Auto Electrician here ?

Hi .. I have a EA Fairmont that got a flat battery from a indicator light being stuck on overnight from its alarm.
I charged the battery to start the car and took it for a 15 minute drive too charge it back up ,I left it running in the driveway and it cut out on me.
So I decided to go get the new battery ,I fitted it and everything seemed fine and fully charged. Tried to start ,and wouldnt fire up ,Im getting no problem from the battery,starter, or alternator and only can think its a relay switch.
I am wondering if anybody can advise me how too check a relay switch ,and with what tool will I need to buy to do this.

Cheers in advance

Jono aka jj

[M14A-Mclaren]

Multimeter or just an ohmmeter, It depends if it is a normally open or normally closed relay. You'd need to energise to relay coil, terminals 85 and 86 and then you'll need to test the switching contacts 30 and 87 to test it for continuity or if its and ohmmeter, you'll get an infinate reading when the contacts are open or a small resistance when they're closed.

If its a normally open relay when you energise it you'll get contunity beep or a small resistance over the switching contacts and you should get nothing or infinate resistance when you test the switching contacts with it not energised. If its a normally closed relay you'll get a continuity beep or small resistance when over the switching contacts when its not energised and you should get nothing or infinate resistance over the switching contacts when it is energised.

To energise it you could probably use a small battery back, with about 8 or 9 volts.