Both of my gauges don't work the mph goes up and down like crazy...can anybody please help me with this problem??

 

The tach is electrical. Check the "METER" fuse in the fuse panel.

The speedometer is totally mechanical. If it's jumping, make sure the cable is securely attached to the back of the gauge. It can fall off sometimes. If it continues to jump, replace the cable.

 

Thank you 4 your help Aaron Cake.

 

Aaron to the rescue!

 

or the cable might have disconected from the tranny at the speedo connecter thingy (im totally blank right now)
easy fix if so, and if it hasnt gotten destroyed.

peace

 

+1

 

Lolz

 

The tach also gets its signal from the trailing coil, so check the connections for that as well.

 

my friend had this problem. i connected a timing light to the trailing wires and no spark or tach. we replaced the trailing coils and we got spark on both trailing coils and tach worked. also got alittle more power. worth a try, connect a timing light and see.

 

will try lets see what happen, thanks.

 

we tried replacing the trailling coils with a good working one and the tach worked for about 4 secs, as it revs up to 3k then the tach cuts out completly, does this every time we start the car, does anyone know what could be the problem?

 

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/no-tach-wont-charge-748446/
check your voltages and check engine light. had similar prob.

 

alternator was da real problem n da trailing coil..now everthing works fine..thanks all for helping

 

damn my tach is not workin again...

 

Im having a similar problem, Tach works intermittantly, as in Ill start it up and it will work fine, shut it off to fill up, and it will cut out when I start it up, and when its not working I get a BEEP BEEP BEEP BEEP BEEP BEEP BEEP BEEP that never ends