This makes absolutely no sense to me. To qualify this, the fuse would still do the job if the fan motor developed a short in the windings, because current is equal throughout a series circuit. However, if for some reason the positive lead were to touch ground incidently, the fuse would be negated from the circuit! The battery would have a dead short with no protection. I would consider buying another fuse holder and an equal value fuse to put on the positive side as well. it couldn't hurt, and will give you double protection without violating the manufacturers specs.Tresguey said:the instructions state to go direct from 12 pos batt. to the first leg of the toggle switch from the other leg of the switch go to the pos side of the fan. then tie in the ground side of the fan to the inlilne fuse and ground direct to chasis ground.
Yes, this is "theoretically" true, but, a fuse offers the best protection when it is placed on the positive or hot side of the load, not the ground side. As I stated earlier, if an internal short occured in the fan motor, yes, the fuse would blow regardless to where you put it in the circuit, but, say for instance another TYPE of short occured : Example/ the positive wire of the fan became brittle and the copper exposed, and this wire touches a chassis grounded metal panel or bolt, a short would develop from the battery to ground, totally bypassing the motor and fuse and elemenating the effectiveness of the fuse, and a fire could start! Where, on the other hand, as Stevez pointed out, if you locate the fuse as close to the battery as possible, you reduce the amount of wire that is not fuse protected. If this same short occured, the fuse would be BETWEEN the positive terminal and ground, and would open. So, the engineers who suggested that it doesn't matter where the fuse is located are fools._3iMaJ said:My initial guess would be because current flows from ground to positive. But as I said thats just my best guess.
Perhaps the people who wrote the instructions have no idea what they're talking about? Just a theory. What kind of electric fan is this? Got a brand/model #?Tresguey said:i recently purchased a electric fan for my car. and the instructions stated to install the fuse on the ground side not positive side. why is that? :?: