Quote:
Originally Posted by kingcobra
1. when i check the b- it only reads .05 but when i press the pedal it does drop to 0
2. the m1 post reads 0 at all times pedal pushed or not
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1. Where is this voltage reading referenced to? (Where exactly are the red and black test leads attached?)
2. M1? Perhaps that is a typo and you mean M-?
Here is what I am trying to do:
There are a bunch of MOSFETs inside the controller that control the amount of current going to the motor and by attaching your DVM test leads directly to the B- and M- terminals, you are measuring the voltage drop across the MOSFETs.
When the solenoid first clicks, the motor circuit is complete (closed loop), but the MOSFETS haven't been turned on by the throttle input yet, so the entire battery voltage is dropped across the MOSFETs. (AND ONLY THE MOSFETs)
If you do not measure full battery pack voltage, there is an open or high resistance in the motor drive circuit somewhere. High current cables & connections, F/R switch and/or Motor need to be tested to find whatever is dropping voltage and shouldn't be.
If you do get full Pack voltage, it should drop to near zero as throttle is pressed. (FWIW: The MOSFETs will drop someplace between 0.1V and 0.5V per 100 Amps of current flow through them depending on the type used.)
If the voltage doesn't drop to nearly zero, either the controller is not being told to turn on the MOSFETs by the throttle circuit, or the controller is being told to turn them on, but isn't.
Bottom line: Measuring between B- and M- terminals on controller, won't tell you what is wrong specifically, but it will tell you where to look next.