the circuit runs at 20amps

the biggest one i can find is 1amp from maplins

could u put it between the alarm and relay as this is only 1 amp?

i'd def put a diode on the relay mate, just in case, and to be honest for the price of a diode i do it on all circuits i make with a relay in just for protection of the relay if nothing else

why do i need a 2nd relay? can u draw it lol

if the solenoid wont work with out a relay then yes if thats the case
put a diode between the alarm relay and solenoid and a relay between ptms ans solenoid

do i need a 2nd relay for the push to make switch?

or do you need the realy in with the push to make switch to operate the solenoid?

in that case the power feed from alarm put a diode there so there is no feedback from the relay

id say from that diagram put a diode between relay and solenoid so when you push the to make switch no power gets to the relay or the alarm

ok where to start..........

i have my alarm set up so that when i press a button on my key fob it sends a 0.8 second pulse of electricity to the relay from the alarm to open the relay and allow the 12v from the battery to pass thru the relay to the solenoid and pops the door open. the solenoid is earthed ok

this is set up fine at the mo

i plan to add a 2nd manual push to activate button which will over ride the alarm/key fob. this will have a seperate 12v live from the battery, going to the switch, then to the solenoid and then earthed.

BUT

the last thing i want is power traveling back up the wire from the relay to the solenoid IF it will get through the relay and into the alarm, as this may damage the alarm.

First off will the power go back into the relay? And if so, will it be able to get through the relay even though there will be NO feed from the alarm to open it?

If YES then do i need a diode, and if YES again, will i be OK wiring one in between the alarm and the relay (1amp) as after the relay is 20amp and the diodes i have are too small

MANY THANKS!! on this

marv