects the engine or transmission to the chassis or to the primary earth strap from the battery

it helps elminate stray voltages and makes sure there is a good connection for the startermotor so she fires up correctly and all your gauges read appropriately... Oh it also helps out with charging the battery.. Its important as the engine/gearbox sits on rubber mounts with no direct link to the battery other than through the drive train and the handbrake connections.

As Dave says - you need to have a strap connecting the engine and chassis electrically. Without it, the engine and drive train are largely isolated electrically from the chassis and body - the only electrical path between them is via the propeller shafts, gearbox/transfer case bearings, diff bearings and springs. This is a fairly chancy connection, depending on how rusty the spring seats are and how oily the various bearings are.

If significant currents flow in this circuit, it is not very good for the bearings either.

The noticeable effects will vary depending on where the battery earth strap goes - if it goes to the engine or gearbox, it will start fine, but you can expect weird electrical faults with just about everything else. If the battery is earthed to the chassis or body, then you can expect poor starting, and strange faults with any electrical devices on the engine, including ignition and gauges.

I suspect you have an engine earth strap or equivalent but don't know it. (equivalent would be the battery earthed to both engine and chassis or a strap from gearbox or transfer case to chassis).

John