Testing my relays.

So I was pointed in the direction of checking my relays when my power door locks, radio, and dome lights stopped working.

I bought an analog multimeter today for 10 bucks and having zero experience with this stuff, did a little googling and searching here.

So this is what I understand:

My relay diagram shows a relay for POWER LOCKS: LOCK, a relay for POWER LOCKS: UNLOCK, and a relay for Radio Illum. Does this mean a light over the radio, or radio and illumination, as in dome lights??

Moving on, I pulled all three of them, and have found that they are 5 pin ISO (International Standard Organization) Micro Relays. From what I have read, the 85 and 86 pins are the CONSTANT CIRCUIT, while the 30 pin SWITCHES betwen the 87 and 87A pins, which completes the circuit.

Checking my resistance in the constant circuit (85 and 86 pins), I read infinity, and also checking the 30 and 87A pins I have infinity.

Does this mean the relays are good, or do I need to actually check the actual function of the switch by applying power to the CONSTANT CIRCUIT and then checking the SWITCH CIRCUIT??

If it is not my relays, where should I look next?

Thanks guys.

I have had great luck using a 9v battery between 85 and 86 while checking for continuity between 30 and 87. Use the continuity check feature on your DVOM with the tone feature (assuming yours has it) on 30 and 87 and touch the battery to 85 and 86. The tone should sound and the relay should click each time you touch the battery. This test will work with the battery + on 85 or - on 85 as long as you're not trying to check a diode suppressed relay (which I don't think you'll find on any of these Jeeps) It takes fourteen hands and some luck to hold it all, but it's really easy once you get the hang of it.

Thanks Shorty. So what your saying is, I can have resistance all day, but if the switch doesn't function within the relay, it's still no good.

si senor-- check out this that I just found:

http://www.autoshop101.com/trainmodules/relays/101.html

^second post over in Modified Tech^

lol, I'm the one that bumped it. I just wanted to make sure what you were saying (in laymean's terms) was what I was reading from that link right there.

Dozer11B said:

lol, I'm the one that bumped it. I just wanted to make sure what you were saying (in laymean's terms) was what I was reading from that link right there.

Click to expand...

AAh- never made it past the link when I thought "hey, someone was just asking about this-- how timely!"

LOL! Yeah I still apreciate you putting it in terms I can understand. The Army has taught me a lot of things, electrical theory and diagnosis not being one of them!

Thanks again!

Relays are good- thanks again Shorty.