OK - I have posted a few times about every once in a while hearing an electrical noise - "buzzing" coming from the instrument cluster.

Well here is what I have found out!

When in a certain gear - 3 or 4th I think and the RPM's are constant between 900 and 1100 ( usually about 30 mph) the "Buzz" is coming from the tach.

Doesn't seem to happen in the lower or higher gears, does not happen when the Tach just passes through those rpms, just when its constant.

I have 38K on the truck and it has just been the last few weeks I think.

Any ideas? (Please refrain from saying I'm nuts!!!!!!)

 

I had the same problem and after DC replaced the cluster showed up again, so I went in search of this noise. I found that my go petal was vibrating were the cable attached to my pedel, put a rubber o-ring was gone traded the truck the next couple of days. Search there is an article I wrote about this noise. Don't know if yours is the same but may help.

flgc

 

Looking at a 3500 the other day and while adjusting the electric driver's seat, the tach needle would vibrate

 

Any help would be nice........

 

Was there any fix? My tach is acting up now, drops to 400 when engine rpm doesn't change, hold at 1000 and it will suddenly drop to 600 and snap back up but actual rpm is not changing.