98 frontier, 120k miles, AT: speedometer and tachometer erratic

[3nissans]

Hi fellas:This has been going on for quite some time. Speedo sometimes climbs up to 30 as soon as the truck accelerates and seems to get stuck around there. Today, on the onramp to the I-5 I noticed it jump from about 40 to 80 in about a second. It seems to work fine after driving a while. The tach sometimes seems to be stuck on 3k like this morning. This is at idle and I'm positive the engine wasn't turning that fast. Different times, different tach (high) readings. No rhyme or reason. Again, works fine after a while of driving. Say 30 minutes. Maybe it's because it's winter or something. I don't know. Sometimes, when I hit a rough spot on the road, speedo and tach acts up or corrects themselves if they were already acting up. BTW, the truck has been in a minor fender bender about a few months ago. Front bumper and right fender replaced. Don't know if anything got jarred or something. Ground problem maybe? Thanks in advance for any reply and or tip.Denny

[NISTECH]

Sounds like you may have a unified meter problem. the unified meter is the circuit board in the instrument cluster assembly.

[3nissans]

Nistech:Thanks for the reply. Whoa! That sounds complicated. How involved is this as a DIY job? Doable? $$$? I got a Haynes manual. Would that be of significant help? BTW, I watched the temp gauge today, too. Just to check. Sure enough, I think it went up to temp in no time. About 1-1/2 mile doing 30 mph ave. 40 deg F outside temp. Roughly about 4 minutes with the traffic lights and all. Gas gauge? That one seems to be working fine. So, does this additional info solidifies the circuit board problem? Thanks again.Denny

[NISTECH]

Yea the gauges get al goofy when it screws up. Its a pretty straight forward job but recommend not going used on the part. Go to a dealer and order it with your current milage programmed into it. Should be able to get it over night. It comes out of a place in NY. If the dealer makes the call before noon PT they can usually get it to you by the next day.

[3nissans]

Thanks a bunch. I'll make the trip to the dealer then. Any idea of how much this thing cost?Denny

[3nissans]

One more question Nistech: Is the unified meter the whole instrument panel circuit board or just a part that plugs in? My Haynes manual doesn't give specifics, but the wiring diagram shows (I think) that the unified meter control unit is within the combination meter/printed circuit board. I'm not an electronics/electrical guy so wiring diagrams are foreign to me. Thanks again.Denny
Modified by 3nissans at 7:13 PM 2/21/2008

[NISTECH]

Yes you have to remove and take apart the instrument cluster to replace it.