Power Lock Issues/Relay

[TheIntruder]

Howdy,

Trying to track down a power lock issue with my '94 LX -- they'll unlock, but don't lock in response to the driver's door lock.

Found an old thread with the opposite situation, which was apparently solved by a new relay.

I've gone so far as to test the door switch at the connector, and that seems to indicate the switch is fine.

I can hear the relay clicking while manipulating the driver's door lock, so it hasn't failed entirely, but it would still seem to be the logical suspect.

But, based on what I see in the service manual, versus what I see when I search for the part, I'm uncertain which is the correct part.

The service manual illustrations show a different, more complex plug, while this part is what comes up in searches, and on Rockauto's catalog.

Based on what I can see when I poke around under the dash, it is indeed the correct part, even though it doesn't conform to the service manual's drawings.

If I were to label the attached pic of the relays (from L to R):

1) black/white higher position
2) black/white
3) larger black
4) larger grey

Which one in the llneup is the suspect?

Looking for the wisdom and confirmation I'm not crazy.

A new twist emerged during this testing, being that the RR door lock has stopped actuating altogether, and is doesn't freely lock/unlock even manually. I'm wondering if the actuator died coincidentally, or something is binding up. Ugh.

Thanks for any guidance.

[me109]

The RR lock may have been gummed up with door seal. That stuff was nasty when it was new, and it doesn't age gracefully.

Unfortunately, I don't remember which relay is what, and no longer have a BG with power locks... Sorry.

[SgtFox]

If I remember correctly, the plastic casting of the relay says Door Lock Relay on it.



So, relay connector is K-10, which should have:
Blank, Green, Green/Orange, Black
Blank, Red, Green/Red, White/Green
in a 2x4 pin connector.




If the relay tests bad, you can open it up and clean the contacts inside. They may be carboned up.

If you disconnect the relay and get a DMM on DC voltage mode, you should see:

Driver door locked:
Green/Red should have 12V, with other lead of DMM on chassis ground.
Green/Orange should have 0V

Driver door unlocked locked:
Green/Red should have 0V, with other lead of DMM on chassis ground.
Green/Orange should have 12V

At all times, White/Green should have 12V

With the DMM in continuity mode, or resistance mode, measure from Black to chassis ground. You should have continuity.

If you plug the relay back in, you should be able to probe the Green and Red wires, by pushing the leads into the back of the connector. Back in DC volt mode, you should have +12V with the door lock in one position and -12V in the other (without moving the test leads) The relay essentially swaps from +12V on Green, 0V on Red to 0V on Green, +12V on Red.

[1st Gen]

Yea, clean that black glue stuff off the mechanism and try again.

[TheIntruder]

Thanks guys. I guess I'll have to dig around underneath, and maybe pull the trim panel to make that easier. Of course, it would have have to be the one buried in the corner.

I'm quite familiar with the black stuff -- it's proper name is butyl tape. It will resist everything but a solvent, like a thinner, or spirits. I use acetone, which isn't quite as harsh (and commonly used around skin as nail polish remover) but still effective. But once it gets on clothes, it's mostly over.

[FE3-323]

any update?