My Alt is taking about 30-45 seconds to start charging around 15. It holds around 9-10 until the truck runs for a almost a minute. It only happens on cold starts. Normal?Alt taking its time
- Thread starter Kartmnn
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My Alt is taking about 30-45 seconds to start charging around 15. It holds around 9-10 until the truck runs for a almost a minute. It only happens on cold starts. Normal?
That sounds normal, but I think it should hold around 11-12 for the first 30-60 seconds. My truck does the same thing (well, at 12 volts) until the glow plugs turn off, then it smoothly runs the voltage up to 14 for the rest of the trip.
If yours is staying down below 10 volts, your batteries might be weak. Or they could be fine, but many places test them for free, so you might want to check.
If yours is staying down below 10 volts, your batteries might be weak. Or they could be fine, but many places test them for free, so you might want to check.
Depending on year the volt meter will read slightly different. 01-02 trucks read closer to actual than the 03+ trucks do I believe. I know my 01 clusater showed actual battery voltage, but all of teh newer trucks I've seen tended to not drop much below 12 unless teh alternator is out completely. And with a 105 amp factory alternator, I could see 9 volts with the 115 amps of glow plugs and 45 amps of intake heater if it's an LB7/LLY. I know teh LBZ's use slightly more current, but there glow plugs run for a fraction of teh time of the earlier trucks although they do have a bigger grid heater in them. Even with my 130 amp AD244 alternator I still will only hold about 10 volts with both the glow plugs and intake heater going.
Aah, good to know. I wondered about that, given that my coolant temp gauge is (apparently intentionally) wrong.
LLY's dont have a grid heater. And LLY's have the same fast-heat 4.7volt glow plugs with a "smart glow plug controller" system that the LBZ/LMM/LML trucks do.
Even at 0* my glow plug light (05 LLY) isnt on for much longer than 3 seconds. Compared to an LB7 where you have to wait 3-4 times as long for the glow plugs to heat up in the severe cold.
I call all the intake heaters a grid heater, force of habit after working on CUMMINS for so long. I haven't messed with an LLY in cold temps, so I don't have first hand experience with how long they glow for. I know the tuning calls for 8 seconds at 90, so I figured they were like the LB7 plugs as that is about what they call for. And I had seen several sites listing the same glow plugs for the LB7 and LLY, http://www.accuratediesel.com/shop/190.html .I know I cut my glow plugs down to less than half in my LB7, and it still starts smoke free all the way down to freezing. Below freezing I still run stock glow time which isn't that much compared to some other diesels like my old 6.5.
Didn't know that. I guess I made a false ASSumption that it had one since the LB7 and LBz had em.
Has anyone determined the relationship between the dash lamp, and actual GP energy? I question if the glow plugs are still on after the light goes out.
are you serious? You cant figure this out for yourself? With all the genius research you do on duramax's?
x2. I've never seen mine on for more than 2 seconds.
I thought the grid/intake heater started on the lbz.... lly/lb7 didn't have them???
The LB7's have a small intake heater that threads into the intake just before the Y bridge. It is often removed and a 5.9L CUMMINS drain plug put in it's place as they are the same thread. It is a small heater, only about 550 watts that runs for up to 3 minutes on a cold start. I know when I was up in the snow at 8 degrees out it ran for awhile as I had to wait for it to go off before the ECM would allow the fast idle to come in.