Check the backup lamps to see if they work. If they do not, suspect an open fuse link, (wire), just inside of the left strut tower. They are in a bundle, tie strapped together, and the individual wires will be green, gray, and orange. If you pull on them one at a time, and it acts like a wire, it's good; if it acts like a rubber band, it's burned open.
If you find one that's open, you might want to test the old fan motor with a battery and a pair of jumper wires. If the motor squeals, smokes, or the wires get hot, the motor may indeed have caused the fuse link to burn open. More likely, you'll find the old motor is fine and wasn't the cause of the problem.
Some people solder in a weatherproof fuse holder in place of the fuse link because they can be a chore to replace. This can be a good idea for a temporary repair, but a fuse is not forgiving of the intermittent high current surges and could blow unnecessarily. Replacement fuse links are available at auto parts stores. The color indicates the current rating, and you will get enough wire for two repairs. Don't use regular wire. The insulation on fuse links is designed to not burn or melt.
One disadvantage of fuse links is experts often get fooled when troubleshooting the circuit. If you unplug the protected item in the circuit, and measure for voltage with a voltmeter, it will appear to be present but only because a little tickle of current gets through the carbon trace left behind when the wire burned open. More accurate results will be found by using an inexpensive test light instead of the more expensive voltmeter.
If the old motor was defective, go ahead and replace the fuse link by removing a little insulation from the fat wire feeding the black rubber triangular joiner that the other fuse links come out of and soldering one end to the new fuse link to that spot. Cut the other end of the fuse link and the heat shrink tubing from the wire. Slide a piece of heat shrink tubing onto one of the wires, then splice and solder them together. Slide the tubing over the splice and warm it with a match. Don't overheat it or it will melt. Silicone sealer works well for sealing moisture out of the repair on the fat wire.
If there is enough of the old fuse link left that you can splice the ends together and seal them with heat shrink tubing, it will make the job a lot easier, but if the old fan motor was not defective, you might want to consider temporarily installing a fuse holder and regular fuse because this will likely be an intermittent problem, and the link will burn open again soon. If you find that the new fan runs fine, but a day or two later the fuse is blown again, suspect a wire in the harness under the battery tray rubbed through and is intermittently grounding to the inner fender. This harness moves back and forth when the engine rocks from changing between drive and reverse. Although the backup lights do have their own fuse, the entire circuit receives its current through the same fuse link that feeds the fan motor circuit. That's what makes the backup lights a quick clue when troubleshooting this circuit.
Friday, May 22nd, 2009 AT 1:37 AM