Checking relay for continuity

Does anyone know how to check a SPDT (5-terminal) relay for continuity to see if it's broken?

I had 4 relays installed....2 for the door actuators, 1 for the trunk, and 1 for the domelight supervision. The doorlocks were only working one way and not the other.  After trying 20 million other things and failing, I finally swapped one of the actuator relays with the one for the trunk, and it worked!  Then, I put the one I took out into the trunk's harness, and then it worked again. So, if the relay is in fact broken, it somehow works for a different application.  I guess you need different parts of the relay for different applications?

Well, with a 5 pin relay, there is a normally open and normally closed contact. now, if power is supplied to the relay, the normally open pin becomes closed with the common pin and NC becomes seperated.  If your confused on what I mean, check this out:

Now, to check to see if its broken or not, you could use a DMM with the continuity feature. You would want to first check to see if there is a connection between pin 30 and pin 87a without any power supplied to the relay..if you get continuity, great! thats working..... (also, you might want to check to see if there is a connection between pins 30 and 87 just to verify that there should be no continuity) now supply power to pins 85 & 86...you should hear the relay click..now check continuity between pins 30 and 87...if ya got it, great. your relay is in working order.

You could also check continuity with a light bulb or something....

Also, to help answer your question on the different applications, YES it is possible to use other parts of the relay for things..it all depends on wether the applicationg needs a normally open or normally closed connection before while power is supplied to the relay.

Hope this helps!

Wow, thanks for that help sparkyssb, that was pretty informative.  I'll go ahead and try that and see if it is in fact a dead relay (although I'm using it for something else and it's working fine, so maybe I won't replace it  ).

Thanks again!

No problem!  Keep us updated.

Hi sparkyssb,

I checked all of my 7 relays in Plymouth 94 and none of them worked: the pins did not move once power was suplied - it seems like my problem (can't start the ignition) is not in relay. Do you know, what could it be?

I remember, I always had a ploblems with power... Once after long driving all door locks started to dance - just up and down - may it be a clue?