Hi,

Thought I'd ask for some help.

I too have a power lock problem, but mine is manifested differently than others that I've read about on this forum. Mine is failing intermittently, and when it does, it always fails the same way.

2000 F-150 XLT SC 4x4
Symptoms:

Drivers side and passenger switch lock does not work.

Drivers side switch unlock does not work.

Passenger side switch unlock does work - both actuators unlock.

Alarm keyfob (aftermarket alarm) lock does not work.

Alarm keyfob unlock does work - both actuators unlock.

When working normally, the actuators are not sluggish - Pop right up and down with no hesitation.

When in the failing mode (as described above ) the actuators don't seem to be energized at all on lock, and pop up without hesitation on unlock.

Any thoughts on where to begin??

Many thanks,

Dennis

 

Just a thought. there's a bundle of wires going into the door that can chaffe against the inside of the door skin. See my later entries in the "my blinker fluif must be low" string.

ricochet

 

Thanks. I'll check that out.

Dennis

 

I am guessing that you did NOT have a factory supplied keyless entry system, prior to having the aftermarket alarm installed. This tells me that the installer interfaced with your door lock circuit using the "5-wire" method. This is more than just tapping into the circuit, as it involves separating the wire, and installing a relay into both the lock and unlock sides of the circuit. 99% sure that there is a bad connection here, where the interface to the lock circuit was made. Bad connection, or possibly a bad relay. Likely a bad connection, as relays don't normally fail in this application, and if they do, I have never seen one fail intermittent, either go or nogo. Take it to the installer. Any installer worth his salt should not charge you for this warranty repair. (I give lifetime coverage on installation integrity)

Matt

 

Right you are Matt. I had the aftermarket alarm installed just a couple weeks after I bought the truck new, so it's been 5 years. It's worked fine up till now. I had the alarm installed at the dealership, which has since changed hands, and the original installer is gone, so I think I'm on my own on this one. Thanks for the idea, though. Tomorrow, I'm going to check out the alarm connections and see if I find anything.

Regards,

Dennis

 

well here are a few places to check...I have the exact same truck you do, and I caught the wires in the passanger kick panel, just above the fuel pump inertia switch (the one that kills power to the pump in an accident...). BUT, some people catch them high on the drivers firewall, forward of the parking brake mechanism. It depends where they caught the circuit...passenger side is easier to check, just pull the sill plate, then the kick panel. If there are ANY wires that don't look factory here, they will be the lock/unlock interface.

Look for them to be hooked into:
pink/yellow (lock)
pink/green (unlock)

give them a slight tug, and see if one is loose, or comes apart, (at either end, the factory wire conn, or the relay...)

report back!!

Matt

 

Thanks Matt

You were right. On my truck they tapped into the circuit on the drivers side way up high. (What a pain to get to.. sheesh) Anyway, I checked all of the connections. None seemed particularly loose, but I unplugged and reseated them anyway. (The installer used plug in connectors) I also reseated the plug at the alarm module.

The locks now work fine again. I'm optimistic, because over the last few days the problem had gone from intermittent to pretty solid.

Interestingly enough, the relays are actually inside the alarm module, and are hard soldered to the PCB in the alarm. If one of those is actually going bad, I'll need to replace the alarm.

Thanks for the help,

Dennis

 

Good!! sounds like you got it...

relays don't generally fail like that (intermittant), so it was most likely a loose connecter.

That location IS a pain to get to. It's a tossup on where to catch them, major pain on the D side vs. slightly less of a pain on the pass side + running wires back over to the D side.

Hope they stay fixed for ya!



Matt

 

I've had a similar problem, but it seems like both the door switches and remote are working. The locks "try" to move, but don't move all the way. I hit unlock and the **** bumps a little, but doesn't unlock. This has been happening sporadically with either locking or unlocking, door switch or remote. It also seems like if I keep playing with the locks they get weaker and weaker. If I trigger the switch over and over, the locks usually work for the first couple cycles, and then gradually stop.

I was leaning towards a short somewhere, but after hearing about the aftermarket set-up...

I installed a remote start and tied it into my locks. I'll give that a looksie first. I'm glad I checked here to see if others were having the same problem.

 

Crownie-
You have the classic symptoms of failing actuators, our trucks are known for it. (Ford has actually updated the part...)

Try this link to a search for more info...

Failing actuators, power door locks

I have already had to change both of mine.

Matt

 

I have the symptoms Crownie mentioned. You said it sounded like a actuators are going bad? That's what I think. My remote is all factory and no alarm. I've checked everything and can't find anything wrong, so I'm guessing it the actuators, too. The link you provided doesn't work (maybe it did? This hasn't been posted on in a while). How do you remove the actuators? I tried, and after about an hour I gave up. Thanks!