I have a 1981 Camaro with a LM7 Engine swap (LS1 intake). I have had 5 radiators in it and seem to have an electrolysis issue.
Currently I have a new aluminum radiator, new 50/50 Prestone antifreeze and distilled water.
Right after putting fluid in I checked for a charge in the cooling system by attaching negative voltmeter to negative battery terminal and dropped positive in the antifreeze in the radiator.
The meter read .19 volts. I ran the engine for a bit, letting it get up to temp and it read .8 volts. I tested my battery when it was running and it was at 14.9 volts. I think this might be high as it should be around 14.3 I think. Is this enough to cause the stray charge in my coolant?

I grounded the negative battery terminal to the engine block, core support and body. The engine is grounded to the frame and firewall. I ran a ground from the radiator to the core support.
I tested my engine's ground with the engine on and off by placing the positive volt meter to positive battery terminal and placing the negative to the engine block. Volt did not drop which means the engine has a good ground.

How can I find where the stray charge is coming from?

Thanks,

MTmace

 

14.9 isn't enough to cause stray current. a failing diode might though. run the vehicle to the parts store and let them do a full charging system test. The definitive way for testing a ground though is checking resistance. checking voltage (even i do it) is a lazy man's test cause we don't want to disconnect power. disconnect that negative cable and test resistance from the battery terminal to the various grounds and even the radiator itself. the radiator should be electrically isolated from the rest of the vehicle.