IF your Fuel gauge .. works.. Ie it goes up when you fill the tank and goes down when you drive.. even tho not giving a full reading when you know there tank is actually full. THEN it's not yer Sender .. the thing inna Photo (although these ARE rebuildable.. if one was of a mind to 
You merely have to tighten the Grounding Nuts on the rear of the Dash Gauge..(Saabs are seriously affected with Ground issues
accessed (with significant difficulty tho) thru the Speaker hole. Persevere it IS possible.. barely.
Usually these need only an 1/8 turn or so.. this Works. as advertised.
You merely have to tighten the Grounding Nuts on the rear of the Dash Gauge..(Saabs are seriously affected with Ground issues
Usually these need only an 1/8 turn or so.. this Works. as advertised.