FOOTWELL LIGHTS dimming with map lights and turning back on with headlights

Thread Starter

paki

Joined Dec 16, 2022
28
Thanks a lot sghioto i will try your metod its much simpler then mine. Amperage of led strips is about 0.96 almost 1A i cant find 2A diode. Can I use 1N5408 its 3A diode
 

Thread Starter

paki

Joined Dec 16, 2022
28
Im thinking of maybe putting a switching step down regulator module such as LM2596 between loop of d2 and d3 and led strip just for safety. Because if im right, if my map lights are on and ignition is on voltage that is going in to the led strip is about 24v and my led strip is rated for 12v. Please correct me if im wrong
 

sghioto

Joined Dec 31, 2017
5,376
Because if im right, if my map lights are on and ignition is on voltage that is going in to the led strip is about 24v and my led strip is rated for 12v.
Doesn't work that way, the voltages do not add up. When the Ignition is ON diode D3 blocks the 12 volts from the map lights.
Did you ever get it to work with the two relays?
 

Thread Starter

paki

Joined Dec 16, 2022
28
I have install this circuit today 1671225332814.png
and it doesnt work like its should same problem as before when i used 2 relays. If i connect everything leds are only work with map lights if i disconnect map lights then leds are geting power from headlights but together they dont work. Please help its driving me mad.
 

MisterBill2

Joined Jan 23, 2018
18,167
First of all, there is no reason to have that diode across the relay coil. The coil is in parallel with other items that very well absorb whatever transient might be generated when it is switched off.
Next, we do not get a specific statement of what conditions are supposed to switch the new LED strips ON.
Normally, footwell lights come on when the door is opened, no matter about any other condition. That is because a person might open the door to enter the vehicle at night, when the headlights are off and the engine is off and the vehicle is parked. Usually when the doors are closed the foot-well lights should not switch on when the map lights are switched on to read a map.
What might be a problem, depending on the year and model, is that the electronic control is sensing excess current and switching off the power feed because it assumes that there is a ground fault someplace.
 

Thread Starter

paki

Joined Dec 16, 2022
28
My headlights are turning on only at night via sensor on windshield. I want led strip to work like map lights but i also want them to be turned on when headlights are turned on
 

MisterBill2

Joined Jan 23, 2018
18,167
My headlights are turning on only at night via sensor on windshield. I want led strip to work like map lights but i also want them to be turned on when headlights are turned on
Do you mean only able to turn on when the headlights are on? Or to be constantly on whenever the headlights are on, and still switching on when the door is opened? OR switching on whenever the map light is manually switched on?
Having the foot-well lights on while driving will be distracting. It may not even be legal in some parts of the world.
 

Thread Starter

paki

Joined Dec 16, 2022
28
Yes i want them to be constantly on whenever the headlights come on and still switching on and off when i open and close car with key
 

MisterBill2

Joined Jan 23, 2018
18,167
Yes i want them to be constantly on whenever the headlights come on and still switching on and off when i open and close car with key
OK, then you can use two diodes rated for the light strip current plus an adequate amount more. at least 5 amps, ten amps will be better. One diode feeding from the map lights feed, and one diode feeding from the headlights feed, like D2 and D3 in post #27, but without the relay. That should achieve what you want, UNLESS the control computer decides that there is an overload and goes into some system fault mode.
 
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Thread Starter

paki

Joined Dec 16, 2022
28
I now tried it to wire ground to the chassis and then leds are constantly on even if i lock the car.
 

sghioto

Joined Dec 31, 2017
5,376
OK, then you can like D2 and D3 in post #27, but without the relay..
The relay is required because the Day Light Running Lights are also in the mix.
The circuit should work as designed if the map lights are switched on using the positive voltage. I suspect the map lights are controlled by switching the negative side.
 

sghioto

Joined Dec 31, 2017
5,376
I now tried it to wire ground to the chassis and then leds are constantly on even if i lock the car.
Do you mean you connected the negative side of the LED strip to the chassis?
If so and the LED strip is constantly ON would be an indication the map lights are controlled by switching the negative side.
 

sghioto

Joined Dec 31, 2017
5,376
If the Map Lights are controlled through the negative side then the fix is going back to using 2 relays as shown below.
RL1 controls the DLR and RL2 controls the LED strip by switching the negative side of the LED strip.

1672511455954.png
 
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Thread Starter

paki

Joined Dec 16, 2022
28
Yes thats right i connected negative side of LED strip to the chassis and they are constantly on.
 
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