Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Battery Isolator installation

Proposing to install a battery isolator switch, primarily for when working on the car and also for security purposes. The type with the removable red handle.

Question is, which of the 2 red wires behind the rear bulkhead do I break into? Is it the larger wire or the smaller wire?

The smaller wire goes into and returns from a plastic housing near the battery. Anyone know what this housing is for?

Pic below shows the housing.

The housing is the master fuse - between the battery + and the roll hoop.

The main red feed in the Morgan I've had has always emerged under the dash on the right hand side at a connection post. That would be a convenient place to fit a master switch.

Which type are you using?

The basic off/on one or the competition type Automec one?

If the latter then there's more to installing them than just cutting into the battery feed cables, you will also need to wire it into the ignition feed as well as including a resistor into earth feed to prevent a damage to the alternator

Arwyn

I'm very new in owning a Mog, however, it does have a battery isolator installed which I believe is a basic on/off located behind the driver's seat.





Rgds
Lumpy

Thanks Dave - often wondered where the master fuse was! Surprised its not in the main fuse box under the bonnet.

Cheers Lumpy - that's the kind of thing I am looking to fit. Looks like a direct insert into the large positive battery cable.

Hi Arwyn

Have looked at competition isolators with several terminals to pick from. However, wiring into the ignition feed and fitting resistors sounds like A-level stuff to me. Is there a numpties guide specifically for Morgans anywhere? What's the advantage of a competition isolator over a basic off/on switch?

If you are going to isolate the battery you need to interrupt both the red cables connected together at the battery positive terminal. I would suggest you re-position the two red cables to connect together at one of the terminals of the battery isolator. A short fresh cable of at least the gauge of the thicker (starter feed) cable and with appropriate eye terminals would then run from battery positive to the other terminal on isolator.

Thanks for this Richard - I follow the logic

A lot depend on how far you want to go…. But just a random thought! If you look closely at the fuse holder below it appears to be a panel mount device. It wouldn’t be inconceivable to make up a little sheet metal braket or use the back of a small die cast box with a rectangular hole to mount the fuse holder, all screwed to the back of the heel board. No wiring mods and with an access hole through into the car, just lift the carpet and whip out the fuse to isolate or immobilise.

Roger, I notice you've packed out the top shocker mount which as standard are at a nasty angle, good simple mod that most owners miss

Not one but two good ideas!