speedometer acting crazy

[JDM00CivicEX]

my alternator gave up on my 2000 Civic EX Coupe so i installed a new one and i also put in a new battery today, now when im driving, my speedometer goes crazy, like it will jump to 120 MPH then go back to 0 MPH and so forth and it does not show me the right speed that im actually going at, so does anyone know how to fix it or know wut might be the problem??? thanx

[crxlvr]

does this happen when you are driving, or at idle?

[JDM00CivicEX]

sometimes at idle it will jump, but this mostly happens when im driving.

[TheRebirth]

lol, get your buddies to ride in it

"HEY GUYS! LOOK! 0-100 in 3 SECONDS! w00t!"

[SiRII]

i got that problem too. except when i hit 50 mph. it jumps to 80 mph.

[tEk4000]

its probably your speed sensor, this is located on top of your transmission, it's quite expensive, 200~250 or so. good luck

[Marc-OS]

check your ground connections.

[Drift King]

I think it might be an electrical problem. Im not sure but I think your spedo works like the tach, different voltage for changes. Therefore you might have to recheck your instal, bat., ect. If that doesnt work you might want to check with a professional. Who knows what other stuff may be going wrong that you cant see.

[crxlvr]

also check your TPS and the idle speed sensors.

[wagsaccordsir]

Check your the connection on your alternator, ennsure that it is tight. Pull the rubber grommets back and wiggle the wire, if it moves tighten it.. This may or may not fix your problem, but this same thing happened to me on the way to a show yesterday. It was almost as if I had went through an electro magnetic shield.. LOL Gauges went haywire, stereo flickered, everything just went crazy as if they had a mind of their own. I got out and checked my battery terminals, they were tight. I then grabbed the wire that goes from the alternator, over the valve cover and to the back of the block. When I touched it, my engine bogged down and almost died, when I let go it revved back up, and I did this repeatedly, confirming that was the culprit. Upon peeling back the rubber grommet, and wiggling the wire it was in fact loose. When I went to tighten it, it dissentigrated, thing broke into a million pieces... LOL I was fucked and in the middle of nowhere, I had to call a buddy of mine over an hour away to bring me new alternator.. Anyway made the story too long, but just check it out.. Other than that, check your grounds, if you have stereo equipment pull the fuse, as that too may be grounding out somewhere...