When my engine is at idle the tach shows nothing. But as soon as I rev it up at a stand still or when taking off from a stop sign it shows RPM's. Even when shifting through all the gears it shows RPM's. Anybody have any ideas what is wrong?

 

could it just be getting stuck down or something? does show RPMs at idle after you rev it? or after you turn it on does it not show anything? hmmmmmmmmmmm thats not really a good answer. somebody who acually knows something will come along.............

 

My guess would be a failing connection with a lot of built up capacitance. Oxides built up on a contact somewhere could cause this. I'd check connections under the hood first since they are subjected to a pretty harsh environment. Some contact cleaner spray from radio shack wouldn't bea bad idea along with re-coating your contacts, where applicable, with grease.

It could be the tach itself inside the cab that is failing as well. Check connections on your instrument cluster, too.

My .02
Dr. Z

 

Have you installed aftermarket guage faces lately?

When I installed mine, I accidentally turned my needle counter-clockwise. It resulted in no reading until I hit ~2300 rpm. I had to pull the needle off the post and reset it.

 

No, I haven't added any new gauges. It's bone stock. When driving it at any speed it shows rpm's. But between shifts it drops off to zero. Then back up again when clutch is engaged. then back to zero again when at a stop light. :cry:

 

acualy, my friend's dad explorer does this now that i think about it. pllllllleeeeaaaaasseeeeeeee don't tell me that we are going down that road now!! jk i still don't know what to tell you though