Me too, me too. I bought an 02 F250 SC from my boss. I thought I had the door lock problem doped out, but I cut the Ford non-oem remote start/keyless out of the loop and traced the wiring back to a plug where the keyless system was in parallel. The switch has .7 volts open and 12.7 closed, I did not test the acctuators because all four would have to of died all at once. Along with the locks, the dome light does not work on the door switch. I am beginning to think BCM, I'm going to buy a helms manual, but does anyone have a similar experince and solution?

I forgot to mention about the door ajar light is lit with the ignition on while the dome light only works with the int light switch.

 

So, in reading this thread, there is definately some good info here. My symptoms, when trying to use the armrest switch to lock or unlock my doors, the relay fires and the actuators 'try' to move, but they just don't, and it is all four doing this. I can't see all four actuators going at the same time. I used a v-meter at the actuator plug and am getting a good 12.5 volts (ignition off) when the switch is pushed.

Am I correct in assuming if the relays were bad then they either wouldn't fire or would send very poor voltage to the actuators? If so, then what the heck is my trucks problem??? It is a 99 PSD (crew).

I pulled the relays and reseated them just to be sure. But then I noticed something odd. Above someone mentioned there are three relays, well, the relay block in my truck has three larger relays and two more spots for the smaller, half size relays, of which only one is present. So can someone give a break down of what those 4 relays do and what the 5th empty spot is for?

I am really confused and am ready to just take this sucker into the dealer. :-(

 

I would start with doing what gotama did. The actuators are weak to begin with, but if you keep the linkage and the lock and tumbler clean and lubed, they work fine. I use a combo of silicone in the summer and if needed, lithium in the winter. It has kept my 2001 locks working great.

Austin

 

and they are still workin great!...kiss works for me!

 

I've got one actuator that is not working, it just wiggles when using the door switches. I figure I need to troubleshoot the actuator. Here's a little electronics theory for those it might help (this is what I do for a living and not at radio shack!). For the actuator to work, it must have a good voltage (anywhere around +12 should do) AND a good ground. On relay coils and actuators, it's the current through them that does the work. The key to good T/S'ing is knowing if the supply voltage or the ground controls the item under test. If the ground circuit is open, you'll read your supply voltage (+12V) anywhere before the wire break/open (even on the negative side of the actuator). If the supply voltage is noticeably below your battery voltage, then it's time to look at bad contacts earlier in the circuit path (i.e. relays, switches, etc.). You might think the item under test is shorted (with the lower voltage reading) when it's actually a weak relay contact and this has happened to me several times on cars. With automobiles, The readings should be 12V or 0V (ground). Anywhere between those two numbers and that part should be looked at closer.

 

THanks for the info roaky81, very useful. In my case it's not just one actuator, it's all four which suggests one of two problems which would affect all four at the same time, bad relays or bad ground. On that note, anybody know where the ground is for that circuit??? My local Ford shop will charge $90 just to diagnose the problem.

Has anybody had to replace their relays? If so, about how much were they? I don't mean the actuators, I mean the realys on the firewall behind the radio.

Cheers!
:-)

 

The relays cost about $10 each retail.