New to forum. Saying howdy and asking questions. Just bought a 86 f250 w/6.9. The wire going to the heated fuel line was burned into. 1-How can you test to see if the heater is good ? 2- How does it affect performance with vs without. 3- Does it do enough to warrant replacement, and is it controlled or does it stay heated all the time. Thanks in advance for any advice. p.s. Live in SC. Not very cold.

I live in buffalo Ny where it is currently a hearty 20 degrees last week it was in the 0-10 degree range of my 7 IDI powered engines None have the heater hooked up anymore .. never have had a problem this heater only works when the key is on so in my opinion its a redundant device since the line runs right beside a exhaust manifold the radient heat from there will warm the fuel just as well