so I have been wanting to put a front mount fan on my radiator for long low speed cruising to aid the mechanical fan. I still have the flathead with a 3 row aluminum radiator. I kept the car 6V and positive ground with a 6V positive ground alternator I just got new. she runs great but for some peace of mind would like to run the extra fan. I see all sorts of people doing this the other way around so call me crazy. can I use a 12v fan on a 6v car with a 6v up converter to 12v. ProblemI have seen is the converter I can only find steps up to 12v @ a peak of 1.5 amps but the fan has a draw of 12.5 amps, or should I need not to worry about the amps since its still boosted from 6v to 12v. Only other option is a 6v fan for 200$ and thats just crazy when I can get a 12v fav for way cheaper. thoughts?
thsnks for the reply and thats what I was thinking it would just run slower just as the other way around with people running the 6v heater fans on 12v speeds up difference is im not pushing behond limitations. any secinds thoughts?
Steve's right. An undersized voltage converter could even catch on fire when it fails. Get a good temp gauge if you don't have one. If you actually do have a problem, and don't have a fan shroud, adding one would be a better solution than a second fan that would be blocking airflow when it's not running.
It might not even run "slower". Most fans require a lot of power. This "power comes in the form of "amp's". The 6volt system is full of amps compared to the 12 volt system. Take my 12volt Carter electric fuel pump for instance...running on 6volts for the past 3+ years. The pressure regulator is adjusted to the minimum to cut the pressure to a reliable amount..! It's not slowed in the least (at least not noticably) from lower voltage . Mike
The 12volt fan will likely run hot keep in mind the 12v system is likely using smaller gage wire (more volts,less amps= smaller dia wire) - better off just getting a 6 volt fan and not taking the risk.
V=I*R The resistance of the fan motor doesn't change, so cutting the volts in half cuts the amps in half. If you redesign it for 6 volts, you rewire it for half the resistance. Then the amps increase to the same as it would be on 12 volts.
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