I have a 97 ex with a b18c from japan. I have some type of a charging problem. My grounds are all good. I had the alternator checked at advanced. They said it was ok. When I put it back on the car however I still only have 12.xx volts. When I should have 14 or so. The connections are all clean. What is my problem. THx in advance.

 

Alternator 'C' wire is used by the ECU to shut off the alternator. Make sure it's not getting shorted to ground - that'll shut off the alternator.

Then check all the connections again. What's the battery voltage when the engine's not running? Try another voltmeter, I've seen some that are that far off.

 

Ok, I'm not exactly sure where the 'c' wire is but I"ll look. I checked the plugs on the back of the ecu. Everything seemed fine. It's a major pain to trace those wires becuase they are all under the intake manifold and around the oil filter etc. The battery voltage not running is like 12.5x. Running it is like 12.2. I think the volt meter is fine.

 

if you rev the car does the voltage change?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gents97civ &raquo;</TD></TR><TR><TD CLASS="quote">Ok, I'm not exactly sure where the 'c' wire is but I"ll look.</TD></TR></TABLE>It might be white/yellow, but I'm not sure if they used the same color for different years?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ShafftsTeg &raquo;</TD></TR><TR><TD CLASS="quote">if you rev the car does the voltage change?</TD></TR></TABLE>Yeah, check that. Part of the control philosophy is shutting down the alternator at idle if the battery's charged up & no big loads are turned on. Turn on the lights, ventilation blower, window defogger, stereo, etc, & see if it changes.

 

It was short. I got it fixed. Thanks for the help. I hope nobody else has problems like this cuz they are a pain to track down.

 

where exactly was the short cuz I have the same problems with my teggy.

 

i have an 89 civic si. with stock d16a6. anyways. i was leaving the shop today and the battery light came on so i was like ok this is weird. i went to advance to get one of those free battery checks.he said battery was putting out 13.xx volts and he said that he would check my alternator when he checked it was only putting out 8.xx amps when it is supposed to be closer to 50. The alternator he said was good but the machine said to check wire (output or input) cant remember. what is the easiest way to go about fixing this.