MaxTheDog1

MaxTheDog1

Active Member
Full Member
Hi All,
It was quite cold here yesterday morning and I needed the full heater, rear screen, and heated mirrors on. The drivers mirror didn’t seem to be working. Having looked at the wiring diagrams in my Haynes and the documents I’ve managed to find online neither seem to have a switch for them. I assumed they were linked to the rear screen but can’t find any. Are they permanently on? Can someone confirm either way.
Regards,
Michael.
 
On a train, but had a full set of wiring with me. If it is a FL1 then they look to be on with ignition all the time. See attached. Screenshot_20231013_110807_Drive.jpg
 
Thanks Andy, that’s one on the diagrams I’ve got. Time for further investigation then to prove one way or the other. Just got rained off half way through washing it.😡 👍🏻
Cheers.
 
FL1 mirror heaters are on all the time the ignition is. On the FL2 they are temperature controlled but also come on with the headed rear screen.
I prefer the FL1 system, but it does shorten the life of the mirror heater pads on the back of the mirror glass.
 
Thanks Nodge.
Had a quick look this morning. This is what I understand from the wiring diagrams:
1. According to the fuse box cover, F3 supplies the mirror heaters and the rear washer.
2. Ignition switch position 2 puts a feed through F3.
Got the multimeter out, switched to ignition position 2 and got 76mA. Started up and it went to 96mA. Switched the rear wash on got 1.4A. By my calculations that’s a heater load of 1.15W or 0.576W (12V * 0.096A = 1.15W) each mirror. Seems very low.
I’ve got the same PDF diagrams that Andy has, and have only just noticed they show the heaters fed from F1 with a 2A rating for each mirror, whereas Haynes doesn’t give a Watts rating for mirror heaters. Checked F1 and there was no current until I washed the screen. So my FL is not wired as per the PDF’s, at least not F1 and F3.
If anyone can add anything Id be grateful but after this I’m going to assume they’ve failed but will wait till the frost before doing anything more.
Regards,
Michael.
 
What year? Up to 2002 F1 is mirror heaters. 2003 on is F3. The wonders of LR !! F1 then is the screen wash wipe which makes sense.
 
If you pop the tweeter off, the plug for the mirror is revealed. Brown green wire and the black next to it should give an ohms reading. Looks like pin 3 and 4 on plug.
 
Thanks Andy, will have a look tomorrow. From the figures I got earlier, I should get around 125 ohms resistance. 👍🏻
 
The mirror heaters warm the glass, as they are rated at about 5 Watts. Low current suggests corrosion of the power terminals on the heater pads.
 
Thanks to all who’ve replied.
Had the drivers door mirror off today and the lower bolt head sheared off due to it being rusted in!
Got the meter out and checked between all the pins:
5 way
Pins 1-2 = 72 ohm
1-3 = Open circuit
1-4 = Open circuit
1-5 = 111 Ohm

2-3 = Open circuit
2-4 = Open circuit
2-5 = 40 Ohm

3-4 =140 Ohm
3-5 = Open circuit

2 way (fold motor)
6.7 Ohm

So, given that the heater is between pins 3 & 4, that resistance equates to 83mA of current, which at 12 V equals just over 1 watt.
So as Nodge has said the 5W heaters should draw around 420mA each side, so together with the seized bolt it looks like there’s probably corrosion inside the mirror at the pad terminals.
Are they replaceable? British Parts have whole mirror units at £164 + VAT, AF don’t seem to list them.
When I checked the current yesterday at the fuse, I got 96mA. If the drivers door draws 83, the NS door is drawing 13mA so potentially is in even worse condition!
Cheers,
Michael.

IMG_2933.jpeg
 
MaxTheDog1 said:
Thanks to all who’ve replied.
Had the drivers door mirror off today and the lower bolt head sheared off due to it being rusted in!
Got the meter out and checked between all the pins:
5 way
Pins 1-2 = 72 ohm
1-3 = Open circuit
1-4 = Open circuit
1-5 = 111 Ohm

2-3 = Open circuit
2-4 = Open circuit
2-5 = 40 Ohm

3-4 =140 Ohm
3-5 = Open circuit

2 way (fold motor)
6.7 Ohm

So, given that the heater is between pins 3 & 4, that resistance equates to 83mA of current, which at 12 V equals just over 1 watt.
So as Nodge has said the 5W heaters should draw around 420mA each side, so together with the seized bolt it looks like there’s probably corrosion inside the mirror at the pad terminals.
Are they replaceable? British Parts have whole mirror units at £164 + VAT, AF don’t seem to list them.
When I checked the current yesterday at the fuse, I got 96mA. If the drivers door draws 83, the NS door is drawing 13mA so potentially is in even worse condition!
Cheers,
Michael.

View attachment 300119
Click to expand...
Hi, the heated mirror glass is available as a separate item. The genuine ones are upwards of £60 but pattern ones are easily available, ebay is where I got mine or one of the 'spares days' (one in Ripon yesterday) is always good for a bargain.
 
Thanks Andy.
Just done the track rod ends as a result of the MOT.
Also on the list the fuel tank cradle…..aaaarrgh.
 
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