Car...

98 Acura Integra
(OBD2)
OBD2 to OBD1 Jumper with OBD1 P28

Problem...

My voltage cuts in/out. Like my alternator stops working. I watch my volt gauge and it will be at like 13.9. Then randomly go down to like 12.5 and my lights will dim and ****. If I rev it up to like 4krpm it'll go back up to 13.9. And if im driving above 3500ish rpm it's fine. But anything below that im at 12.5ish.

Things I tried...
-Swapped Alternator
-Checked Fuses
-Check engine grounds
-Swapped Ecu's
-new Baterry

I'm clueless now. ***** driving me insane. Sometimes it's normal or will randomly do it for like 2 seconds. But earlier today before I swapped alternators and after tonight. it's been doing it constant.


...All I want for Christmas is my honda fixed...Lol

 

Mine used to do that bad, if i let the engine decel itself while i was in gear, all the lights would dim and i'd drop down to about 12.5 volts. then when i got back onto the throttle it'd jump to around 14.0.

 

Mine will do it while driving and idling. Anything below 4k rpm it'll drop down till i rev the motor to like 4k rpm then it'll go back to 14. Idk whats wrong with it. I drove it this morning and it's fine. But if i keep driving it it'll start doing it again. It's weird.

 

Are you having any problem with the battery going low on charge? My guess is it's normal operation of the ecu adjusting the output of the alternator based on input from the ELD. We start getting complaints about the lights dimming around this time of year when it gets dark out earlier. It's normal.

 

No. I swapped my battery out. Tried differ ecu's. My whole car stops getting charge from the alternator. As if the alternator went bad until I rev it past 4k rpms. The problem I am having is not normal at all. It's not like it's from the cold weather causing my battery to get lower volts/When I hit the brakes the lights dim. Thats normal I know. But mine is actual cutting out. If I don't rev it past 4k it will run on the battery until the battery voltage gets so low the car turns off.

I was told that the ELD is in my engine bay fuse box and to replace the fuse box and it should fix the problem...Does that make sense? Im hoping so. Because It'll be a quick simple fix.

 

Sounds to me like an ELD problem, or maybe just a loose alt. fuse or connections. 94

 

Is the ELD Built in to the engine bay fuse box? Because I am being told by some people that it's in the fuse box and by others that it's in the ecu. i am under the assumption that OBD2 is in the engine bay fuse box. And that obd1 uses it in the ecu. I checked all the connections and everything is good.

 

The ELD is mounted to the underside of the engine bay fuse box on 94-98 Integras, [USDM only, CDM Integras do not have am ELD].

You should check fuse 42 - 40A and fuse 41 - 100A, [both hot at all times] in engine bay fuse box, make sure these fuses are securely screwed down. 94

 

I checked all the fuses and made sure all of em were tight. It's weird because it only does it sometimes. It's driving me crazy trying to figure out the problem.

 

I am having the same problem in my civic (96 dx hatch) only worse. I have a b18a1 swap with a p75-a01 obd1 ecu but I'm using the alternator from the d series because my harness was Frankensteined by the previous owner. When I bought the car the alternator was pretty much bad but it charged the battery enough to get the car started and running. when I pulled the motor and did a wire tuck I replaced the alternator (still using the obd2 alt) and it worked fine, charged at 14 volts at idle with most of the electronics off and and 14 volts while driving. when I turn on the lights or hit the blinker it would drop and come back up with the draw of power (normal?) Now, out of nowhere, the alternator just stopped working entirely, it is not charging at all, the only voltage I am getting is from the battery, when the battery dies the car dies. Any ideas or is it just a defective alternator? (sorry for the long post)

 

Check the black/yellow lead at the alt., it should be 12V+ - 12.5V+ when ign switch is on, fuse 15 - 7.5A, [hot in run and start] in under dash fuse box.

Do not just check the fuse, make sure there is power on the black/yellow at the alt. when ign. switch is on.


The same goes for the OP, check for power on the black/yellow at the alt., fuse 24 - 15A - 20A, [hot in run and start] in under dash fuse box.

Because your problem is intermittent, you will need to connect a "telltale" to the black/yellow lead at the alt., wire a 12V light to thew black/yellow and run it into the car where you can see it, if the light goes out when alt. stops charging, you have found your problem. 94

 

It was a bad alternator, I made the mistake of installing it with a dead battery. I do, however, think that the d series alternator is not strong enough for the b18, it charges at 14 volts when im on the throttle but when i am stopped, it drops to around 12 volts. I'm considering a b20 alternator when I have the money.

 

I will try that as soon as the snow goes away. Thanks for helping!