Hello, I will try to be as detailed as possible. I drive a 1997 Honda Civic LX, manual transmission.

Three months ago I was driving in the rain and all of a sudden the check engine light went on and it had a rough idle, and the Check Engine Light kept fading in and out. It continued to drive for a few weeks and when I had the oil changed the mechanic informed me that I needed a new alternator. A few weeks later I spoke to a mechanic friend and he was surprised I was able to drive it for so long with the battery charging around 12.8V. So I purchased a remanufactured 75A alternator.

Shortly after I purchased the alternator, my car battery died while driving. I was able to get a jump and my battery charged right up and I drove back home. Two weeks after that the battery died again. I was finally able to get to my friend's shop where he installed the alternator. Unfortunately, when I drove away from the shop, the battery died. It turns out the battery fuse (under the hood) was blown, so we replaced it. I was able to drive home, but the car seemed to be in the same condition, with the Check Engine Light on. He tested the battery and it was running at 13.8V, which was much better than before.

Fortunately my car has been running, but I'm in the same state. Today I had the codes checked:

P0500 Vehicle Speed Sensor VEL/VEL1
P1298 Electric Load Detector Circuit High Input
P0135 Oxygen Sensor Heater Circuit Bank 1 Sensor 1
P0141 Oxygen Sensor Heater Circuit Bank 1 Sensor 2

I then checked the fuses under the driver's side dash and found the Alternator SP Sensor 7.5A fuse was blown. I replaced the fuse and didn't notice anything different.

A few hours later I got in my car and now, the battery light is dimly lit. Check engine light is still lit and car seems to be running the same. I used a multimeter and checked the battery without the air conditioning and it was running around 14V, but when I turned on the accessories and air conditioning, it was down to 12.8V.

Anyone have any idea what could be going on? I changed the upstream o2 sensor 8 months ago and it made a previous Check Engine Light go out for a little while. I also got a new battery 9 months ago.

Thanks in advance for your help!

 

If the fuse at the battery was blown you possibly may have other fuses blown i would check all fuses under the hood and inside car.

 

^Yes, and while you're doing that, check any wires for damage. Sounds like something is grounding out.