SC Charging Specs?

ohecht · 11-10-2002, 03:06 PM

I've been having some weird, very minor, and sporatic electrical issues lately. Nothing major, just things like the volume of the CD seeming to fade (might have been the disk, I switched and it seemed to go away. Power windows seem slow, etc. No starting problems or gauge jumping at all (like when my alternator went out one year ago)

I checked the voltage at the battery, and it was 13.29 with the care idling, 13.32 with it at 1500 rpms, and 13.34 with it at 3000 rpms.

The spec is 13.5 - 14.2 volts at 1500 rpms according to the Bentley manual. It is close to spec, but it seems bad that the voltage would change so slightly with the RPMs. Could that be just a loose belt? I hope it's not the regulator or alternator.

Thanks,

Olivier

Superman · 11-10-2002, 03:34 PM

Make sure your belt is tight enough, but I doubt that is the problem. 13.3 volts is enough to allow your electrical system to limp along, starting the car, etc, but it will not be enough to keep the system 'robust.' Good, healthy charging systems make 14.5 volts with no electrical 'users,' and only a little less with users. I mean, with headlights on, stereo on, rear defroster on, A/C on, voltage should still be 13.5. Try turning these things on and see if voltage falls below 13, with the engine running. Also, look for a fluctuating voltage. It should be steady.

If your alternator needs rebuilding, you can have it done for around $100 or a little more.

john walker's workshop · 11-10-2002, 03:34 PM

crusty battery connections and poor grounds will cause the charging voltage to be low, as well as the regulator.

ohecht · 11-10-2002, 04:29 PM

I will check those things...I would hate to have an alternator that was new a year ago rebuilt already.

I think that one was a Valeo...is there a replacement that is more reliable and maybe has a higher output?

Olivier

Superman · 11-10-2002, 04:45 PM

JW makes a good point. the next step would be to clean all relevent electrical connections within in an inch of their lives. Battery posts and cables. Engine and body grounds. After that, you can draw conclusions about the alternator. If voltage is still low, then perhaps the voltage regulator is all that's wrong. I'm not familiar with your particular alternator, but it probably is capable of making plenty of power.

ohecht · 11-10-2002, 05:51 PM

I have been meaning to do that for a while...the parts were ordered a few days ago coincidentally, so I will definitely replace them all.

Olivier