Power Door Locks - Loss of Power at Actuator

Hello -- I've installed an alarm with the intention of adding power locks/keyless entry on my 1990 Nissan Skyline. The wiring all went smooth until I added in the actuators for the power locks. The actuator doesn't seem to be strong enough to move the lock rods to lock/unlock the doors. At first, I figured the actuators were just weak and I'd need to look for something stronger (being that it's an older car, I figured there was just too much resistance in the rods). However I found that when testing the wires with a multimeter without the actuator hooked up, its flashing up to around ~10v when pressing lock or unlock (thinking it might be getting close to the full 12, but the multimeter isn't fast enough). When I hook up just one of the lock/unlock wires to the actuator I get the same thing. But, when I hook up both wires, and test, I'm getting around 2 or 3v on the multimeter when pressing lock/unlock. I'm also getting that reading for both the lock and unlock button on the SAME wire. Completely confused as to why this is --- or is this for some reason normal?

At this point, I'm unsure if the actuator is working fine and too weak, if the above is normal, OR if there's just something strange with the actuator and the wires to it. Again, the two wires work fine individually when tested, and each is fine when only one is hooked up to the actuator, but both cause a steep decline in reading. Any insight would be much appreciated. I'm by no means an electrical wizard or anything, this is just a hobby so please forgive me for my ignorance. Thanks!

Does the keyless entry module have relays built in for the door lock/unlock outputs? Sounds like they may be reverse polarity, but meant to operate a relay, which in turn connects to the actuator. Who makes the keyless module, instruction sheet perhaps?

So everything comes through the viper alarm system (3105v). From there, it connects to a universal 2 wire actuator. I'll search up to see if there are relays built in. I figured a relay wouldn't be needed since I'm getting the 12v at the connection, but am just losing that when the two wires (unlock/lock) from the alarm system are spliced into the two wires on the actuator. Again though, I don't fully understand how the actuator works, so that may be normal. I'l see if I can find anything on built in relays. Thanks for the reply

Pretty sure you'll need a pair of SPDT relays, or a DEI 451M.....https://www.the12volt.com/relays/relaydiagram4.html