Ping Estang

Strega · 07-18-2005, 04:50 AM

I think I remeber you saying you had to have your alternator replaced. What were the symptoms? My battery charge light in the dash has always been on when I start but would go out after I revved it up. Now My batteries stay about 11.5 volts unless I run the generator along with the engine and the battery light in the dash stays on. When I checked the voltage at the alternator it is 12.5 volts with the engine running. I think it should be around 13 to 14 volts?

thanks, Brian

Strega · 07-18-2005, 04:50 AM

I think I remeber you saying you had to have your alternator replaced. What were the symptoms? My battery charge light in the dash has always been on when I start but would go out after I revved it up. Now My batteries stay about 11.5 volts unless I run the generator along with the engine and the battery light in the dash stays on. When I checked the voltage at the alternator it is 12.5 volts with the engine running. I think it should be around 13 to 14 volts?

thanks, Brian

dirko · 07-18-2005, 09:30 AM

Hi Ho: As with any battery/charging system you need to isolate the problem. A shorted cell in the battery could cause the low voltage (lots of current would flow). The real measure of an alternator is whether it will put current into the battery. The voltage is determined more by the condition of the battery. You could also have a problem with the voltage regulator (which may or may not be combined with the alternator). An easy approach is to change batteries to a known good battery and measure the voltage across the battery during charge conditions. It should be about 13.8 volts.

ESTANG · 07-19-2005, 07:13 AM

HI BRIAN
I HAVE NOT HAD ANY ALTERNATOR PROBLEMS. GOOD NUMBERS FOR A PROPERLY OPERATING CHARGING SYSTEM IS LIKE DIRK STATED SOMEWHERE BETWEEN 13.5-14.2 VOLTS. IF YOU CAN FIND SOMEONE WITH A BATTERY/ALTERNATOR TESTER YOU COULD LOADTEST THE BATTERIES TO VERIFY THEIR CONDITION,THEN CHECK FOR THE PROPER ALTERNATOR AMPERAGE OUTPUT(SHOULD BE WITHIN 85% OF RATING, EG.100 AMP ALTERNATOR SHOULD PUT OUT A MINIMUM OF 85 AMPS)
HOPE THIS HELPS. GOOD LUCK.
EDDIE

Strega · 07-19-2005, 07:40 AM

Thanks! I put in new batteries and can charge them with a charger or run the generator and they check at 13.2 if I take a trip or leave it set a long time they drop to about 11.2 and the charge light comes on in the dash. At that voltage my slides won't work either. I don't think the alternator is charging enough to keep up when running. I am going to put in a master disconnect switch on the chassis batteries also because I think I have a slow draw on them somewhere. Both batteries are always equal voltage even if I disconnect the jumper between them so I'm pretty sure they are OK. I have a 130 amp alternator and don't have a way to check amperage output but my voltage meter showed 12.5 at the + terminal on the alternator when running.

To that end I have an inside on these and am going to try a new one on Thursday since I won't be out anything if it doesn't work. I will let you know what I find.

dirko · 07-20-2005, 04:07 PM

Hi Ho: Since you seem to have a good voltmeter, current can be checked roughly by measuring the voltage drop across the wire from the alternator. If, for example, it is 6 AWG, there is approximately 0.4 ohms/1000 feet or 0.004 ohms/10 feet. If you have 100 amps flowing there is 0.4 volt drop across the cable. Not too hard to get a quick check if you have a sensitive voltmeter.

Strega · 07-21-2005, 12:28 PM

Ok Dirk thanks!!! New alternator came in today so I may put it on tonight not sure it's about 98 degrees here and the dew point is 70+ so the feels like is around 108+. After changing clothes 3 times today already ( our shop isn't air conditioned) I may not feel like fooling with it. I'll post what I find when finished.

Strega · 07-22-2005, 04:01 AM

Alternator was the problem!

dirko · 07-22-2005, 07:44 AM

Hi Ho: Good, glad you got it fixed.