87 300SDL Tachometer Stopped Working
 

Yesterday I was driving and the tachometer stopped working. Does anybody know how the tach works, and operates. I think I have heard that it work on air pressure or something. Does anybody know how to fix it because i dont think that the actual meter is broken.

OverVoltage Protection Relay
 

Find this sucker,and check the blade type 10 Amp fuse in the top of it.

('Behind the Battery?)

It must be contagious, mine stopped working on the way home tonight. I guess I'll check the fuse tommorrow.




'91 350SD 535,000 destroyed
'87 300SDL 254,000
'94 SL500 45,000

It wasn't the fuse in the overvoltage protection relay. Any other ideas?







'91 350SD 535,000 destroyed
'87 300SDL 254,000
'94 SL500 45,000

Mine quit some time back, it was an IC on the tach board. So hard to get the IC, the shop just replaced the tach board with another working board with the correct ratio.

replaced the fuse and its works again.

On my SD my tach was working intermittently you might try checking the grounds on the back of the inst. cluster.

just an idea...