I just picked up a '99 sl1, when driving at an idle in 5th (2000rpm) the speedo and tach will go dead then reset themselves...the e-brake light also comes on. They will drop down to zero then reset and go back to normal. the fuel and temp gauges don't change though. the car doesn't run any different and i cant seem to figure out what sets it off. Any help would be appreciated.

 

Check the output AMPS and VOLTAGE of the alternator under LOAD.

 

Also check the positive battery cable for any corrosion, replace if you find any inside of the cable itself.

 

k thanks i will try that out and let ya know

 

so i got it tested and apparently there is a diode fault. but now i gotta rip half the engine apart just to get at the thing?!?! haha is it just a matter of taking the powersteering pump off or is there a better way???

 

through the wheel well is also an option (removing plastic liner of course)

 

yeah well it will probably have to wait a bit, too cold to work in the unheated shop right now. also...much to my surprise the negative battery cable was actually ever so slightly loose, since tightening the gauge death hasn't happened. will wait and see if that was the easiest fix ever.