The alternator replacement thread, Fixed! |
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The alternator replacement thread, Fixed! |
VaccaRabite |
Aug 12 2018, 07:07 PM
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#1
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En Garde! Group: Admin Posts: 13,444 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
Waiting on the side of the road for a flatbed to take me home.
Engine ran great. Charging system not so much. Driving along. Lights started going dim. Car started bucking. Only 5 miles to home but it wasn’t going to make it, and no shoulders to pull over safe on the little farm roads. So I pulled into a spot I knew of and shut it down and parked it and now I wait. McMark had said earlier he wasn’t sure about the charging system. But the alt light was not on and no issues before now. So. What’s the alternator I need to buy? Maybe a new VR as well? I guess I should test the battery and make sure it’s okay too. Zach |
Spoke |
Aug 22 2018, 07:54 PM
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#2
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Jerry Group: Members Posts: 6,978 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
While you have the relay board out, measure the resistance between the D+ to D+, DF to DF to Pin 2 of the cabin connector, and D- to D-.
You can see by the schematic below that the relay board doesn't do too much for the alternator except provide a place to mount the voltage regulator and provide a wire back to the dash for the GEN light. You shouldn't be killing alternators that easily. Check all grounds and the transmission strap. When you had your engine out you didn't paint or powder coat the fan shroud? The alternator is grounded to the shroud and the only direct ground connection to the engine case are the 4 little studs attaching the shroud to the engine. The tin might also provide some grounding but it's really those little studs providing the most grounding. Attached thumbnail(s) |
VaccaRabite |
Aug 22 2018, 09:34 PM
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#3
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En Garde! Group: Admin Posts: 13,444 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
While you have the relay board out, measure the resistance between the D+ to D+, DF to DF to Pin 2 of the cabin connector, and D- to D-. You shouldn't be killing alternators that easily. Check all grounds and the transmission strap. When you had your engine out you didn't paint or powder coat the fan shroud? The alternator is grounded to the shroud and the only direct ground connection to the engine case are the 4 little studs attaching the shroud to the engine. The tin might also provide some grounding but it's really those little studs providing the most grounding. I did in fact powder coat the shroud and tins. That could be it. I’ll run a ground wire from the alternator bolt to the engine case. My other grounds are all golden. Trans, battery, and wire harness all made solid connections. I did not know about how the alternator grounded though. Zach |
Spoke |
Aug 23 2018, 04:42 AM
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#4
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Jerry Group: Members Posts: 6,978 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
I did in fact powder coat the shroud and tins. That could be it. I’ll run a ground wire from the alternator bolt to the engine case. My other grounds are all golden. Trans, battery, and wire harness all made solid connections. I did not know about how the alternator grounded though. Zach If you didn't scratch off the powder coating from around the shroud mounting studs, the alternator not being grounded is a possibility. A grounding wire from the alternator case to the engine case is a good idea. Before you do this measure the resistance from the alt case to engine case. It should be zero ohms. Use a heavy wire like the one going from the alt to the starter. There was another 914 owner who had charging trouble and also realized the accelerator cable was getting hot. It turned out the alternator was grounding through the cable. |
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