Alright so I have a 1990 Accord,

A month ago I was driving home from work and I noticed I started to loss interior power. Lights started dimming out, RPM gauge was fluttering up and down. Parked the car when I got home shut it off and tried to start it, it wouldn't turn over didn't even click. The next day when I got in the car to open the hood I noticed my seat belt latch was moving correctly when the day before it lagged.

I attempted to turn it over and it started right up, started driving to work and about ten miles later it started sputtering and backfiring once the RPM's hit over 2K. Sounded like it was miss firing or something. Limped it to work and parked it, tried to turn it over and nothing. After work I turned it over and it started right up. But by the time I got home it lost all power, interior and motor.

I pulled the alternator out and when I went to get a replacement they suggested they test it before I purchased one. It passed all tests they ran and was sitting at around 14ish amps.

I put it back in my car and for the next two weeks it ran just fine.

On my way home one day I didn't even make it five miles before it lost interior power and then died completely on the side of the road. Got a jump start and it started right up and drove it home and parked it.

Yesterday I tested the power from the battery while running it was at around 8, alternator was about 8. Changed out the 80 battery fuse and the terminals on the positive and negative.

It was back firing while parked when I turned the throttle cable. If I turned the headlights on the car would die completely.

After it died it wouldn't start so I beat the alternator a little with a hammer and bump started it in reverse. Once it started up I had full interior power and the car didn't back fire. Tested the power at the battery and alternator and it was roughly 14.

Pulled the alternator out and again and had it replaced.

Left the battery on low charge over night and on my way to work half way it lost interior power and headlight dimmed out then it started backfiring. Had to drive the rest of the way to work with no headlights on the prevent the car from cutting out completely. Got to work, parked it and it wouldn't turn over. No interior power at all. I just pulled the battery out at work to charge it and when I got in the car it turned over just fine.

So now I'm kinda lost. I'm gonna bring the battery in to get it tested. But shouldn't the car be running off the alternator power while it's running and only pulling from the battery to start up?

Any help would be grateful.

Thanks

 

Check the wiring harness that goes to the alternator, look for pinched or bare wires that might occasionally short to ground.

There's a "control" wire in that bundle that can shut down (or maybe reduce) the alternator capacity. Maybe labeled "C" at the alternator? If the voltage is good and the ELD isn't measuring loads, the computer can shut off the alternator to improve fuel economy.

So if that "C" wire is pinched or shorting to ground, it can shut off the alternator when it shouldn't be shut off.

HOWEVER, the part that doesn't fit is that it's OK & starts up after being parked for awhile. Otherwise, a shorted "C" wire should act like the alternator doesn't work. The battery would still be dead after being parked & cooled off.

 

When I changed the alternator I noticed the plug had some build up on it, not corrosion though, I'll take a copper brush to it and clean it off and check out the wires running into the harness.

Could I have a short some where that could be draining power?

When I bought the car it was wired for a system, amp, sub, and deck. But when the stereo was on I could hear static noise like it had a bad ground. So I disconnected the deck and when I replaced the terminals I made sure to leave everything that wasn't required out of the positive and negative terminals.

I've owned the car for over a year and hadn't had any issues with power loss until just recently. The first time I noticed it was after poor weather and it's been relatively cold since then. Around 30-40 highs.

On the battery the CCA is 550, is that enough for temperature around 15-40?

Only thing that I can remember happening before this issue was the cigarette light port. I pulled the drink tray out and the port came with it. Could that becoming in contact with something causing it to short out as well?

 

A short that drains power doesn't quite fit the symptoms. Particularly how the battery is strong again after being parked for awhile. Actually that's the symptom that makes this unusual.

A short in the alternator "C" wire doesn't drain power, but it just shuts down the alternator. Still doesn't fit with the battery coming back to life after being parked.

If it was wired for an audio system, do you think it might have any remaining creative wiring for an alarm or anything else?

 

When I took the alternator out the first time I was looking for the interior fuse box. On the driver sides they had a car alarm system hooked up. Which I didn't know about. It had power running to it but I clipped the wires and tied it off. That was when it ran for a few weeks before acting up.

