MG Magnette Forum

What is the correct location for the Battery Earth / Ground Cable - on my recent purchase it is to a metal bracket on the cylinder head - never seen that before!! and due to a ne knee I can't get under it (YET) to see - always had earth / ground cable going to the body (where on a ZB?) and then from the chassis to the drivetrain....
Everything works so clearly there is a drivetrain to body cable somewhere - but given the quality of the fitting of the new loom, NOTHING surprises me - horn & indicator switch not connected, and indicator warning light cur off at relay and shoved behind the trim at the dash end!

One the cars I have, and have seen, the ground for the battery attaches to the battery box itself, on the (as you're looking at it) left side, the side that's opposite the starter relay.

As Wray says side of the battery tray frame and a bonding cable between the mechanical fuel pump blank plate and the left outrigger, beneath the carburettors.

Appreciated

Ground to battery box.
But my engine gets ist ground via a strap between lower bellhouse screw of the gearbox and left side to a screw at the crossmember were the front axle attaches too. Need to check which bracket i used. But no idea if this is original. My mga bridges one of the engine mounts.
Simon

Thx - looking forward getting under it and looking
3yrs into a Big Healey Restoration as well and soon be time to go under that two and start running the main battery cable Rear to Front and Grounds.

That's where mine is too Simon..

Not for the electrical wiring purist/restorer.

The starter motor has the greatest electrical draw of any component on a z series Magnette. Fitting a heavy earth/ground strap directly to clean steel on the bellhousing makes the most electrical sense in combination with a similar sized earth/ground strap from the relevant battery post or the bellhousing attachment point directly to clean steel on the chassis.

If the engine won't crank properly (with a viable starter motor and battery) and you notice the choke cable glowing red hot...then that's the result of a bad earth/ground to the engine block. Consider that the engine is rubber mounted and that rubber doesn't conduct electrical current.

Bad Earth/Grounds are the bane of many classic cars electrical systems. It's best not to be precious where paint and Earth/Ground connections are made to the car's steel chassis/monocoque if you really want efficient and reliable electrics.



Edited 1 time(s). Last edit at 2024-04-18 05:18 PM by enigmas.

Mine has this ground here too Simon..