Positive to Negative Conversion

[memphis]

Hi All!

I have a really dumb question....

In reading the conversion steps of changing our cars from positive common (ground) to negative, once you flip the battery connections, things like the fuel pump only require you to also flip their wires around. Sounds easy...

So my question is, with the car setup as positive common (ground), why cant we just flip things (modern devices) like radios and cig lighter wires around and use them this way? Why do those devices need a power converter to run on a positive ground setup? Very puzzling for me...

Thanks for your comments.

Bob

 

[John_Progess]

I believe most SU type fuel pumps will require a wiring change. The little square aftermarket pumps do not. Most modern electrical devices use their attachment method (clamps,brackets,bolts etc.)for the grounding which is usually negative. In a positive ground car you must isolate the device body from the positive car body. Also if you have electronic ignition of a electronic tach it is polarity sensitive. Have a good day!

John

 

[dancrim]

This is because new fangled things like radios etc. use transistors and polarity
sensitive capacitors. They run on negative ground and can be damaged if reversed. Also your stock fuel pump cannot simply be reversed. You need to check if it has a capasitor in it and reverse that. Check online for Pos. Neg.
conversions.