[dsraven]

that will probably do it as long as the lights are grounded to the frame or a body part that is directly grounded. on some trucks, the front lights ground to the surrounding sheet metal which may or may not be directly grounded to the battery through a cable. sometimes the lights only worked because the light housing was screwed onto something that was bolted to another body part that was bolted to yet another body part that was actually grounded. it's always best to run the light ground directly to a bare metal spot on the frame, with a star washer, then use some anticorrosion on the connection when tightened up. on newer vehicles you will find a ground distribution wiring diagram where several accy have been wired to a common ground wire that has a dedicated grounding area on the vehicle. there are usually several f these in the system.
a good way to check for a poor ground, if the lights are dim or the heater fan seems slow, is to use a long test wire connected well to the battery ground, then turn on the light or accy in question and use the test wire as a ground for that accy. if you get proper operation then the problem is a bad round. a test light can also be used if it is grounded like normal and then when the tester is touching the ground of the accy, if it lights up dimly then there is a voltage difference there so that indicates a poor ground connection for that accy.
sorry, that got long winded.