in my civic, on the highway, going to work this morning, about half way there, my CEL comes on and the speed-o starts going back and forth like crazy, so i pullover, pop the hood, no visible problems, engine temp is normal, so i head to work. get there, try to get the CEL codes, and come up with 20, 41, and 65. talk to some people and get opinions, a friend comes and looks, say it's the alternator. then after my shift ends, i bring it to the mechanics at work, and they say the alternator and battery are both bad. anyone one else have any expierence with this, and have advice ?

 

so silent...

 

Well, take the car to autozone and get the battery and alternator tested. is their a lot of corosion on the battery terminals?

 

that's what i did (work = pepboys). the battery came up as bad, it holds charge, but barely. and i didnt take off the alternator to put it on the machine. but that seems to be going too (the charge it's putting out isnt steady at all). i was just wondering if anyone knew any other causes, besides the battery and alternator.

 

20 is the Electrical Load Detector or ELD. It's built into the fuse box.

41 and 65 are the primary and secondary O2 heaters.

Before replacing the alternator or battery, I would check the alternator/VSS fuse under the dash. I went through 3 batteries and 2 alternators when I had a similar problem. My alternator wouldn't charge my battery and eventually the battery would die. My speedometer also worked spradically. After swapping batteries and alternators, I checked all the fuses, and the VSS/ALT fuse under the dash wash out. Replaced that, and everything was gravy. If there's noting wrong with your O2's and your VSS/ALT fuse is out, replace it and reset your ECM. Your problems should go away.

 

that sounds like a strong possiblity, thanks inspyral. i hope it works, replacing the alternator was the last thing i want to do.

 

Inspyral sounds like he's right. The only other thing I would think of checking would be the plug on the top of your tranny. It's for the speed sensor. It has 3 wires coming out of it. If that has wiggled loose, it may be contributing to your problem.

 

i replaced the fuse, and everything was fine. and then 2 minutes later the fuse popped again.

 

Have you done any electrical work to the car recently?

 

nope, not in quite a while