Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
|
11-19-2013, 10:51 PM | #1 |
not enough hours in the day
Join Date: Jan 2009
Location: Axtell, NE
Posts: 550
|
Alternator problem, won't charge at higher rpms
Has anyone had an alternator that charges fine at idle, but not at highway speeds? I haven't had one act this way, and am trying to narrow down the cause before tearing into anything.
__________________
65 K-10 Short Step 68 C-50 70 K-5 85 K-10 & piles of spare parts |
11-19-2013, 11:03 PM | #2 |
Registered User
Join Date: Oct 2003
Location: OC CA
Posts: 1,374
|
Re: Alternator problem, won't charge at higher rpms
How about a bit more information:
1) Alternator model: 10DN, 10SI, 12SI, CS130??? 2) Voltage at idle. 3) Voltage at 1200 RPM 4) Voltage at highway RPM (2000+ RPM) Can you measure charge current from alternator? - this requires either a shunt resistor or clamp ammeter. //RF
__________________
"The Beast" 1975 Chevrolet C20 longbed 350/700R4! with 3inch body lift Dual Flowmasters Super 40's! TBI retrofit completed (2007-07-29) New 383CID (+030) 08-304-8 9.5:1CR x36,005 (2012-12-17) |
11-19-2013, 11:26 PM | #3 | |
not enough hours in the day
Join Date: Jan 2009
Location: Axtell, NE
Posts: 550
|
Re: Alternator problem, won't charge at higher rpms
Quote:
I just drove 20 miles with the headlights on without dropping below 12.5 volts so I'm assuming that the alternator is charging some. I don't have a clamp ammeter, but may be able to get one tomorrow to check the current, right now I'm just working off voltage at the battery.
__________________
65 K-10 Short Step 68 C-50 70 K-5 85 K-10 & piles of spare parts |
|
11-20-2013, 12:41 AM | #4 |
Registered User
Join Date: Oct 2005
Location: North Idaho
Posts: 335
|
Re: Alternator problem, won't charge at higher rpms
YES - this recently happened to me with my 1980 Suburban this summer. I started a thread over in the Electrical Forum here and was given much help:
http://67-72chevytrucks.com/vboard/s...d.php?t=598561 The short answer is: the belt was slipping and I didn't immediately recognize the problem because there was no squeal. Please read the whole thread, because I tried a few cures before settling on one that actually worked. Some of the intermediate steps I took may work for you. Please let us know what helped
__________________
1980 K10 Suburban Silverado, original 350 w/Qjet swapped to 406sb, TH350C swapped to TH400/205 |
11-20-2013, 06:42 PM | #5 | |
not enough hours in the day
Join Date: Jan 2009
Location: Axtell, NE
Posts: 550
|
Re: Alternator problem, won't charge at higher rpms
Quote:
Thanks for the info, sometimes it is the simplest solution.
__________________
65 K-10 Short Step 68 C-50 70 K-5 85 K-10 & piles of spare parts |
|
Bookmarks |
Thread Tools | |
Display Modes | |
|
|