Using a second meter shouldn't I be able to get a voltage reading while measuring current?
Thanks,
Rick
Rick, if the voltage at those two points fluctuate, can you please measure the following points?
1 - Terminal 1 (Battery Input)
2 - Any point 'After' the 25A Fuse. (On the 12V side of D2 or D34)
3 - Any point 'After' the L20 Inductor. (+ side of C95 or C38)
Please do this while keeping the negative meter probe on Terminal 2 (Term Ground)
VCar 'Should' be the same voltage as what your power supply is putting out, and that goes directly to pins 3 and 17 on that chip you measured... if you are getting less than 12V, then one of two things is happening:
- There is a component in-line that is a high-resistance that causes a voltage drop when current is pulled.
- The power supply cannot cope with the current draw and it dips when current is pulled.
If the voltage dips at step 1, then it's the power supply. If 1 is fine, then the other two points should let us know.
(Are you using a new fuse? It's possible for a component to fail, and still measure properly with a simple resistance reading... When the component attempts to carry load, the fault becomes much more clear.
And yes.. you can put Meter 1, in-line with the power supply and amplifier to read current, while you use meter two to poke around for voltage. Be careful though, as meter 1 may be required to pass numerous amps to your device... Make sure it's rated high enough!