When I plugged your symptoms into the factory manual system, here is what I got:
1996 - 2002 Chevrolet Express Cutaway and GMC Savana Cutaway Turn Signal Flash Too Fast, Opposite Side Dim - kw flasher connector dim electrical ground hazard lamp left indicator #PIT3356 - (Jan 6, 2005)
1996 - 2002 Chevrolet Express Cutaway and GMC Savana Cutaway Turn Signal Flash Too Fast, Opposite Side Dim
The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.
The turn signals flash too fast and the opposite front turn signal bulb illuminates dimly on 96 thru 02 vehicles using the g van cutaway chassis without the uplevel front end appearance package. The exterior light system was designed to use separate rear Stop and turn signal lights. This condition can occur if the body builder installs a combined stop and turn signal light.
The rapid flash rate concern can be corrected by removing the original flasher and installing flasher p/n 12450057. It will also be necessary to splice the light blue wire circuit 1508 and the light green wire circuit 62 from the flasher, together. It is not necessary to remove either wire from the flasher connector. A jumper wire can be used to connect the two circuits together.
To keep the opposite front turn signal bulb from coming on dimly, the turn signal resistor (R100) should be removed. This resistor is located on the radiator support panel and is illustrated in the 97 G van service manual on page 8A-201-9 of book 2. After cutting both of the wire leads, tape them back to the harness making sure they are insulated from ground and each other. Discard the resistor.
I hope this helps.
Take Care, Greg A.