Volt drop test.

**rallyrob** · 25-02-2018, 10:49

Hi Graham

I know you did a bad starting voltage drop test thread a few years back now.
I cant find it, can you point me in the right direction please.

I thought it was on a sticky somewhere, Ive done search but I cant find it.

Thanks
Rob

**Graham** · 25-02-2018, 11:07

i cant either but its simple, with a multi meter on volts setting, put one lead on the power supply and the other on the consumer unit and turn the circuit on, because you have one lead on say the battery positive and the other on the main starter cable which is also positive in theory the meter will read zero volts, but because every connection or wire in the circuit causes a slight resistance the volt meter will give a reading. on low power consumption circuits like bulbs the meter reading should be almost zero, but on a high consumption circuit like a starter or alternator you will always get a reading but it should not be more than 0.5 volts.

you can volt drop either the positive or negative side of a circuit