[shew01]

Many of the parts I have found are advertised as 12V parts. However, for now, I think I'd like to stay with a 6V positive ground system and make smaller changes rather than make all of the bigger changes that would be required to convert to 12V. I'm not necessarily opposed to 12V in the future, but I recently purchased a new 6V horn, my 6V alternator works fine, my battery works fine, and my headlights work fine. For now, it doesn't make sense to replace a bunch of hardware that is working.

Based on the various responses to this thread, I think I have two viable paths to pursue when I purchase this heater (https://smile.amazon.com/dp/B08CZTND...v_ov_lig_dp_it) in the next couple of days or so. Please help me validate these ideas. I'm not very skilled with amps, wire gauges, etc., and I don't want start a wiring fire in my car.

Plan A (run everything at 6V):

1. Hook up the heater fans "on the bench" to see how much air output is created by the 12V fans running on a 6V battery.
2. If the 12V heater does not have satisfactory air output, proceed with Plan B.
3. If the air output is satisfactory, proceed with the following steps.
4. Add wire of my own to make the heater connections. Would 12 gauge wire be what I'll want to use?
5. Add a dedicated fuse or circuit breaker between the battery and the heater. (I have a fuse on the starter, but I'm thinking that this heater should be separated from the starter fuse. Can someone help me find a suitable fuse or circuit breaker that will work with 6V systems? This https://smile.amazon.com/dp/B07QJ2T2...v_ov_lig_dp_it is the closest I have found so far, and it's 20A. I'm thinking 10A would be what I want, but I haven't found anything 6V rated at 10A.)
6. Possibly add a potentiometer (https://smile.amazon.com/dp/B07T35JD...v_ov_lig_dp_it) for fan speed control. This is rated at 10A.

Plan B (add a 6V to 12V step up converter):

1. As in Plan A, I'll have to add some wire of my own. Would 12 gauge wire be what I'll want to use?
2. Add a 6V to 12V step up converter (https://smile.amazon.com/dp/B019GY2F...v_ov_lig_dp_it). This is rated at 10A.
3. Add a dedicated fuse or circuit breaker between the battery and the 6V to 12V step up converter. (This is similar to what is in Plan A. I need help finding the right hardware.)
4. Add a 12V fuse block (https://smile.amazon.com/dp/B07GBV2M...v_ov_lig_dp_it) to the 12V output side of the step up converter.
5. Route the heater fan connection through the fuse block.
6. Possibly route a 12V cigarette lighter outlet through the fuse block for phone charging.
7. Possibly add a potentiometer (https://smile.amazon.com/dp/B07T35JD...v_ov_lig_dp_it) for fan speed control. This is rated at 10A.

Am I at risk of overloading anything with either of these plans? Do I have circuit protection in the correct places?