Spastic speedo needle, temp gague - mileage meter pegged.....

[Turf1600]

I', assuming this is a loose ground or something - but where?

[atomic]

it could be the brass grounding nuts on the back side of the cluster or could even be the si board within the cluster.

[Turf1600]

it could be the brass grounding nuts on the back side of the cluster or could even be the si board within the cluster.

Come to think oif it - the si board did just light up.

[AlpineIS]

If most of your gauges are going nuts, check the condition of your SI batteries.

[dark89e30]

I've been having a similar issue... I just put in a different cluster (VDO) due to broken stuff on the old one (Motometer). My speedo has only been working occasionaly and as soon as it starts giving me a reading, my odo starts working along with my mpg gauge. Anyone know where these three functions tie together in the circuit board? Also does anyone know for sure how the mpg gauge gets its readings? My guess is that is uses a combination of mph signal along with injection pulsewidth. If it does use pulsewidth than the gauge readings would be inaccurate with aftermarket injectors. It would say that mpg is better with bigger injectors. The damn thing reads around 40mpg and I know thats not right for these things...