searched, Odd problems, need wiring diagrams for alt/speed sensor fuse

[drnenappes]

Im having a problem with my wifes 1998 civic LX, its bone stock and now the Alt/speed sensor fuse located in the under dash fuse box keeps blowing, Its fine when I first put it in, its fine at idle, but as soon as I start driving the car, the fuse blows, and the lights start to pulse and the car bucks when throttle is applied more than 1/4, also the speedometer does not work after the fuse blows, it just jumps up and down randomly. Ive started pulling wire loom off the alternator harness, I did find a broken wire and fixed it but it didnt do anything, I really need the wiring diagrams for this car, if anyone knows where to find them it would be a great help

Thanks

Ian

 

[custompainter]

i shouldn't help you seeing your a nissan 240 rocker but heres a link hope it helps Index of /downloads/tech/honda manuals/civic

 

[drnenappes]

hahaha, well Ive owned about 5 ef civics and CRXs, I switched to the 240 cause I wanted rwd and my wife still has her honda. I found a service manual for it last night, Ive done some troubleshooting, the fuse blows when the car is revved past 2500 rpm, if I rev it while its sitting, as soon as I get to 2500 the speedometer jumps to about 80 mph and holds there until I let it drop below 2500, if I unplug the alternator plug the fuse does not blow and the speedometer does not jump around, Im guessing that I either have a short somwhere on the alternator harness or the alternator has a short internaly, this one has really got me stumped and Im wondering if I should just get a new engine harness and or alternator, but we are rather short on money at the moment so I dont want to just go throwing cash away.

I really need your help guys
Thanks

Ian

 

[custompainter]

try pulling the plug on the speed sensor on the tranny and see what happens sometimes they get corroded and short out
pull it off and run the car and see if you blow that fuse if it still does get back to me i'm going to ask my buddy tomarrow and see what he says

 

[drnenappes]

pulling the plug on the speed sensor doesnt change anything, I have already tried that one, if I run it with the alternator plug off it runs perfect and everything works as it should except the speedometer, and the alternator, pulling the alternator plug is the only thing thus far that keeps the fuse from blowing as soon as the engine reaches 2500 rpms. Luckly my wife doesnt have to work until friday so I can have my car back and I think I may go to Honda tomorow to have a chat with one of thier service techs, but any more ideas would be greatly appriaciated

Thanks

Ian

 

[drnenappes]

Bump, the guys at Honda were as stumped as I am

 

[custompainter]

hey i see you havent had any luck yet neither have i my buddy has not clue either

 

[drnenappes]

well after talking to an online honda mechanic Im leaning more towards voltage regulator, looks like I will be picking up an alternator tomorow

 

[kaoskustoms]

please have the alt tested before you buy a new one. any auto parts store should be able to test it for free. if you do find that it is ok pull the harness of the engine and take the loom apart and look for a short. should only take about 10 min to pull the harness off.

 

[drnenappes]

I had planned on testing the alternator, and I did, it tested out fine, I started pulling the harness off earlyer, but my buddy showed up to put new spark plugs in his wrx, so we did that, and when I we went to test drive it he blew his tranny, so now I get to split my efforts between the 2 cars, I should finish tearing the harness apart tonight, anymore ideas would be great though

 

[drnenappes]

well I went to a differant honda dealer, and the parts guy recognized my problem right away, there was a TSB on the issue a few years ago, the same thing was happening a lot to this model civec, there is a large test plug under the intake manifold, I had already had the whole harness apart looking for shorts and hadnt found any, well there did happen to be one less than half an inch from the plug, one of the wires had its coating scraped off in a small spot, but in removing the harness I had gotten it all dirty so I couldnt see that little spot, hopefully that is the only one Im going to go over the harness again just for good measure, then Im going to put everything back together. wish me good luck.

 

[drnenappes]

problem solved, thanks for the help guys

 

[custompainter]

right on