I found several threads on each of these problems, but nothing on both happening simultaneously.

I have a '95 Accord 4-cyl, wagon. manual, about 175K miles. Pretty much 100% original. My tach & speedo are both jumping in quantum moves, and I think they began this at the same time. At least I noticed both issues at exactly the same time. General direction of the jumping (up or down) is always correct, i.e. they jump up during acceleration & jump down during deceleration.

Tach generally hangs out at 2K or 4K, tracks smoothly above 4K. Never drops below 1.5-2K. Speedo does the opposite: Tracks well from 0-20mph, then jumps to 35-40 and sticks there. never goes above 40mph.

Hopefull the fact that they both went bad at the same time will help narrow down the problem. And I am an electrician/electrical engineer, so feel free to get into the horrid details if you can offer help.

Thanks in advance!

 

The signal for the tach and the speedometer come from different sources, so the only common part between them is the cluster or the wiring.

They both share a ground (along with other items on the cluster). It G402 and G404 that you may want to clean and tighten. G402 is under the center console and access isn't too bad. G404 is under the passenger side of the dash and is not easy to access. It might be worth a shot to sand and tighten those grounds.

The problem is more likely with the instrument cluster. You can remove the cluster, disassemble, then inspect the solder joints on the main cluster board. If you are good with a soldering iron, I would remove the old solder, then redo all of the joints that you can on the board. The other alternative is to buy a cluster from a junkyard and swap the speedometers, so you car will be at the same mileage.

All this information is in a pdf of a 94 shop manual that you can download from the spooner link I posted in the Online Manuals thread in the main DIY section.

 

Thanks for good info. (BTW, I'm a Pittsburgh boy myself!)

You've given me a good troubleshooting path. I've had some suspicious ground-related issues cropping up recently: radio hum & buzz, antenna catching in mid-ascent, etc. So the shared ground is a good suspect. If that doesn't do the trick I guess I'll be spelunking into the dashboard's innards.

I'll post results here. You might want to give me a few days.

 

That 94 shop manual will help immensely. Post back your results or questions whenever you get a chance.

Where part of Pittsburgh are you from? I grew up in Sharon/Hermitage, PA, so its over an hour drive from the north to downtown.

 

I'm from South Park, the other side of the 'burgh. But I have a lot of ties in your neighborhood. My father was born and grew up in New Castle, I have several dozen relatives in the Butler/Cranberry Twp. area, and my uncle's family has a fishing cabin over in Warren. My sister worked in Sharon for several years, her first "real" job after college.

I grew up in South Park and went to Penn State, but moved a lot for business and ended up here in San Diego, a long way away. Just talking about those places makes me homesick!

Did you grow up in the Sharon area?

 

I grew up in Hermitage, which is right next to Sharon. I am a Penn State alumni as well.

 

Hey hey, go Lions!