I have problem because I have tension on the fuse No. 50, but after I turn on heating the rear window on the plug at the mirror I do not have tension on heating wire. Is there somewhere still some fuse or switch?
I'm not sure how you're using the word "tension" here. Tension usually refers to mechanical force between 2 objects like if a weight was hanging on rope- then the rope would have tension on it. It can also be used to describe emotional problems between people- like my wife lost the rent money at the casino so we are experiencing some tension at home.
For electricity there are 2 terms that are applicable here: continuity and voltage. Electrical continuity refers to how all electrical circuits must be in a complete circle from positive to negative through a resistor in the simplest form. Fuses, for example, should show continuity on a tester through the 2 sides of the fuse. That's how you test fuses to be sure that a fuse is good in case the fuse is damaged in a way that you can't easily see the break in the element.
Voltage or power is measured at the device, but can be misleading sometimes. For example, if you remove a fuse and test for power at the fuse socket- you'll always find that on one side of the fuse socket. The other side, where you do not find power to earth with a tester, is the side that goes to something like your heated mirror switch.
I would assume there is a relay of some sorts either under the hood or under the dash for the heated mirrors. When I've tested things that have broken on cars in the past I generally find the problem to be the switches. That's the first thing I'd test. If the switch has 2 connection points, then put your tester on those 2 points, activate the switch, and look for continuity at the switch. If you don't find it- then you've got a bad switch, and you don't even have to search for the relay or a wiring diagram.
Pin 4 & 5 yes, you are sure you have voltage to the rear window, do you have the problem on both sides? Thre is no more switches involved , it gets pwr from the rear window defrost relay then to the 7,5a fuse, then to a connector on the A pillar, from there its split into left & right side, I assume the movement of the mirrors work...
Reference: 2004 Ford Publication: Focus Wiring Diagrams. USA market
Right mirror: pin 4, Green/Orange .35mm goes to Rear Window Defrost
Right mirror: pin 5 Black .35mm, goes to Rear Window defrost
Left mirror: pin 4 Green/Black .35 mm goes to rear window defrost
Left mirror pin 5 Black .35mm goes to Rear Window Defrost
All these Black wires go to ground
The other two wires are joined together to a Green/Blue .35mm wire that then goes to a 7.5 Amp fuse labeled F2.50. Fuse box inside the car by driver, labeled "Power Mirrors"
While the heated mirrors turn on when you turn on the rear window defroster, the defroster is on another circuit[fuse]
It would seem to me that the mirror heater wires do NOT go back to the rear. [But I could be wrong]
Continuing on with the circuit description:
The fuse previously mentioned is connected to the fuse for the rear window defroster which is fuse F2.49 25 Amp
These two fuses go to the Rear Window Defrost Relay contact which is labeled C2021 this is also in the same fuse box
The other contact goes to fuse F1.7 40 Amp in the engine compartment
get a voltmeter:
is there ~12volts on fuse F1.7?
is there voltage on fuses F2.49 and F2.50, while turning the rear defroster on and off? [You want to see the voltage go on/off in sync with the defroster switch]
Maybe the heater element burned out on only one mirror
Does your rear defroster work?
I see you have a 5 door car
There are tremendous problems with the umbilical goes to the rear hatch. the wires inside will cracked, short, break apart . All INSIDE the umbilical
If you are still stumped [cannot figure this out] then send me a PM with your real Email address and I will send you scans of my Ford Wiring manual. Understand it is 20 mm thick So I will only send you concerning this circuit
In the fuses that I have seen there are bare spots on both sides of the fuses so be sure to measure both sides of the fuse
rear defrost work's ok, but i don't have voltage on both side mirrors. Now i need go to sleep ( just got back from night shift at work) i hope that the weather will be ok, so i will use voltmeter and look at the read window wire ( mayby ground from mirrors somewhere is broken)
and i have 3 door version
Ok, i have voltage on fuse f2.49 and f2.50, but I took out the fuse went out fuse f1.40 Interior lamps switch off.