Maxwell85

Maxwell85

Member
Here’s one for you;

I bought an led brake light to replace my high level one. Plugged it in and it didn’t work, being led I thought it may be reverse polarity so I changed the polarity over. Now the light is always on until I push the brake pedal as LED’s only work one way.

any ideas how I get it to work as it should?

it’s confusing me just thinking about it....
 
Interesting!
Pushing the brake pedal must be breaking a circuit instead of making one. As if it is wired to continuous positive through the brake pedal switch I wonder if you have accidentally wired it to part of the cruise control? There are three wires to the brake pedal switch for this reason. Have you replaced the brake pedal switch recently? You could have rewired it accidentally the other way round and this has been going on ever since! Pushing the brake switches cruise OFF remember!
Did you simply wire it to the original wires that normally connected to the old hi-level lights? Which would be the obvious thing to do.
You seem to be happy playing with LEDs. As they are already 12v no need for a driver. If it was me I'd take the bulb out and test the contacts at the hi-level to check that there is only 12v feed to it when the brake pedal is depressed. Then check the other contact has a good earth.
Maybe you have somehow got backfeed through the earth.
Intriguing!
Keep us posted, would love to know what you find. Meanwhile why not replace the old hi-lev and check it still works!
My betting is you'll find the old hi-lev is doing the same thing!
 
Stanleysteamer said:
Interesting!
Pushing the brake pedal must be breaking a circuit instead of making one. As if it is wired to continuous positive through the brake pedal switch I wonder if you have accidentally wired it to part of the cruise control? There are three wires to the brake pedal switch for this reason. Have you replaced the brake pedal switch recently? You could have rewired it accidentally the other way round and this has been going on ever since! Pushing the brake switches cruise OFF remember!
Did you simply wire it to the original wires that normally connected to the old hi-level lights? Which would be the obvious thing to do.
You seem to be happy playing with LEDs. As they are already 12v no need for a driver. If it was me I'd take the bulb out and test the contacts at the hi-level to check that there is only 12v feed to it when the brake pedal is depressed. Then check the other contact has a good earth.
Maybe you have somehow got backfeed through the earth.
Intriguing!
Keep us posted, would love to know what you find. Meanwhile why not replace the old hi-lev and check it still works!
My betting is you'll find the old hi-lev is doing the same thing!
Click to expand...
Have literally unplugged the original and replaced with the LED, haven’t touched anything else.

The other brake lights work as normal.

completed stumped
 
Where did you buy the LED bulb from? Are your sure it's an 1156 bulb an not an 1157 bulb?
1156-1157-bulb.jpg
 
Maxwell85 said:
I bought an led brake light to replace my high level one.
Click to expand...
So the original one didnt work i suppose... though are you sure that the bulb was shot not bad earth?(cos then it might be an answer) ...also do you have a 12S caravan socket fitted?
 
Last edited:
sierrafery said:
So the original one didnt work i suppose... though are you sure that the bulb was shot not bad earth?(cos then it might be an answer) ...also do you have a 12S caravan socket fitted?
Click to expand...
The old one was on the back door, I’ve chopped the back off the car to make into a pickup. Just bought an aftermarket LED stop light off eBay, put some spade connectors on it and plugged it into where the old connectors for the stop light are.
 
Maxwell85 said:
The old one was on the back door, I’ve chopped the back off the car to make into a pickup. Just bought an aftermarket LED stop light off eBay, put some spade connectors on it and plugged it into where the old connectors for the stop light are.
Click to expand...
As you said in your opening post, so I don’t see how it came that it was assumed the bulb was iiffy.
I assume your new stop light is of the high level version so with a pos and neg pair of wires and not one of the pulsating flash, anyway why no check if the item works when connected directly to a 12v battery, if okay, test the existing wiring u intend to use to feed the unit for a 12v and an earth. Something is either missing or u have a faulty unit.
 
Maxwell85 said:
The old one was on the back door, I’ve chopped the back off the car to make into a pickup. Just bought an aftermarket LED stop light off eBay, put some spade connectors on it and plugged it into where the old connectors for the stop light are.
Click to expand...
I'm confused... so where is that "high mounted" brake lamp fitted now if you dont have a tail door? ...anyway connect a ''classic'' bulb to those wires and see what happens then cos IMO it's a bad earth there, according to the result i'll tell you more
 
sierrafery said:
I'm confused... so where is that "high mounted" brake lamp fitted now if you dont have a tail door? ...anyway connect a ''classic'' bulb to those wires and see what happens then cos IMO it's a bad earth there, according to the result i'll tell you more
Click to expand...
Presumably you will have a bar or summat on the back of the cab, or on top of the tail board?
 
Well, its not road legal without anything covering those rear wheels...

As said, stick in a normal bulb and try it...
 
Its not working - probably an earth issue
When you put it in the "Wrong Way" it comes on and goes off when you press the brake pedal so -
You have a poisitve feed on the earth when you put the bulb in the wrong way it is "earthing" out through the other brake lights hence why it is on
When you apply the brakes you are putting 12V on both sides of the bulb it goes out
When you put it in the right way you have 12 V on the earth so it will never come on
 
You must log in or register to reply here.

Similar threads

Paddy78
L322 Led help
Replies
2
Views
396
Graculus
Graculus
D
Tail lights not working
Replies
2
Views
211
miktdish
miktdish
R
LED side lights not working
Replies
9
Views
742
RickyFreelander
R
J
LED lights
Replies
9
Views
1K
miktdish
miktdish
J
Brake lights
Replies
3
Views
401
miktdish
miktdish