84 charging system problem
Thread Starter
Intermediate
Joined: Sep 2002
Posts: 34
Likes: 0
From: Columbus OH
84 charging system problem
I get about 13.8 to 14.8 charge and when i turn on all the lights and fan for heater the charge rate still shows the same , and also at idle the lights flicker, now shouldn't the rate of charge drop with all the lights on and fan ? and as the fan comes on at idle the engine drops down on rpm a bit at the fan start. my guess is a bad altinator, I know about the problems this year had and could a rebuild work here or should I just upgrade.?
Last edited by bwalker1947; Oct 31, 2008 at 07:07 PM. Reason: remove poll
Racer
Joined: Sep 2008
Posts: 456
Likes: 0
From: FL
You don't have any problem I think. RPM drops maybe you have bad idle speed motor (dirty throttle) 14.8 seems kind of high, not sure about that. 14.5 is probably OK.
Last edited by car5car; Oct 31, 2008 at 08:57 PM.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You don't have a problem, your system is operating the way it was designed to. Alternator cold, the output voltage is 14.7 volts (dash will read about 14.4 volts) and when it gets to its operating temperature the output voltage drops to 13.7 volts (dash voltmeter will read about 13.4 volts). The dash voltmeter reads voltage after the ignition switch whose contacts have about 0.3 volts across them dropping the dash reading by 0.3 volts. The voltage regulator attempts to maintain constant output voltage (affected though by the alternator temp). When the fan motor turns on, it momentarily draws about 28 amps (14 amps running) and this loads the engine because the alternator supplies this current). You don't need to do anything!
