Hi guys, I'm installing a manual radiator switch on a 93 Buick Century. The fan has two wires, solid black and black w/red stripe, and I need to know which ones are negative and positive. I don't have a voltmeter or test light.

Any help would be greatly appreciated!

hook them up to a battery, the position that makes it spin the right way is right. make sure to wire in a relay, fans draw alot of power and even if the switch is rated for it they tend to wear out fast

If all you are doing is installing a switch, it shouldn't matter which wire you use, but I would not do that if I were you. Justin is right about wiring in a relay. You don't want to wire in that much current draw into a switch inside the passenger compartment.

Well, I've done everything under the sun in terms of jumping wires and I'm guessing the fan motor itself is bad.

First, I replaced the relay, which did nothing.

Then I hotwired it to the battery, which did nothing. Even tried it with a switch just for the hell of it.

Oh well, just have to buy a new motor and see if that'* where it'* bad.

if you ran wires to the battery and it didnt do anything its bad. even if you get the wires in the wrong direction it will spin backward if its good