i have one of those cheap testers that look like a pen.

what parts of the car can i clamp the clamper down to?

what part do i touch with the tip, the positive or negative?

will it still work with solder on it?

 

You can connect the clamp to most any metal unpainted surface
on the vehicle..Usually a bolt head will work.

If the clamp is connected to ground,Then you would touch the tip to positive..

You can also use the tester in reverse,
Clamp the end to the positive terminal and use the tip to establish ground..
Either way,if the circuit is completed,the lamp should lite..

Just don't hook both sides to positive or it will blow the bulb...