Power door lock issue

[rwljpl]

Here is the situation:
My truck had factory power door locks. They have never worked since I have had the truck. Since I was taking the doors apart to fix other things, I figured I’d look into the power door locks as well. Turns out, there was no actuator at all on the driver side and the actuator was bolted in but not plugged in on the passenger side.
I hooked up brand new actuators without bolting them in just to test the system. I also wired in new switches.

Nothing happened when I tried to lock and unlock doors, so I replaced the power lock relay under the dash. Now it clicks when I press up or down, but the actuators still aren’t moving as they should. I figured maybe it’s a bad wire with too low voltage. This is where it gets odd.

I hook up my voltmeter to the harness that the actuators plug into. When the switch is not being pressed up or down, I get 12 volts. If press the lock switch up nothing happens. If I press the lock switch down the voltmeter goes to zero. It’s like the system is pushing the lock up when it should be in neutral. It’s like it’s stuck in the up position at all times.

When I plugged the actuator into the harness it was in the down position but as soon as it was plugged in, it pushed the actuator to the “up” position.

What could be causing this? I’m sure the truck has been rewired - that’s obvious. But I am no electrician - I know just enough to be dangerous. Is there an easy fix? Is it possible there is a second relay for the power door locks that could be causing it to be powering the locks into the up position at all times? The relay I changed was black rectangular 3 pronged.

https://shop.advanceautoparts.com/p.../20975713-P?searchTerm=Power door lock relay#

Can you buy a power lock kit that uses factory door switches but bypasses the factory relays (kind of like the LMC kit for the power windows)?

Thanks

 

[Snoots]

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[rwljpl]

Thanks
Unfortunately I am not great at reading wiring diagrams
If it helps, I have the same issue on both sides - so whatever it is that is sending out power to push the actuators up at all times, it is a “centrally” located issue
I’m guessing it has to do with the relay or the way the wires are tied into the relay
If the tan and gray wires were switched where they come into the relay itself, would that cause the issue I am seeing?

 

[rwljpl]

I pulled out the power door lock relay housing to see if the wires on the diagram above match what is on my truck
The wires do not have much slack so it is hard to get a good look at everything
But it appears that I have 2 orange wires, a green wire, and a black wire going into the power door lock relay
That does not match the diagram above obviously
Does anyone know what the round flasher/relay right next to the power door lock relay does? And what about the much larger rectangular thing? Is that also a relay? What is it for?

See the picture - These appear to be the wires going into the back of the power door lock relay

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[rwljpl]

This may be a better picture

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[Matt69olds]

That’s the horn relay. The power door lock relay is mounted behind the dash, up above the emergency brake pedal. It’s a square metal relay

 

[eskimomann209]

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Pulled this off the google. This is what the relay looks like.

 

[rwljpl]

Ok, then I’ve been looking at the wrong relay
Where exactly is it located? I can hear it click but I cannot see a relay like that up under the dash

 

[Matt69olds]

Since you can hear it click, you know the wiring from the door switches, courtesy lamp fuse, etc are good. Make sure the power accessory circuit breaker is installed. It’s on the lower right corner of the fuse box. That circuit breaker and related wiring is what actually supplies the power to cycle the actuators.

The power door lock relay is mounted behind the dash, very close to where the headlight switch is. Your probably going to have to lay down on the floorboard and look up begging the headlight switch to actually see it.

 

[rwljpl]

Ok, I found the power door lock relay
Before doing anything else, If like to try a replacement
But no one seems to carry this relay anymore
It’s RY-547
Any ideas where to get one that won’t cost a fortune?

 

[eskimomann209]

This ones pretty reasonable

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[Camar068]

They aren't cheap for what they are. I ordered one off ebay and it came from India. Think mine was for a buick car, but the connections were the same. If you go this route you'll need to bend the bracket (which is ground [negative for relay]) to fit or run a ground wire to the mounting tab.

verify connections before ordering please.

https://www.gmsquarebody.com/threads/door-lock-relay.31717/

 

[Matt69olds]

Before spending money on a new one, make sure it’s actually defective. See if you have power on the orange/black wire. If so, apply power and ground to the tan and gray wires. One way should lock the doors, reversing the power/ground should unlock.

If that works, you can be reasonably sure the relay is bad. Before spending money on a replacement, carefully pry up the tabs that hold the cover on. You might be able to clean the relay contacts and get it working again.

 

[TPISly-C10]

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Pulled this off the google. This is what the relay looks like.

this one was close by the gaz pedal on a 1989 Suburban!

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[rwljpl]

Eskimomann209, are you putting that relay up for sale? Does it work?

TPISly-c10, yes, that’s it - mine was close to the gas pedal too, up by the steering column, obscured by insulation. It is not easy to get to. It was behind and above another panel that hold relays for horn, etc., plus what I think is the cruise control module.