Focus Fanatics Forum banner

Door locks

227 Views 8 Replies 2 Participants Last post by  amc49
I got a 2007 sedan, door lock/trunk switch fuse keeps blowing. (The one behind the panel) any ideas? I put a fuse in hit the button and it blows
1 - 9 of 9 Posts

· Registered
Joined
·
19,376 Posts
The cars have a very common problem with the wiring harness that runs into trunk lid, they fray the insulation to crack then it falls off to commonly short other wires or ground out to same. You have to cut away the outer covering to see the individual wires and do it where the harness flexes the most where it goes into lid hole as you raise and lower the trunk lid, that will point you to where to begin your search. You'll find bare/cracked wiring somewhere if so.

Which button you hit tells you likely what is messed up. The latch assemblies can do it too if the power to work them has to go way up due to old part with high resistance built up in it.
 

· Registered
Joined
·
19,376 Posts
Then look at latch assembly on that door. Pull cover and unplug the latch and then hit switch to see if blowing stops. Another way to tell is unlock and then while watching lock again, often the lock tab may seem to drag doing it and indication of lock mechanism needing grease.

The latches run dry of grease over time and then lock/unlock requires more force to overcome friction of parts rubbing dry inside latch. Can't lube them without taking latch apart (destructively, as they are made to not come apart).
 

· Registered
Joined
·
19,376 Posts
Just got to thinking. If ALL doors are locked the driver one is th unlocker for the others. You need to put all at unlocked and then lock and unlock each one using its' own button to find if the offender is say pass front, which I have had trouble with before. At handlocking the tight one may be your offender there too.,
 

· Registered
Joined
·
4 Posts
Discussion Starter · #6 ·
Fuse blew when I hit the passenger door lock to. But not when I hit the trunk button.

So when I hit either one of the unlock buttons the fuse blows but dont blow when I hit the trunk release

Also I'm testing it while the fuse panel is unbolted from the dash, would that make a difference?
 

· Registered
Joined
·
19,376 Posts
Nope, it is grounded by part of the wiring.

Keep going, the front pass side lock can be a master too, it masters the others and if a back is messed up it can show at pass button too. One keeps fiddling and blowing fuses until they are sure of which one is the bad one out of four.
 
1 - 9 of 9 Posts
Top