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

Aren't battery isolaters on the neg side normally?

A direct insert is the safest option if DIY is the approach, sourcing the correct cable capable of carrying the current associated with all the load on the total circuit is tricky if one is not trained as sparks. OHMS LAW comes into play in conjunction with cable cross sectional equations, getting it wrong can cause over heating and fire.

Rgds
Lumpy

Ah yes the shock mounting! It’s all a bit of a compromise
The leaf springs are mounted at an angle so the axle moves up and down 6 degs off from the vertical. No surprise the damper bushes squeak……

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?[/quote]

The competition isolator switches will isolate both the battery and the ignition circuit. They will stop everything dead.

The basic type will only isolate the battery and it's possible that the engine will keep running on the alternator! - theres a story about a trials competitor whose battery fell out the back of his two seater on an uphill section. The car kept running until he came to restart it!!!

Arwyn

Chris, the competition switches are commonly know as ‘FIA’ type, recommended as Arwyn says.

Old style thinking which falls into the "we've always done it that way" category without being aware of the consequences particularly for boats. See here.

Similar flawed thinking was the US based trend for positive earth systems many years ago.

Mine's located between the seats or at least it is when the seats are in the car. I replace the red key with the cut down black one in the second photo when I'm touring which is practically invisible.

Mine's on the negative terminal and even now I know better it's staying there.

I read the the bit about boats....that I agree with, but cars are different. I have done a bit of checking and it should be on the neg side to prevent spikes, which can damage the diodes in your alternator or ECU.