Diesels need more electric?

[thechevyhdman]

Theres been alot of talk on what peoples voltage meters are running at in their Dmax trucks, and I was wondering this. We have two trucks a Dmax and a 6.0 gasser. Both identical except engine/tranny(both with same rated alternators and both with dual batterys) the gasser runs perfectly between 14 and 18v basically steady at 16 volts. But the Dmax never goes above 14 volts. Is the reasoning of this more electronics in the Dmax or another variable? Bill.....Just Wondering

[DmaxMaverick]

After cold start draws (glow plugs, intake heater), the Duramax should not draw any more current than a gasser, all else being equal.

The difference you see is probably just GM's notoriously inconsistent instruments or a manufacturer's variance in the components used in the circuit.

Or.....

The voltage regulator on newer GM vehicles is controlled by the ECM. Early Duramax vehicles were charging at a lower rate than later models, or models that had a programming update. When new, mine charged at about 14 volts (truck was built in Oct. 2000). Now, after the update, it charges over 15. I'm not sure when the update was made available. I would also suspect that idle/cruising RPM's may have something to do with it, but is supposed to be compensated by the pulley size. There was/is issues with a voltage dip, causing dimming headlights, with a throttle release to idle. I believe that was the reason for the voltage increase with the update.

Outside any of this, I don't have a clue. Cheers

[K1XV]

If it was really 16v. your battery would be fried. I think 15v. or more would be cause for major concern. Low 14 volt range in summer, mid to high 14 volts in winter would be fine.

I have an old Mercedes that seldom gets above 13.9 volts and it does fine, and batteries (I have 2 batteries installed due to lots of radio equipment in car) seem to last fine.

Use your volt meter to track trends, not as an absolute instrument.

Ray

[a64pilot]

"Use your volt meter to track trends, not as an absolute instrument."

K1XV,
I agree absolutely, I believe this goes for all the stock instrumentation. If you want accurate instrumentation buy SPA or other quality instrumentation. IMHO stock is good enough for our purposes

[pinehill]

I believe that the Dmax pulls considerably more power from an electrical system than a gasser by way of the power required to operate the injectors. Even though the gasser has an ignition system which the diesel does not have, no manufacturer that I know of has found it necessary to cool a gasser ignition system with liquid the way our injector electronic drivers are cooled with fuel.