Autodimming mirror - advice on best setting please?

[joebongo]

I have wired up an autodimming mirror to my E38, and I'd like some opinions on the following choice I need to make:

1. Have the autodim function on all the time the car is in use.
2. Have the autodim function work only when the lights are switched on.

I've got to choice 2 at the moment, but could get 1 I think if I splice a different wire tomorrow.

Which do you think would be best and why?

I can't recall dipping my mirror in the daytime ever so does autodim ever come into play when driving in daylight?

Cheers,

Joe

[joebongo]

Bump, a la mumsnet stylee.

[Morningside]

Autodim at night only for following cars.

Some models can 'detect' following car headlights via photodiode or LDR and autodim. (Photochromic?). Does yours have this?

[joebongo]

Yes it's an electrochromic/photochromic one.

I have the choice but wonder is there anything to be gained by having it ready to dim and ready to react to lights in the time I don't have my lights on?

Tunnels, LED lights on 4x4's, lorries etc. Is it worth having ready to dim all the time?

Need to get to bed now as our 3 month old will no doubt wake us up soon. Will check in the morning for the PH words of wisdom.

[ivaylo]

They usually have two sensors, one at the front and one at the back. They only dim when there is a difference between the sensor data. I suspect the system is switched on all the time but I haven't verified this.

[GPT]

Mine disables autodim when I select reverse, I can't say I've ever noticed it dim in daylight before though. Make of that what you will.

[joebongo]

If I was a bit more techy I would need to run a wire down the A-pillar and into the LCM to do the reverse cut-off, but I noticed it takes a good 20 seconds to completely go back to clear by which time I've usually done my reversing so I'm not too bothered about that bit.

[dome]

If its anything like my e34s then the sensor is built into the mirror. Mine comes on with the headlight and I think goes off when you select reverse. Simple enough to wire in I'd think. There's a chance the wiring may be there for it already...

[joebongo]

Yeah, I've even had an endoscope all round the headliner area - I must be the only E38 owner without it prewired!

I've got it soldered in now to activate/be ready to dim with the light switch which will do. My mirror is as you say and I'm glad it's done. I'd like to say it adds value to the car but I'm not sure it adds much! Not bad for a tenner and a few old PC wires though!

[dome]

Mine is bloody noisy though but It's 20 years old so I forgive the car its little foibles

[joebongo]

Your mirror or the car? Your garage looks like two nice rides there, I'd forgive quite a lot with those two!

[fangio]

I like mine on during the day if it's sunny, it cuts out glare and soothes the eyes.