so, i'm the driving the Q, and I notice the temp gauge is reading a bit low. Curious since it's 88 outside and I got the AC going strong.
10 min later, it's definately down just a hair, but down nonetheless. I'm wondering what could be causing that. Suddenly the AC starts cycling on and off in about 3 sec intervals.
SERENITY NOW!
Battery voltage is low! Alternator is a 40 pound boat anchor.
Anyone know a good place to get an alternator rebuild kit? Are these sold in any channel but dealer?
Test shows the rectifier bridge is out. I better replace the IC and bushings while I've got it apart.
rectifier bridge!
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Q451990
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I repaired my alternator once... the diode pack (maybe we're talking the same part?) was bad. A year later the stator starting shorting out intermittently. I replaced it with a new unit from Scottsdale. These things are a real pain to replace unless you move the compressor, which I think has flex lines, but I'm a little nervous flexing 13 year old lines if I don't have to... You can buy the parts separately, but if you replace the brushes, front and rear bearings, and the diode pack, you're getting close in price to a new or remanned unit - I think I'd just go ahead and get the whole assembly.
Heath
Heath
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szh
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Unfortunately, no longer a Nissan or Infiniti, but continuing here at NICO! - Location: San Jose, CA
You are right, rectifiers normally use 4 diodes. Out of curiosity, why does the car one take only 3?forecast wrote:i think you're right. I did a little shopping for parts and saw that.
the three diodes together form whats called a rectifier bridge, which is a lot more fun to say.
In household electronics 4 diodes are used in the process of turning AC current into DC current.
Z
The alternator works thus:
An IC measures system voltage and outputs a variable current to the rotor coil through the brushes. This current forms a magnetic field of varying intensity (based on current supplied).
The output of the IC is also reported in many cars in the dash by a light, a high IC output indicates the alternator can't keep up. On the Q that light doubles as the brake warning light.
Many alternators also have a test point. Grounding this point bypasses the control IC and causes the alternator to generate as much current as possible.
As the rotor turns the magnetic field sweeps through three fixed coils. An alternating current will be generated in the fixed coils. The coils are spaced so that the peak voltages will be out of phase with each other.
Each of the three diodes (or diode pairs) allows current to flow out into the system.
An IC measures system voltage and outputs a variable current to the rotor coil through the brushes. This current forms a magnetic field of varying intensity (based on current supplied).
The output of the IC is also reported in many cars in the dash by a light, a high IC output indicates the alternator can't keep up. On the Q that light doubles as the brake warning light.
Many alternators also have a test point. Grounding this point bypasses the control IC and causes the alternator to generate as much current as possible.
As the rotor turns the magnetic field sweeps through three fixed coils. An alternating current will be generated in the fixed coils. The coils are spaced so that the peak voltages will be out of phase with each other.
Each of the three diodes (or diode pairs) allows current to flow out into the system.