When the engine is off the battery sits at about 11. When the engine is on battery is around 13.8, but ranging from 13.5 to 14. Now, when i turn my headlights on it drops under 10 high beams bring it lower. This is all at idle. When the motor is revved it goes back up to 13.5-14 until the engine goes back to idle. What is wrong? battery? voltage regulator in the alternator? Oh yeah 88 CRX Si with a b16 alternator was rebuilt about 3 years ago

 

mine does the same thing.. and i pretty much have the same setup(91 crx b16) but the volts dont drop as low as that when the lights are turned on.

a simple fix would to be just turn the idle screw up on the tb. thats what i have done and did help, just your idle is gonna be a little higher in nuetral.

 

ya its normal

 

mine does it too, d16a6, 88 Si w/ alternator new bout 4 yrs ago, always done it.

@ idle it sits 13.8 w/ nothing on.

drops to 13ish when the fan kicks in.
headlights go to a lil above 12v.
when the a/c is on i've seen it hit 10v (and then i quicky turned the damn ac off).

Sounds like a normal thing to most 88-91. I may just put new main grounds everywhere to help the alt / bat out, but thats it.

 

but the wideband A/F ratio changes when the lights go on A/F goes up to 16 sometimes more and starts detonating when lights go off A/F goes down to 12.5-13 for a bit until it settles aroung 14.5

 

try cleaning your IACV then.

 

i have a similar problem with your but mine doesnt drop to 12volts it sometimes drops 13.3 and the car starts shaking
https://www.homemadeturbo.com/forum/...?topic=48214.0
this is a similar post in the engine management section..
if you find it out the problem post it here cuz i gotta know too