I am not sure why it comes on all the time.. I already know how its supposed to come on every time the car is started.. but usually when i press the brakes it goes away..
I had a brake and a reverse light out.. So I replaced the bulbs with some out of the pile of bulbs I have (All taken from E28's) and the lights now work but the warning light "check" telling me to look at the cluster above my rearview mirror are still on..
So my real questions are:
What bulbs go where? There is small and big ones..
And does it matter?
Also does it matter if the bulbs are not the EXACT same bulbs?
Any other similar problems that anybodys had?
Brake light warning above rearview mirror always lit!!
Brake light warning above rearview mirror always lit!!
Last edited by Manny D. on Jan 26, 2008 9:30 PM, edited 1 time in total.
I've found that if there is a difference in resistance in the circuit, it will trip the light. This usually happens with one bulb coming on before the other. Also, once the light comes on, it will always stay on until the car is completely shut off, restarted and the test (pushing the brake pedal) completed again.
It doesn't much matter what bulb is where (small globed ones are supposed to be in the lower, outside corner of the assembly), but it does matter that each circuit has two of the exact bulbs on it - otherwise, it will trip the check panel.
Also, remember to only use Tin (Sn) based bulbs. Somehow, the check system doesn't like others such as brass-based bulbs. I have a stash of them from salvage yards.
It doesn't much matter what bulb is where (small globed ones are supposed to be in the lower, outside corner of the assembly), but it does matter that each circuit has two of the exact bulbs on it - otherwise, it will trip the check panel.
Also, remember to only use Tin (Sn) based bulbs. Somehow, the check system doesn't like others such as brass-based bulbs. I have a stash of them from salvage yards.
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MisterFixit
- Posts: 1020
- Joined: Jul 21, 2006
- Location: Golden, Colorado
Lights - size DOES matter ...
I gotta add my opinion here.
Stock bulbs come in two flavors, bright (big) , and dim (small), for the following functions:
Bright: turn signal, reverse, and brake lights. The brake is the outer-most section of the three red parts on the bottom half.
Dim: tail (running, parking) light, the middle section of the red parts.
Euro cars had a rear fog in the inner-most red section, but not the US models. More on this later...
YES, it does matter which bulb goes where, and if you want to have working lights next year, DO NOT mix them up. Reason- if you put the bright (21 watt) bulb in the tail light socket, where 5-10 watts are expected, you WILL get some melting and have problems. I have seen it, and had to use a hack saw to solve it. The larger bulb will 'fit' in the socket, and will 'work' (ie, comes on), but is way too hot under continuous use for the tail light assembly. See, BMW put vent holes in the reflectors around the brake (and rear fog) lamps, but not around the tail light. All that heat builds up, and presto, melto, there goes your plastic.
NO, you do not need the EXACT same bulb, but it must have a nickel plated base, NOT a brass base. Corrosion issues will drive you mad. Try to observe the wattage and brightness numbers to get them to work correctly. "P25-1, 32cp" is the brighter bulb, 32 candlepower. "R19/5, 4cp" is the dimmer bulb, smaller and shorter, with 4 candlepower. These codes are stamped into the wiring traces next to the sockets for the various bulbs.
OTHER: Yes, there are several places you can have trouble, such as the areas where the bulb holder makes contact with the metal traces (where the power comes from), and inside the bulb holder itself (the whitish nylon thing) where the bulb and socket make electrical contact. And the weird 'Check Brake Lights' warning is a common gremlin, it happens when the light control module is unhappy. This seems to be random, and could be double-checked by having someone visually confirm the light functions. You may be able to solve it by cleaning up the contacts with extra fine (600 or finer) sandpaper, then using 'electrical grease' to keep the corrosion from returning. Sometimes just fiddling / twisting the bulb holder slightly to get fresh contact makes a difference.
ALSO: note the difference between the two styles of bulb holder- one for all the bulbs EXCEPT the tail light, and one for the tail light. They are not interchangeable.
PM ME directly, as there are some easy improvements to the design of these lights, and would be happy to share the details with you. You can employ the rear fog light section to add tail and/or brake light functions, plus brighter bulbs, and make the car much easier to see. Also you can eliminate the single point failure potential designed into these lights.
See http://www.mye28.com/viewtopic.php?t=23526 for some discussion. (Shameless commercialism, with a dash of altruism).
As a general rule, whenever I hit the brakes hard, I look in the mirror to see if I need to find an escape route, just in case the meatball behind me isn't fitted with a working brain. I'd rather wind up in a ditch voluntarily (under some degree of control) than be crushed by some 'citizen' in a Fraud Exterminator.
Stock bulbs come in two flavors, bright (big) , and dim (small), for the following functions:
Bright: turn signal, reverse, and brake lights. The brake is the outer-most section of the three red parts on the bottom half.
Dim: tail (running, parking) light, the middle section of the red parts.
Euro cars had a rear fog in the inner-most red section, but not the US models. More on this later...
YES, it does matter which bulb goes where, and if you want to have working lights next year, DO NOT mix them up. Reason- if you put the bright (21 watt) bulb in the tail light socket, where 5-10 watts are expected, you WILL get some melting and have problems. I have seen it, and had to use a hack saw to solve it. The larger bulb will 'fit' in the socket, and will 'work' (ie, comes on), but is way too hot under continuous use for the tail light assembly. See, BMW put vent holes in the reflectors around the brake (and rear fog) lamps, but not around the tail light. All that heat builds up, and presto, melto, there goes your plastic.
NO, you do not need the EXACT same bulb, but it must have a nickel plated base, NOT a brass base. Corrosion issues will drive you mad. Try to observe the wattage and brightness numbers to get them to work correctly. "P25-1, 32cp" is the brighter bulb, 32 candlepower. "R19/5, 4cp" is the dimmer bulb, smaller and shorter, with 4 candlepower. These codes are stamped into the wiring traces next to the sockets for the various bulbs.
OTHER: Yes, there are several places you can have trouble, such as the areas where the bulb holder makes contact with the metal traces (where the power comes from), and inside the bulb holder itself (the whitish nylon thing) where the bulb and socket make electrical contact. And the weird 'Check Brake Lights' warning is a common gremlin, it happens when the light control module is unhappy. This seems to be random, and could be double-checked by having someone visually confirm the light functions. You may be able to solve it by cleaning up the contacts with extra fine (600 or finer) sandpaper, then using 'electrical grease' to keep the corrosion from returning. Sometimes just fiddling / twisting the bulb holder slightly to get fresh contact makes a difference.
ALSO: note the difference between the two styles of bulb holder- one for all the bulbs EXCEPT the tail light, and one for the tail light. They are not interchangeable.
PM ME directly, as there are some easy improvements to the design of these lights, and would be happy to share the details with you. You can employ the rear fog light section to add tail and/or brake light functions, plus brighter bulbs, and make the car much easier to see. Also you can eliminate the single point failure potential designed into these lights.
See http://www.mye28.com/viewtopic.php?t=23526 for some discussion. (Shameless commercialism, with a dash of altruism).
As a general rule, whenever I hit the brakes hard, I look in the mirror to see if I need to find an escape route, just in case the meatball behind me isn't fitted with a working brain. I'd rather wind up in a ditch voluntarily (under some degree of control) than be crushed by some 'citizen' in a Fraud Exterminator.
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MisterFixit
- Posts: 1020
- Joined: Jul 21, 2006
- Location: Golden, Colorado
brake light warning
sllooo- maybe I don't understand. First you say
Andy
Then you sayI have the same issue someone on here told me it always comes on ...
It appears your warning light works normally; right?... now I just have my foot on the brake when I start the car and it never comes on.
Andy