Possiable alternator failure

[Q_SHIP]

About 2 months ago I was having this same issue.

I'll be driving down the highway, cruise on. I hit my high beams and everything goes dim and even kicks the car out of cruise. This even happens when I hit my brakes.

Now like I said, I had this happen 2 months ago as well and the issue just went away. What do you think?

[Jesda]

Its in the process of failure. My brother's G20 did the same thing. The symptom was rare, then random, then frequent, then it finally died for good six months later.

[lino]

Definitely check alternator + battery condition. The lights on my car got dim when the alternator failed. My car was on the highway when it happned and I never saw it coming. I noticed that the pulley and belt condition weren't the greatest. I'd inspect those too.

When the cruise control wouldn't engage in my Mercedes, it turned to be that the reverse light bulb was an aftermarket (it had just been replaced a few days before) and then when I replaced it again, this time with the correct oem bulb, eveything was back to normal. The guys on the Mercedes forum knew what the problem was right away.

[Q45tech]

Most alternators on vehicles are 3 phase [have 3 windings] which are connected after a retification diode in PARALLEL.

It is common for one or more of these diodes to fail first and the alternator to quasi function on 2 or even 1 coil [decreasing the peak capacity from 110 amperes to 60 amperes and finally 30 amperes]............before totally failing.

These diodes can open or short [adding ac pulses to the normal dc].

The diodes fail from overheating due to dirt blocking the alternator ventilation slots............lack of mainteance in keeping the alternator clean as brand new.

[burijon]

Is it safe to spray carb cleaner/throttle body directly on it? What about brake parts cleaner?

[lino]

tech:

How would you clean an alternator safely? My alternator is a year old now and I've been itching to have my engine cleaned and detailed, but I'm scared of getting an electrical problem with the high pressure water/ cleaning.

[mxr662]

Is it safe to spray carb cleaner/throttle body directly on it? What about brake parts cleaner?

Carb cleaner can melt plastic parts. I've done it.

Try this: http://www.crcindustries.com/a...8&S=N

Andy

[lino]

My mechanic has several bottles of that exact stuff on his shelf. I'll get one from him when I'm there next time.

[Q45tech]

Over the years several different trainee technican have caught Nissan and Lexus cars on fire with spray brake cleaners.................into a hot alternator.

High pressure air then Rinse pressure water works pretty well................but you have to do the sides and bottom [on a lift].

[DrewQ45]

usually your brake light will flash or stay dimly lit, the light brightens as the failure grows more imminent.

Replace with OEM unit. If you do the job yourself, you'll know why.

[Falkdesigns]

It must have been those non OE bulbs. I have a Denso alt IIRC, not sure if it's OE brand or not. The job on Y33 isn't that bad either. 2.5 years so far on mine.

[Q_SHIP]

Well, it turned out to be bad battery cables. Replaced those.

I brought my alternator to be tested and it tested perfect. I cleaned it up while I had it out.

The job was very easy in and out. Took me a total of an hour to pull it out and put it back in.