Door Locks Stopped Working

[G_RIDE_81]

Hello all. I am pulling out my old alarm replacing with a newer one in my '81 Chevy MC. I was swapping wire for wire but am wiring from scratch the alarm's relay module to power the factory power door locks as installer of the old alarm got this wrong way back and they never worked. I never installed electronics that are sensitive to + and - power sources before so I used a fancy LED test light to help me out. While probing for the correct wires (which I did tap into at the passenger kick panel; light blue and black wires) I must have probed the wrong one "killed" something. The locks no longer open via the door switch(es). The alarm's module does trigger the MC's relay and pops the locks, though! Flipping the door switch makes the relay click but actuators are a no go.

Any ideas on what could have gone wrong? I had just replaced the door switches with new Dorman's a couple months ago plus they're just copper contacts so I don't think they are the problem. What about the ACC/Pwr circuit breaker on the fuse block? How would I test it? Could it be something else?

Thanks in advance!

 

[fleming442]

An LED tester won't pop the circuit, unless you short something.
Here's a fun fact: the door locks won't work unless the relay housing is grounded.

 

[pontiacgp]

which brand of alarm are you installing?

 

[88AZSS]

I have a similar issue where my door locks work intermittently. Good ground to the relay, actuators work when bench tested to a power source. I've narrowed it down to a pinched wire somewhere or just bad switches. It very possible that the switches are bad right out of the box. Copper contacts or not, if it isnt right, it isnt right. Do you have a known working switch that you can test with?

 

[G_RIDE_81]

An LED tester won't pop the circuit, unless you short something.
Here's a fun fact: the door locks won't work unless the relay housing is grounded.

Re: tester, that's exactly what I understood. So, I obviously shorted something but what? It has to be something other than the relay and switch.

And yeah, as mentioned the system worked fine for decades until I started probing around.

 

[G_RIDE_81]

which brand of alarm are you installing?

A Viper 5706v with 451m door lock module.

 

[G_RIDE_81]

I have a similar issue where my door locks work intermittently. Good ground to the relay, actuators work when bench tested to a power source. I've narrowed it down to a pinched wire somewhere or just bad switches. It very possible that the switches are bad right out of the box. Copper contacts or not, if it isnt right, it isnt right. Do you have a known working switch that you can test with?

I do have the previous switch. Haven't tested since I had the issue. Will test it... soon as I find where I stored it!

 

[G_RIDE_81]

Well, I tracked down the circuit breaker at local parts store for $4.99, cheap enough to trial/error. It worked!! I also put the original back in and it worked as well. It reset apparently. Who knew, live and learn!

Thanks everyone for the assistance and hope this helps others in the future!

 

[fleming442]

Huh. I thought locks were fused, and the breakers were for seats and windows....

 

[Max Headroom]

Huh. I thought locks were fused, and the breakers were for seats and windows....

I have had cars with them both ways. If memory serves, option packages made a difference which way the went.