Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Power suppl when engin is running

Has anybody found a power supply that is only alive when the engine is running, it only needs to be suitable for activating a relay. I tapped into a wire on my 200 series Toyota Land Cruiser to activate the dual battery manager. I am looking for something similar on my Duratec
Colin

Easy enough to find one that's live with ignition, but when the engine is running is a bit trickier. I can't think of anywhere that only comes alive once the engine is turning over. Maybe a sensor on the alternator output triggering a relay?

The radio is usually only on when the ignition is on but as Tim says only when the engine runs is harder. I can't think of an easy source,

Bit like I was recommended for a fuel pump, perhaps something that is switched on by action of the oil pressure switch.

http://www.fae.es/en/products/oil-pressure-switch

Try somewhere like this (but closer to home 🙂) ..... they have normally open oil pressure switches in their catalogue .... with a T piece to run the second switch you could put an ignition switched +ve onto one side of the relay coil and use the switched earth of the new oil pressure switch to operate the relay and switch the 'engine running' supply you need.

Bit of a faff but it would solve your problem ... and it's not that easily solved using anything on the normal car loom

K

The usual trigger for dual battery charging is a voltage sensitive relay triggering on say 14 volts or above. This is better than an engine running feed as it won't trigger until normal car battery has reached a reasonable state of charge. Google same or check out eBay.

Do check the relay contacts are more than adequate to carry the maximum charge current to second battery though.

Richard ... my thoughts as well ...... a battery relay would be straightforward to connect (and the instructions would be with it or easily found on the web) .... the wording of the OP seemed to indicate that the feed was similar in function but for something else (hence the suggestion for a clean-switching alternative)...or maybe it's just me over-thinking again 😁

K

I am thinking of fitting a pair of spot lights, Ionly want them to work when on main beam so can I connect them directly to the main beam feed or do I need a separate feed through switch and relay

I'd use a relay, but take a tap off the main beam feed to switch it.

Feeding them directly from main beam will require fuse rating increase Keith but bare in mind that newer models are fused independantly left and right. It will also increase current loading on dip switch so using a relay in this case is a better option.