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okay so today my volt meter all of a sudden shot all the way to the right and my battery light came on. i'm thinkin 'wtf' cause that's like impossible that my alternator is producing that much power. then at other times it would go back down. and its partially rpm related because at idle it sits a little higher than usual and when i rev it the volts increase with the rpms. wtf is going on? is it my alternator? i checked the power level of the battery several times with the accessories and it seems fine.
 

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Alex said:
okay so today my volt meter all of a sudden shot all the way to the right and my battery light came on. i'm thinkin 'wtf' cause that's like impossible that my alternator is producing that much power. then at other times it would go back down. and its partially rpm related because at idle it sits a little higher than usual and when i rev it the volts increase with the rpms. wtf is going on? is it my alternator? i checked the power level of the battery several times with the accessories and it seems fine.
Take you alternator to have it tested, it could be some module inside it that is not functioning properly,
 

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sounds like a bad rectifier bridge (grouping of diodes that change AC to DC current) and voltage regulator (self explanitory). if the voltage regulator is part of the alternator, it's cheaper to replace the alternator as a whole unit (ditto with the rect. bridge). some models have a seperate voltage regulator near the alternator, and generally is a fairly inexpensive part ($10 max at a good store). you'll have to look in michell on-demand for specifics.
 

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The alternator DOES make that much voltage, but usually it is converted to 14.4V. If the electrical wiring is being shorted, it could be putting AC voltage, or high voltage (120-240).

I agree with KB.
 

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Discussion Starter #5
What does the Regulator and diode ac-dc thing look like and if it were a seperate module, where would i look?
 

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it's hard to say as there are as many designs as there are alternators. the rectifier bridge looks like a cresent, normally, with 6 or 8 diodes. 3 or 4 will be negative, the other 3 or 4 will be postive. it's near the output terminal going back to the battery. the job of the rectifier (i'll call it the RB from here out) is to turn varying alternating current to direct current, or 45 to over 200 AC volts to 13.5 to 15 volts DC. on a volts gauge, the needle staying past the high mark (normally 18 volts) and slaming back and forth rapidly is an indication of a faulty RB (and can be other things like a bad fusible link or ground). as far as the voltage regulator location or design, look up michell on-demand. ford varies the internall/external voltage regulator design. if it's external though, it will be a black box on the back of the alternator with a sensor like connector, going to the ECM. i hope this helps.
 

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Discussion Starter #7
thnx i will check that tomorrow. Also can i still drive my car for the time being?
 

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depends on what is the actual problem. high energy AC surges can really jack up your car. it doesn't take much to ruin the computer. also, overcharging the battery will make the acid boil-over and explode. it's all a matter of tolerance. driving to a locall repair shop = ok. driving down the highway = potential disaster.
 

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Discussion Starter #9
well the mechanic says its the voltage regulator and he said its okay to drive the car as long as i don't keep the rpms that high. is this true?
 

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Alex said:
well the mechanic says its the voltage regulator and he said its okay to drive the car as long as i don't keep the rpms that high. is this true?
NO!!!!


If your alt goes full yield you WILL do damage and start popping fuses do not take that risk.....


think of it this way is iy ok to smoke a cigeratte while filling your gas tank though the danger may seem minimal the what ifs could add up alot of $$$

I had my alt go full yeild do to the alt fuse not being tight enough it kept arcing and eventually killed my alt and went full yield killed my PCM auto stat and quite a few relays. Not fun to trace down everything. I have yet to fix it all and its been a year or so.
 

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Discussion Starter #11
okay, so i got ready to go to the mechanics and my battery is COMPLETELY DEAD. can the alternator do this to my battery? Is my electric system ****ed?
 

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Aye the Lat cgarges tha batt and may have destoyed it or have stopped charging it you may want to replace it with the Alt.



PS check the Alt fuse also to make sure you didnt spike it and pop it.


It is on the drivers side shock tower with a pretty little plastic casing.
 
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