On Board Computer (OBC)
09-25-2005, 06:04 AM
#1
Track Day
Thread Starter
Join Date: Jun 2005
Location: Northern Ireland
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
On Board Computer (OBC)
Just a small worry this one...
When you put the sidelights or headlights on, the OBC dims itself slightly from the normal daylight brightness. When in 'dim' mode, the illumination of it flickers slightly.
If I brighten up the dashlights the flickering ceases, but on a mid-range and dimmer setting of the instrument lighting, it flickers.
It is not in sympathy with engine or alternator speed as it does it even when the engine is not running.
Doesn't really worry me - yet. More idle curiousity... Any theories?
When you put the sidelights or headlights on, the OBC dims itself slightly from the normal daylight brightness. When in 'dim' mode, the illumination of it flickers slightly.
If I brighten up the dashlights the flickering ceases, but on a mid-range and dimmer setting of the instrument lighting, it flickers.
It is not in sympathy with engine or alternator speed as it does it even when the engine is not running.
Doesn't really worry me - yet. More idle curiousity... Any theories?
09-25-2005, 11:53 AM
#3
Burning Brakes
Join Date: Mar 2005
Posts: 909
Likes: 0
Received 0 Likes
on
0 Posts
I think it varies the dimness by a simple potentiometer (the turn **** for dimming). These can have 2 modes of operation and 1 can work without the other. The two modes being partial resistance and closed circuit. Closed circuit would be the full brightness and partial being anything from off to full. My first thought would be to pull this switch and clean it out. Or if its just a couple bucks replace it. I'm not familiar with how the contacts work in it, but you could perhaps file them for a short lived solution. Could be the spring holding pressure between the contactsis old and needs to be rebent or replaced.
Anyway, I'd start at that pot first.
Anyway, I'd start at that pot first.
09-26-2005, 06:56 AM
#4
Track Day
Thread Starter
Join Date: Jun 2005
Location: Northern Ireland
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Yes, I think the dimmer potentiometer might be the issue. However I think you might see other lights flickering too if this was the case, which I can't see.
One other effect, when you go to full dim the OBC brightens up a bit just at the last part of the potentiometer track.
I wonder if the dimmimg occurs when the OBC is doing 'stuff' i.e. it must recalculate all the averages, and the current speed and fuel consumption, and I guess it does this in some sort of loop of code. Maybe reading the values increases the current draw momentarily and causes the light to dim. I will try and watch for a regular pattern of flickering.
One other effect, when you go to full dim the OBC brightens up a bit just at the last part of the potentiometer track.
I wonder if the dimmimg occurs when the OBC is doing 'stuff' i.e. it must recalculate all the averages, and the current speed and fuel consumption, and I guess it does this in some sort of loop of code. Maybe reading the values increases the current draw momentarily and causes the light to dim. I will try and watch for a regular pattern of flickering.