Drewster67

Hello All -

Ive got a Autozone Duralast 49D Battery - Cranking amps at 32 Degrees C = 1000. Cold Cranking Amps at 32 Degrees C = 750.

Under a Full Load - I.E. All driving Lights on, HVAC Blower running,Pioneer 45x4W Tuner On, Electric Fan Running - the Volt meter reads 12 Bar. Without a load - she reads between 14 and 16 Bar (electrical redline) on a constant basis.

Is this something I need ot worry about?. what Ive been doing, to drop the load, during the daytime is turning my running lights on. I'm concerned that this may be a bigger problem than I realize and I'm also afraid of burning something out.

My S2 is running rather well except for an occasional backfire in the intake manifold which I believe is due to tired cap and rotors (Speculation) & (Soon to be replaced) - Any suggestions regarding that matter as well?. New Wires, New Plugs & Timing is Accurate.

Any Information regarding these two matters would be greatly appreciated.

Drewster67

Okay - I type before I think. My Bad

Cold Cranking Amps = 750

jpitman2

Before I worry too much about that reading, I would check it with a DVM at the battery, or the hot post in the engine bay. Mine occasionally does high readings like this, so I put a meter on the cigar lighter socket. I got steady high 13V to low 14s (eg 13.8-14.3 range). The fluctuations are a sign of bad contacts on the meter, not a sign of an alternator problem in my case. Suggest you check in same way. If you do have real high Voltages, then check the alternator.
jp

Normy

I'd do what JP says....but be advised: A failed voltage regulator can cause this, destroying a perfectly good battery and possibly more. Stereo equipment, relays, and computers can be harmed by high voltage. I've heard that rough running can be caused on occasion by an alternator that produces excessive voltage...upsetting the LH and EZK computers!

The electrical system on our cars involves a 12 volt battery and a 13.8 volt alternator/voltage regulator.

Normy!
[Stuck in Asheville because the flights are FULL!]

Old & New

Minor points;

Some regulators are 14V.

A bar is ~20 psi

Drewster67

Thanks You Gents for the feedback.

Are there any physical markings on the regulator to verify between 12 or 14 V? What is the normal regulator amount?.

I'm almost too embarrassed to ask but where is the regulator?. Is it built into the alternator?.

I would like to do a physical inspection prior to having the alternator tested.

Thanks Again

Old & New

Drew,

The regulator is built in to the alternator, at least on the Bosch and Paris-Rhone. I have seen them labeled (14V).

Chris

When I got my alternator refurbished it came with an adjustable Voltage Regualtor, just FYI.

Chris

Drewster67

Otay - (as Buckwheat use to say)
and Thank You!.

Just to clarify one thing -

*Question*

If in fact my alternator is 14v - Without a load, Should my Volt Meter should be at the 14 Bar?.

<img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />

Randy V

Drew, do you mean the 14 V 'mark' on the voltmeter?

As the anonymous Old & New pointed out, 'Bar' is a unit of pressure.

Drewster67

I guess you can teach an old dog a new trick -

I did not know that - I was just referring to the actual "bar" on the gauge/meter itself.

Thanks for schooling me! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Drewster67

and yes - the actual 14 "mark" on the gauge -

Boy do I feel silly

Steve Cattaneo

The charging output of an alternator is always check under a load, all accessories on, car running. Check the voltage at the battery. Over 14.8V is an over charging alternator. Bad regulator <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Incendier

Per Normy above, 13.8V should be the regulated output, and given the inaccuracy of the gauge, a reading appearing to be 14V is normal. +/- 12.6V should be open circuit battery voltage.

To be sure, throw your DVOM on the beast and see what the actual output is. Exceeding 14V + a few decimals is quite hazardous to your electronics and your battery, and much less will eventually leave you stranded.

Drewster67

tHANK yOU GENTLEMEN - I'm going to have it tested right now. I'll post the outcome shortly.