Ok, I know there are a few of these but here we go... 2003 super duty f250 6.0 crew cab! Fuses are good, door switches are good, vsm is good (have a 2nd identical truck & swapped,
working truck is fine with problematic truck vsm & still no lock with known good vsm), new actuator in front drivers side door (verified old was good after I swapped) I hear relay in vsm click when pressing lock/unlock but that's all I get! Got 14hrs chasing wires & checking continuity & voltage with no luck on finding a problem, even compared multimeter findings from 1 truck to the other cause I'm not real familiar with the cluster of wires in these things & compared to line voltage or high voltage, I've realized you've got to throw logic & common sense out the window! Is it possible 1 bad actuator could cause whole power lock system to fail?

PLEASE ANY HELP WOULD BE APPRECIATED!!

 

Anybody? Getting frustrated & desperate.. Please?

 

im interested in this too as i just replaced all 4 of mine worked well till i did the engine swap then quit it did lock on its own once Evan the remote wont make them work so following this

 

I ended up figuring it out last night! I knew I had a "door ajar" ground short that the dealer had "fixed" by running a ground to the problematic door (not fixed but band aided)! But while trying to figure out locks, I realized the "door ajar" problem seemed likely in harness that ran from driver side to passenger side, under front seats! So I thought I'd program a fob to see if I'd get any different results because door switches only toggled relay in VSM. Well sure as ****, fob made 3 actuators buzz slightly when unlock was pressed but nothing when lock was pressed. Front passenger door made no noise at all! So now directing attention to front passenger door & after a short while with multimeter I found myself back at harness from drivers side to passenger side under front seats! Removed front seats last night to find all kinds of wire damage! It appears a rat was in there for a period while the truck sat at my sisters inoperable due to blown head gasket! I'm amazed VSM, no blown fuses or any other issues or damage was caused considering int. light, door ajar trigger, passenger door lock (+) had been completely chewed in half & 4 other wires had large portions of copper exposed! All working good now! Guess my point is, all the information on the net such as "actuator fix", "broken wires in boot" etc. is very helpful... But every problem could be completely unexpected or unrelated to "others" similar problems! Do you have a fob programmed (that's what pushed me in right direction)? If fuses 5amp(#19) 15amp(#17) 30amp(#7) 30amp(#102), door switches (driver & passenger) & VSM are good Use multimeter & check for continuity, check for (+) & (-) power @ actuators when pressing lock/unlock! Any questions or help I can give, glad to do so!