The 1990 Ford E-250 van doesn't have a transmission dipstick for checking the automatic transmission fluid level. Automatic transmission fluid level is checked differently, usually by removing a specific plug on the side of the transmission case while the engine is running (and possibly warmed up to operating temperature). This requires a specific procedure that is in your owner's manual or a Ford repair manual to do correctly. Checking it incorrectly can be dangerous.
Do not attempt to check the fluid level yourself unless you are experienced with this procedure. Incorrectly checking the level can lead to damage to your transmission. It's best to take your van to a qualified mechanic for transmission fluid checks and service.
