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Power functions problem

Hi All!

I have a question regarding some none working power-functions. The situation is as following:
1 IR receiver:
Connection 1: 1x Servo
Connection 2: 2x L motor.

The IR receiver is connected to the battery box, with on top of that a power functions control switch (connecting to a M motor). On top of the control switch connector is a LED connector.

Now, the following works: LED, Control Switch + M motor and then the problem shows up:
Only the L motor connected "closest to the base of the IR receiver" works.
If motor 1 is "on the bottom" that one works. If motor 2 is on the bottom, that one works.
Both at the same time does NOT work.

It seems to me that the problem lies either in the IR receiver or in the power consumption of the 2 L motors.
However; I find this somewhat strange since it's Lego's own set up and other (on youtube) seem not to have any problems with it ... so I am a bit puzzled...

Can anybody help me understand and solve this?


  • PaperballparkPaperballpark Member Posts: 4,270
    I suspect you're simply connecting too much to the one system. Do you have version 1 or version 2 of the IR Receiver? If you have v2 it'll say 'v2' clearly on the front of it. I think V1 had some issues with how much it could run, whereas v2 fixed that. That said, I don't remember ever having any issues 'double stacking' motors on an IR Receiver, although I've never used L motors.

    Have you tried a different IR Receiver? Have you tried them on the other side of the receiver? Try two M motors, or other combinations - for example, an L motor and the LED. Have you tried the two motors without anything else on the receiver or battery box?

    Use a process of elimination. Try lots of different things, and note what works and what doesn't. Start simple and work up to the more complex combinations.
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