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The reason to pull the relays and check them first is to make sure they actually work.
Then I checked the sockets, without the relays in them, to make sure they were receiving power.
I believe the test results I gave in the earlier post determine that the relays and sockets all work.
Now armed with that knowledge I will go ahead tomorrow and try to follow the trail of the wires for more testing.
As stated earlier fuse 8 works because the dome light and glove box lights were both on.
I popped a fuse yesterday and just swapped it out and tested both sockets again, without the relays in them, they do indeed output 12v. With the relays in I still have no central locking functionality though 😡.
I started another thread related to this central locking issue and also my gear shifter moving out of park without a key or foot on the brake because I think they might be related.
Here is the link to the new thread: gear shifter moves out of park no brake AND central locking not working
If an admin can lock this thread to avoid duplication and/or confusion that'd be great! Tx.
I started another thread related to this central locking issue and also my gear shifter moving out of park without a key or foot on the brake because I think they might be related.
Here is the link to the new thread: gear shifter moves out of park no brake AND central locking not working
If an admin can lock this thread to avoid duplication and/or confusion that'd be great! Tx.
I have an 89 740 GL with AT. It does not have a shift lock out as you can move the lever by just pushing the button and move it through the range of gears. It will only start in P or N and has been this way from new. If your central locking does not work after you worked on your blower then you need to re-check your work as you have moved something to cause the problem.
Yes jagtoes... I have been checking and re-checking everything with no luck and thus this thread.
"If your central locking does not work after you worked on your blower then you need to re-check your work as you have moved something to cause the problem."
so... that grey box at the top that the battery is attached to, thats the positive terminal, from which 90% of the things in the car get their power. red wire from there to the always-on fuses 6-7-8-9-10. green wire goes from fuse 8 to pins 86, 87 of both locking relays.
B,G,H,I are the locking motors (solenoids) in the passenger front door, both back doors, and the trunk, these are all wired in parallel together. relay D is unlock, relay E is lock. at rest, both relays connect both sides of the motors to ground (pin 87a of the relays)
when you lift up the drivers lock plunger, it grounds the 'unlock' relay pin 85, which fires the unlock relay, and connects the 'blue' wire to each lock motor/solenoid tto +12, this unlocks everything (remember, the other relay is still grounding).
when you push down the drivers lock plunger, it grounds the 'lock' relay pin 85, which fires the lock relay, and connects the yellow wires to all the motors to +12V, this locks everything.
the trunk key lock should do the same thing, turn it one way, everything unlocks, turn it the other way, everything locks.
unplug the two lock relays. connect a DVM in 'ohms' mode (or if it has a continuity beeper, even better) betwen one relay pin 85 and chassis ground. lift and depress the drviers door lock (note the door has to be closed for it to work. one way or the other, you should get 0 ohms or your continuity beeper should beep. now connect the meter to the other relay pin 85 and ground, do the same thing with the lock plunger, it should show 0 ohms or beep when you push/pull it the other way.
oh, here's a parts locator diagram to go with the above diagram...
I note nearly important goes through connector S (near the drivers end of the dashboard and T (inside the drivers door)
Great stuff here tx. It’s rainy all day where I am today so I will get to testing some things again tomorrow. Side note, I’m pretty sure from what I remember that my trunk lock was never working as part of the central locking system...
yeah, I realized looking closer at the diagrams, it was my 740s and 940s that had the trunk lock working the system, the 240's just had the drivers door.
so A and F in that wiring diagram are the drivers door manual lock plunger, and key lock respectively.
I'd find and verify that connector S, it should be at the left end of the dashboard, perhaps behind the side panel,,, if you unplug it, and on the dashboard side, jumper red to black or green to black, the lock should cycle up/down.
Yeah I’m thinking that S connector might be in the door panel. Even though that door panel hasn’t come off yet I’m sensing it will tomorrow... just to at least confirm some things.
In the picture I unplugged and am pointing at what I think is the S connector. I tried to jumper (using a paper clip to touch them together when it’s unplugged?) red to black and green to black with the driver door closed and I get nothing.
Okay this is solved. As you can see in the pic I had the wrong plug connected to the S connector. Once I found the correct one, I had it plugged in where the white relay goes, all the central locks worked again. Thanks for all of your help Pierce, the schematics and info you provided were priceless!
