electrical:someone has to have had this problem before

[Andre]

86 944 na

while driving: voltage gauge reads about 12, and jumps around frequently(sometimes upto 14 then back down to 12) While at 12 all the gauges(ie:rpm, water temp) bounce around.

If i stop and try to start it, a lot of the time it wont start and just click. Then randomely it will start again and everything will be fine and 5 min later voltage problem again.

I replaced the alternator with a rebuilt one and the problem persists. I just went to get the amperage checked and the alternator is giving off 65, its supposed to give off 115. Did i just get a bad rebuild?

what would cause the alternator to give off less amperage?i checked the grounds on the battery and on the block, should i check the started ground, could that cause the voltage problem?

someone PLEASE HELP i'm stuck

[AFJuvat]

I would check your grounds just to be sure, However, I'm willing to bet that if you got a rebuilt one from an auto parts store, you probably got a bad rebuild - my first replacement alternator failed after 3 months - the rebuilt parts just aren't designed to handle the stress/load on the alternator. Remember, the factory calls for the alternator belt to have a maximum deflection of 5mm in the center of the belt - in laymans terms, that is like a guitar string. The rebuilt ones call for a belt with a lot more slack.

Got myself a good bosch rebuilt unit - had it in the car for almost a year - not one problem.

If you return your alternator, make sure to get the money you paid, AND the core charge back - since they probably don't have your core anymore


AFJuvat

[maachan]

Hi,

If I were you I will have that alternator bench tested at any good auto part store where they can provide the service. Also I will check the battery, load test it.

I may even try to have jump start the engine using other car's battery. Or I may put the oter car's battery in the Porsche for testing, because your battery may not be healthy one.

Good luck,


Maachan

[maachan]

Hi,

I foregot to say to check the battery posts as well.

Maachan

[todwic]

1. ALWAYS check your battery posts as your first culprit on any electrical problem. I have had bugs in not just my 944, but in other vehicles as well, that seemed like a bad starter, alternator,voltage regulator and other things and I just needed to clean my posts. Do that firsty first.
2. bench tests at automotive (esp. discount chain [ie Autozone, Pepboys]) stores are somewhat lacking because they are done on antiquated equipment by people who haven't the foggiest f*** of an idea on how to run a proper test. Ford voltage regulator leaps to mind. I had it tested along with a plethora of other electrical parts, all of which tested good. 2 mo. later I change the regulator in frustration and the vehicle fired right up.

[maachan]

Hi todwic,

Does your disclaimer aply to me? Since I am the person above?

Please note I said go to any GOOD auto parts store for bench test an alternator. The store with qualified equipment and personel may be a GOOD store. I have never had bad experience with such GOOD store. I also know a shop in Boynton Beach, Fla. It's a one man shop who specialise in DC motors and alternators. I am sure there are many shops like that throughout in GOOD OL' USA.

I have never owned a Ford so I am not sure about thire electrical system. Does voltage regulator has something to do with starting on Ford? Is that why your Ford fired right up after you change the regulator?

Maachan