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Showing content with the highest reputation since 06/14/2025 in Posts
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I did install the the the less expensive C4 fan (996 624 135 00) in the C4S with the following results. 1. Fan is the same diameter and size. 2. Motor diameter and flanges are the same size and will bolt into radiator shroud. 3. Offset of motor flanges are different, moves the fan 1/4 inch closer to radiator. 4. Changed style rubber grommets in shroud to gain 1/8 more clearance, but fan is still closer to the radiator than the stock fan. I'll let you know if the spacing gives me any problems.1 point
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Dave, As Silver said, it should not be too difficult to track down the problem(s). All you need is a $15 multimeter. Run your engine till warm and the low voltage shows up, then let it idle and turn on the a/c and the low beam. The current draw from the alternator should now be ~50A. You can then do the following tests. I drew a diagram with the corresponding parts. Test #1: check voltage drop between point "C" (alternator casing) and "B-" (call that V(C, B-)). Note "B+' and "B-" are the actual battery terminals, not the cable connectors on the terminals. This test shows total voltage lost between the alternator and the battery on the ground side. Expect 0.2v or less. If your ground strap is bad, it will show up in this test. Test #2: check V(A, B+) where "A" = alternator output at the back of the alternator that you can't see (use an inspection mirror) and expect ~0.5v or less. "A" is hard to get to. I fabricated a J-shape hook using a stiff insulated wire and just literally probe it blindly from behind. Wear protective goggles here since you will be close to the drive belt, a hot engine, and the always LIVE "A". This test shows total voltage lost between the alternator and the battery on the power side. Test #3: check V(A, J) and expect ~0.2v. This tests #21, which is the infamous cable that can corrode and Porsche has also revised it. Test #4: check V(J, B+) and expect ~0.3v or less. Test #5: check V(A, C), your alternator output and expect 13.5v or higher. Your problem is gonna show up in one of the tests above.1 point