Hey guys, I have a 99 hx coupe with a obd1 b18c1 in it.

Normally my speedo will work perfectly fine until I start to give it some throttle. (80% or more) when I do the speedometer needle will start to jump around going up to 140mph back down up etc. I did a few tests on the connector itself, It read like this.

Power = battery power 12v good
Signal = 5v and would pulse when I spun a wheel by hand.

Now on the ground wire I did a continuity test in ohms it read .51 Is that my problem a bad ground?

I checked all the fuses none of them popped or anything.
Thanks in advance

 

sounds like a bad ground... check ground from chassis to trans?

 

Yeah that ground is fine. But I was thinking the same thing... Appreciate the help man.

 

Anyone?

 

Please? I've searched and never found a definitive answer.

 

check back of cluster all the screws are tightened?

 

^^Thanks for the input. I'll have to give it a shot. Not sure if it's a ground of not because I checked a few today and they were all fine. Maybe I'll have to check the one going into the vss itself. Could also be a corroded plug I'm going to stop by a junkyard tomorrow a splice into one.

 

i had this same issue and i took my speed censor out and cleaned it. no more problem

 

What part did you clean? The plug? I've done that, it works for a few miles, which leads me to believe it's the plug...

Anyone else? I appreciate the input guys.

 

It does sounds like a Ground /Ground loop problem... Have you wired up a stereo or amp lately?

 

http://techauto.awardspace.com/vss.html

 

Thanks man! I'll give this a shot and report back.