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simulating a power draw

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aermet

New Member
I need to know how to simulate a power draw in a circuit. Please let me explain.

I've installed a HID headlight on my motorcycle that had a stock H4 55/60 watt bulb OEM. The issue I'm having is that since the new HID setup is not powered off the stock 3 prong headlight plug, it appears that the canbus/main dme computer is sensing that there is a bulb out and is giving me a lamp fault on my display on the dash. The voltage running through the headlight bulb when engine is on and bulb is lit is 13.8 volts. As mentioned, the bulb is a 55w low and 60w high beam.

The way the new HID system is set up, it is powered from the battery so does not draw any appreciable current through the factory bulb plug, hence the computer thinking that a bulb is out and subsequent lamp fault. The OEM factory plug is still used in the system, but just as a switch to tell the igniter/ballast to turn on but does not power the bulb and the draw is obviously too low.

Perhaps I'm a ways off but I tried to use a 4 ohm 50W resistor inline on the ground wire at the stock headlight plug on the HID side to simulate a current draw. The exact resistance I came up with based on 13.8V and a 55w bulb was 3.46 ohms but I figured that 5 ohms might work assuming the computer won't produce a fault until a certain threshold, below the 47w/5ohm resistor value.

So, is it incorrect of me to wire the resistor inline on the ground wire? Am I completely off with how I want to trick the circuit?

thanks in advance
 

aermet

New Member
Would anyone care to give a suggestion? I'm not sure that I'm even approaching my problem with the right solution. This problem seems elementary compared to some of the projects I've seen posted.
thanks
 

tesla2008

New Member
I need to know how to simulate a power draw in a circuit. Please let me explain.

I've installed a HID headlight on my motorcycle that had a stock H4 55/60 watt bulb OEM. The issue I'm having is that since the new HID setup is not powered off the stock 3 prong headlight plug, it appears that the canbus/main dme computer is sensing that there is a bulb out and is giving me a lamp fault on my display on the dash. The voltage running through the headlight bulb when engine is on and bulb is lit is 13.8 volts. As mentioned, the bulb is a 55w low and 60w high beam.

The way the new HID system is set up, it is powered from the battery so does not draw any appreciable current through the factory bulb plug, hence the computer thinking that a bulb is out and subsequent lamp fault. The OEM factory plug is still used in the system, but just as a switch to tell the igniter/ballast to turn on but does not power the bulb and the draw is obviously too low.

Perhaps I'm a ways off but I tried to use a 4 ohm 50W resistor inline on the ground wire at the stock headlight plug on the HID side to simulate a current draw. The exact resistance I came up with based on 13.8V and a 55w bulb was 3.46 ohms but I figured that 5 ohms might work assuming the computer won't produce a fault until a certain threshold, below the 47w/5ohm resistor value.

So, is it incorrect of me to wire the resistor inline on the ground wire? Am I completely off with how I want to trick the circuit?

thanks in advance

i am no expert but my coworker solved this problem when he upgraded his BMW to HID lights.

he used a resistor that he plugged in the each light bulb socket.
if i were you, I'd try to do some tests with different resistors, then pick the value that seem to work most reliably.
Say, if 10 ohm turns off the warning light then I would use maybe 5 ohm (just to make it a bit more stable) as you said that exact resistance was 3.46 ohm.
 

mneary

New Member
Your solution gets hot and wastes a lot of power. Someone else here found that he only needed to draw a fraction of the rated current. If I recall correctly, he satisfied the warning circuit with 1 Amp. A convenient way to achieve this is to wire a lamp (marker or stop, etc.) someplace where it isn't visible from the outside.
 
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