Boosthead

The speedo in my Dad's civic is acting crazy. It will intermittently jump around or drop to 0 mph. Sometimes it will read 100mph when travelling 40 mph. My initial thought was that it was a bad VSS, but I replaced it with a good working VSS from my car and still no prob. There is no CEL. Outside of a bad speedo or cluster, is there anything else I should check?

lohatch

damn i was gonna say check out the sensor but since you already did that i guess that isnt the problem. my buddies 98 does this somtimes too. any help would be appreciate on this topic

Boosthead

I'm sure there has to be a way to test the speedo itself so if anyone has insight, it would be greatly appreciated.

RacerXI

Make sure to check the prongs for corrosion or trash on the VSS.

*edit*..anything that would cause a bad connection..

Boosthead

Thanks. I know the VSS is good, but I will check the plug again and see if it needs to be cleaned up. Do you know if there is a way to test the speedometer itself? The other gauges in the cluster work fine.

PLAN:B

Check the alternator. I know your thinking, "WTF!". Well mine was jumping all over the place so I called my friends @ Access Motors, and they said to check the alternator.

On the top of the alternator there is a 10 or 12mm nut that connects wires to your alternator. It's under a rubber cap. Sometimes it gets loose and you just need to tighten it to get a solid connection. Mine was only hand tight, and after I tightened it, everything was fine.

That might not help you but it worked for me. Goodluck.

KeithsDAteg

Check the speedo cable on the back of the cluster and on the tranny??

Mine did the same thing once and it just had a bad connection.

703_Sleeper

kool i'll definitely try this, had the same problem.

Boosthead

Are you talking about teh electrical connection? There is no "speedo cable". It's all electronic.

EX-T

I had/still have the same problem. Here are the things that I have eliminated as factors...

1) VSS
I've put 3 VSSs in and it still jumped around
2) New Tranny
I put a new tranny in b/c my 3rd gear synchro was gone and possibly thought that the spider gear that the VSS determined speed from was messed up. It wasn't!
3) New Instument Cluster
I got one out of a buddy's car just to see if that was what it was. That wasn't the case either
4) Checked the Alternator/VSS fuse to see if it was blown. It wasn't
5) Checked the ground on the Thermostat housing to see if it was loose and it wasn't.
6) Checked the wire on the Alternator that PLANBmotorsports was talkin' about and it wasn't loose.
7) I also replaced the plug on the harness side that plugs into the VSS on the tranny and that didn't fix it either.

So, I've came to the conclusion that there is a short somewhere between the harness plug at the VSS and the plug in the back of the Cluster. I've got a buddy that runs an automotive shop and he is getting me some troubleshooting print outs and a wiring schematic for the VSS to see if we can weed out some other things.

As for you, I would check all of these things and see which fixes it and if none of them work I'll keep everyone updated as to what conclusion is drawn when I trace the wires.

KeithsDAteg

yes there is a cable that runs from your tranny to the back of your gauge cluster. If you dont believe me take your guage cluster out and check for yourself. Or just look on top of your tranny in the engine bay.

mc

i had the same problem with mine I switched out the cluter and put my speedo in the new cluster. I switched the little thing that clips into the back of the speedo and the problem was fixed

s2000june

what do you mean you (switched the little thing that clips into the back of the speedo ) did you cut the like 3 plugs that go into the cluster and re wire them? with new ones. ive got the same problem as Boosthead
my car does the exact same thing.
i got a 92 vx hatch. i did it with the vx motor a y8 swap and now my gsr swap. it comes on and off. usually its a 100 mph or 0 though. but sometimes it will pop back to 40mph or the right speed outta nowhere. so i know its not the actual sensor. its either something in the back of the cluster . or the acutal plug on the harness that plugs to the tranny maybe i need to cut it rewire it with a new plug. i dunno . Someone figure this out so we can all fix are probs.
Bump for the broke speedo Crew!

mc

first thing i did was take the clear cover off the cluster. Then take the three screws out of the back of the cluster that hold the speedo in. It should just fall out now. Then there is a little circuit board on the back that is held onto the back of the speedo with two or three little plastic clips. Just be carefull not to break anything. I am guessing the problem with mine was in the circuits in the back of the cluster since I am still using my original speedo and it's been working problem free for a few months now.

scratchy

well get ahold of another cluster and see if it does the same thing or not if it still does the same thing and you are positive that the vss works then you have a wiring prob and you don't want to deal with that, prelude type sh have the probs alot to and is always some bullshit with the wiring in the cluster

scratchy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bigcrazydude1 &raquo;</TD></TR><TR><TD CLASS="quote">Check the speedo cable on the back of the cluster and on the tranny??

Mine did the same thing once and it just had a bad connection. </TD></TR></TABLE> these forum is for 5th gen and up

ham

i bet you that the signal wire is getting noise from another wire, causing a minor short.

cut the wire at the vss and run a wire outside of the car to the back of the cluster and see if that temporarily fixes it. Make sure it doesnt contact the old signal wire.

mugenhatch92

mine does it to

JJW

Bump

hndakd

mine has beed doin that **** for a long *** time. i found that the signal wire had a short in it. so i wired it directly to the ecu,but i still get no speedometer reading. does any one have a wiring diagram for the vss? I hooked my wire to the speedometer and i started to throw the code again and the speedo didnt work???? but when i hooked it up to the ecu i got my vtak back and it was fine accept for the speedo. does enyone know if the speedo is ran off the same wire or gets a signal from the ecu&gt;? car is 98 civic 94 gsr and gsr dash if that helps.

ham

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hndakd &raquo;</TD></TR><TR><TD CLASS="quote">mine has beed doin that **** for a long *** time. i found that the signal wire had a short in it. so i wired it directly to the ecu,but i still get no speedometer reading. does any one have a wiring diagram for the vss? I hooked my wire to the speedometer and i started to throw the code again and the speedo didnt work???? but when i hooked it up to the ecu i got my vtak back and it was fine accept for the speedo. does enyone know if the speedo is ran off the same wire or gets a signal from the ecu&gt;? car is 98 civic 94 gsr and gsr dash if that helps.</TD></TR></TABLE>

the wire does a T. theyre all connected.

hndakd

so if i split the wire comin from the sensor and run it to the ecu and the speedo it should all work??? cuz i tried that and started throwin the code again.

hndakd

ok bump this so ican get some more help maybe. i ran a wire from the vss to the ecu, i get my vtak back. I ran the same wire to the speedometer and it didnt work???? i changed clusters 3 times and it still didnt work. any help is greatlyappreciated i really would like to know how fast im going.

Evilthorne

I have the same problem on my 92 si. In my case it jumps all the way to the pin under 0 then slowly moves towards 100 then when I slow down it goes up to the pin again. kinda annoying.

Evilthorne

I pulled the plug off the VSS, all coroded inside cleaned it up plugged it back in again and I got a CEL. This car is killing me everytime I fix something something new breaks.