It also was wired for fog lights.

When I get home I'm gonna follow the wires that were leading into it and look for where the tapped in for power.

I work with the guy I bought the car from originally.

He said once every year or so he had to change the O2 sensor cause the car would leak oil from the motor and it would cause issues (backfiring)

Could that be it?

I get how it could cause the backfire / sputtering but the loss of interior power and it not turning over after it dies I don't get.

Maybe it's restricting the motor from getting the power it needs to run the alternator?

Edit
So when I reinstalled the battery I had charging while I was work I pulled the harness off the alternator and cleaned the plug with a brass brush, got all the build up off and connected back together. I was lookin for any damage on the wire harness and it all looks good. I didn't see a wire labeled C, there was four wires. Two yellow and green, one yellow and black and yellow and red.

 

Sorry for the double post but figured I'd bump this.

I charged the battery all day and after leaving work made it a few miles before it started with the same issue again, ended up parking the car and pulling the battery.

Took the battery to Orielys and they tested it. Said it was good just needed a charge so they are charging it right now.

Is there a fuse for the alternator?


That's something I haven't checked.

If the vehicle is running and I pull either terminal off the car dies. Could the car be running off the battery if the alternator had a blown fuse? Hence the alternator not charging or running the car?

 

Sounds like an issue with the ELD unit.

 

If under-dash Fuse No. 2 (15A) was blown or there was an issue with the Blk/Yel wire (which is the Ignition (IG) wire going to the alternator), then the alternator won't charge. Fuse No. 2 and the IG wire supplies the ignition input that turns on the alternator/regulator assembly.

However, it doesn't sound like the Fuse No. 2 is blown, as the same fuse protects and provides power/voltage via other Blk/Yel wires for the PGM-FI, ELD, gauges, emission control, automatic transmission and engine control mount. If the fuse was blown, you would have other issues with these other components.

It can be possibly be an issue with the Blk/Yel wire to the alternator. There is also a Blk/Yel wire from under-dash Fuse No. 2 that goes to the ELD (located at the under-hood fuse box).

Here is some general info. on Honda's charging system:
Honda's utilizes a dual mode charging system to increase fuel efficiency and reduce drag on the engine on start-up. The ECU determines charging based on info. from the Electronic Load Detector (ELD). During heavy load, the ECU can set charging voltage for high output (~14V - 15V). During light load and start-up, the ECU sets charging voltage for low output (~12 - 13V). The ECU can control charge modes (high or low output).

The ECU will not shut off the alternator.

You can read more about Honda's dual mode charging system here:
Honda's dual mode charging system

 

When I get off work today I'll follow those wires from the fuse box and see if there is any issue.

After having my battery charged from Oriely I was able to put it back in the car and drive it the rest of the way home. I tested the battery on / off and it was 11.46, tested the alternator on and off and it was 11.46. Ran out of day light to follow any wires so it'll have to get done today. I was able to follow the harness from the alternator that looks like it leaded to the timing chain? On the drivers side of the motor then splits and has a wire running to the fuel line.

This morning I went out and started the car up to take it to work, it had a rough start took a few seconds >5. Was also roughly 15° out. Once it started up the battery light came on, then dimmed out and off. Car still had headlight and interior power.

After pulling out of the driveway I made it about a half mile before the battery light came on and it dimmed out and lost all power.

Even though the battery tested good could I still have a bad cell that would pass it as good?

I noticed last night that the belt on the alternator was loose. Wasn't as tight as the rest of the belts and I could flex it either way push/pull.

When the car is running there is a squealing noise not too loud like a bad belt just something noticeable, from where the alternator is but I assumed it was the power steering pump after disconnecting it twice it lost some fluid. Could my belt not be tight enough causing it to not spin the alternator fast enough or slip on the pulley?

Car has new tires, starter, alternator, and over 354K miles.

Runs like a champ except with this electrical problem. I would hate to have to retire the car when the cost doesn't beat the value.

 

Imo, the battery probably is bad. Generally, a resting battery should be about 12.6 volts (6 cells @ ~ 2.1 volts each).