Rustyms3
Greenie N00B Member
(2007 Mazdaspeed 3)
I recently threw a belt after I had just replaced it. I don’t know what caused what but the alternator was stiff afterwards. I ordered a reman from a local parts store. (I’m not spending 500 on a new one). The old alternator was charging fine before all of this happened. (The new alt is a 3 wire and I don’t know what my old one was) I replaced the alternator and belt. The new alt will not charge. I can’t find any wiring diagrams over the engine or charging system. The excite wire is NOT getting hot, no matter what I do. I’ve traced the grey wire in the alternator plug in back to the ecu. I have continuity all the way to the plug on that wire. I believe that’s the battery light wire as the alt is internally regulated. The green wire which I suspect is the excite wire runs back to the fuse box and joins like 5 other green wires in a junction that leads into one bigger wire in the engine fuse box. That wire is hot at the box. I get no connection testing between the green at the fuse box and the green at the alt plug. I took a wire and essentially “hot wired” the alternator. The alt still does not charge. I’m at a loss. This car has challenged me in every possible way and most of it still has no answer. I’ve built ecus and tuned turbo cars but apparently nothing I’ve done compares to the complexity of gosh darn internally regulated alternator wiring. Thanks I’m advance.
I recently threw a belt after I had just replaced it. I don’t know what caused what but the alternator was stiff afterwards. I ordered a reman from a local parts store. (I’m not spending 500 on a new one). The old alternator was charging fine before all of this happened. (The new alt is a 3 wire and I don’t know what my old one was) I replaced the alternator and belt. The new alt will not charge. I can’t find any wiring diagrams over the engine or charging system. The excite wire is NOT getting hot, no matter what I do. I’ve traced the grey wire in the alternator plug in back to the ecu. I have continuity all the way to the plug on that wire. I believe that’s the battery light wire as the alt is internally regulated. The green wire which I suspect is the excite wire runs back to the fuse box and joins like 5 other green wires in a junction that leads into one bigger wire in the engine fuse box. That wire is hot at the box. I get no connection testing between the green at the fuse box and the green at the alt plug. I took a wire and essentially “hot wired” the alternator. The alt still does not charge. I’m at a loss. This car has challenged me in every possible way and most of it still has no answer. I’ve built ecus and tuned turbo cars but apparently nothing I’ve done compares to the complexity of gosh darn internally regulated alternator wiring. Thanks I’m advance.
