Tachometer, Speedo & Fuel gauge inop

[BlakeJ]

My recently "finished" (never really done, is it?) 360R SV runs great the couple of times I've fired it up and driven around the block. Oddly, water temp & oil pressure gauges function fine.

The tach only rises to about 1k RPM (it does move, but that's it). The Speedo doesn't move, though I have not yet tried a new sensor or the extra grounding wire.

 

Anyone else have this experience or any suggestions?

[xcarguy]

Some starting points:

 

 

• First and foremost - grounds?
  
• Tach - does the tach have a 'set switch' (for lack of a better term) on the back of the housing, i.e., 4,6,8 cyl settings?
  
• Fuel gauge - correct ohms range for the gauge (for example, mine is 0-90 ohms)?
  
• Speedo - assuming electric. VSS properly wired?
  

[Sean]

This is a known Caterham-specific issue, and has been brought up on Blatchat before; when new, my car had the same issue. While it could be something else, this would be the first thing to check, and only takes a fraction of an hour to do:

 

Up behind the knee trim panel on the right-hand side (passenger side in LHD car) is a threaded stud with a few grounds attached. From the factory, this stud can frequently have excess paint/powder coat reducing its effectiveness as a grounding point. To check/correct if this is the issue:

 

• remove knee trim panel
  
• locate stud
  
• loosen or remove nut on stud
  
• pull back or remove wire end terminals from stud
  
• remove excess paint/powder coat with knife, solvent, sandpaper, Scotch Brite, etc.
  
• re-install wires and nut
  
• verify gauge functionality has/has not been restored
  

Replace knee trim panel, if desired.

[BlakeJ]

Thanks for the suggestions. Will check grounds.

Also noticed some loose wires from the factory near right rear of fuel tank, so perhaps fuel sender was not connected.