Had a similar situation 2 years ago with a rebuilt alternator. Worked well for a week or two then low voltage, not charging and then the whirring noise. The culprit turned out to be the nut and lock washer(s) for pulley/fan were not installed properly which in turn means the rotor was not turning fast enough and then the the fan started rubbing on the alternator housing a little.
You’re right which is unfortunate. It’s frustrating because the problem is intermittent, so when it charges, it charges great. I don’t think there’s any lazy way for me to go about it I’m going to have to pull the alternator and get it tested. I did have an issue finding a battery so I’m curious if the incorrect size battery can have these symptoms too.
The 944 is a great daily !!!!! A odd thing will happen time to time with any car !!! Just ask the Ford Bronco owners that NEED A NEW ENGINE!!!!😂😂😂😂😂😂😂 just sayin
Thankfully this car didn’t come with a factory alarm so I’m hoping it’s not something I should have to mess with, I watched your video where that’s how you got your car up and running was by bypassing the alarm box.
The first question is did you recently swap out any LEDs into the cluster? My memory isn't 100% on this, the exciter wire runs from the alternator, meets up with the starter solenoid wire and comes to a connection on the firewall - there is a 2 pin connector near the brake booster, where they then go inside the car/dash. You can check to see if you are getting 12v at the blue wire in that 2 wire harness. The exciter wire is part of a full circuit including the ignition switch, the alt bulb, etc. But if this is a new alternator (how new?), I would assume the regulator called in sick and needs to be replaced. Did you get a new/rebuilt Bosch alternator or did you get a cheaper re-man somewhere?
This is insanely helpful thank you, I’ll check for 12v at that plug! Let me answer your questions: This car has had LEDs in the dash for over 3 years, but only for the dash lighting signals and brights indicator. All other warning bulbs are filament still, including the alternator warning light. This alternator is new as in about 2 weeks old. I ordered a manufactured Bosch unit from pelican parts that came with a pulley assembly and voltage regulator installed. I ordered it after one day my original alternator failed and the car left me stranded. It also took out my battery which was also 2 years old (they don’t last long in the heat out here and after being totally discharged it couldn’t be brought back) After the install the car fired right up and all issues seemed to be fine, until this new issue popped up about a week ago. It happens intermittently and only after the car sits for some time. When I start driving or if I leave the car alone the alternator excites and it will start charging properly 14v on cold start 13.5v once warm and with all accessories on ac hazards headlights fogs defrost cameras etc the minimum voltage comes down to 13.3. Resting voltage on the battery is 12.76. The only time it’s being discharged is after initial start when the alternator decides it doesn’t want to excite.
@@TakeFlightGarage If the Alt changed recently and the problems started then or shortly after, that is almost certainly the issue - or something in that immediate area. You can measure the voltage at the blue excitor wire, if you are getting 12v'ish then it points to the alt being the problem - you could check and make sure there is nothing loose, that a wire has a bad/failing connection or something like that, always possible given the age of everything.
Had the same problem...they rebuilt my alternator but just replaced the diodes/rectifier. The voltage regulator was failing so it would not charge properly. I fixed it myself in a few minutes and it has been good since.
Even if it isn't being excited, if you rev above 2500rpm does it start charging? The exciter wire only engages charging at startup and idle. After that engine rpm will tell the alternator to charge. My exciter wire isn't working so i just hit the accelerator to engage it
This is the exact situation I’m experiencing except it’s intermittent. Sometimes it’ll charge by itself sometimes it’ll need some encouragement (after initial startup) I haven’t had an issue where the car stops charging while I’m driving. Sounds like before I take anything apart I need to check continuity at the exciter wire. Once it starts charging it charges perfectly and the car runs totally fine.
@@TakeFlightGarage yeah I'm wondering if you have corrosion at the 2 wire plug that sits on the firewall above the brake booster... Only other place would be where the wire connects to the back of the instrument panel and uses that bulb for resistance. I need to rewire mine directly to the bulb so I don't have to rev the engine when i first start it up but it works. I accidently got a turbo alternator, I have a video of how I had to modify it. So it's the 110A and I think mine originally was the 90A. Same issue but I ended up frying mine by sending too much current to the exciter post
