Kinda dumb question, but what's the best way to test a 12V relay? With a meter on the switched side, do I just wire-up the coil side to a car battery? Do I need a load on it? Am I gonna fry it?
I would normally just try things like this, but Toyota doesn't make this relay anymore.
The relay has two field wire(small ones) and two main wires(bigger one).
If you take your meter and set it to ohms. You should have continuity thru the field wires. It should not be 0 ohms or infinite. I think a couple ohms of resistance should run the solenoid coil.
The main wires will have no continuity. When you add 12 volts to one of the field wires and the other field wire to ground you should hear the relay click. Then with power on it, take your meter and see if there is continuity across the main wires.
The field wires are the switching wires, they control the plunger or contacts in the relay. When energized they make the relay become close(allowing electricity across)
Some relays are opposite and when the field is energized the contacts are broken.
As long as you think of the relay as a remote switch, and the field wires as the control it is easy to check.
The field can sometimes short out. As well the main contacts can burn out too.
When the field is energized the main wires should have a resistance number of 0. Meaning there is no resistance, and current can flow directly thru the relay. If it has a few ohms resistance than the contacts are burn out.
Thanks, that's what my plan was, but the relay isn't in the car, nor is the battery. Can I just wire a car battery to the field contacts (with some alligator clips and scrap wire), or do I need more resistance in that line?
