fridge van ign on wiring

Hi there ive got a merc sprinter fridge van and i need a way to wire up the ignition so that when i start it up i can flick a switch and the ign will stay on when i take the key out and also need the so when i press the brake it cuts out Any help will be much appriciated Ashley

ashbash171 wrote: Hi there ive got a merc sprinter fridge van and i need a way to wire up the ignition so that when i start it up i can flick a switch and the ign will stay on when i take the key out and also need the so when i press the brake it cuts out Any help will be much appriciated Ashley

pulse on pulse off

a push button to turn it on and the break switch to turn it off

John DeRosa (Hotwaterwizard)

Stockton California

When in doubt, try it out !

hotwaterwizard wrote:

That'd do it, but the diode up top needs to be flipped around to latch-

Many thnx john but i am not clued up on relays, car electrics fine but relays not, could you simplify for eg where it says latch unlatch?????? kind regards ash

Many thanx for that John, will try it at weekend and let you know how i got on Ash

If the latching input is momentary, what keeps the coil of the left relay on when it's removed? If the diode is placed as shown, it would block the current from the 12V input from flowing back through the 87A-30 contact path of the second relay, which is needed to latch the left relay. If you want to isolate the load, you could put the diode in series with the output rather than between the relays, but then you'd have to make sure the diode is sized to handle the load. Might have to be pretty hefty if it's a fridge. Doing away with the diode altogether would be another option. I wouldn't think the load would source 12V, so it really shouldn't be a problem.