You may have a vacuum leak or a check valve isn't working in the HVAC system. When there is no vacuum in the system it defaults to defrost. Under load the engine vacuum drops to almost zero. Normally the HVAC system has a vacuum reservoir to maintain operation during this situation, but if there is a leak it cannot hold vacuum.
Where is the computer located in the 1995 ford e250 4.9l engine
There is a brake reservoir under the hood of the engine. It is located typically in the back right section of the engine compartment (near the drivers side).
where is the crank sensor located on a ford e250 1999
5,340 lbs according to uhaul.com
most e250 turn sig. flasher are located on fuse box (under dash) small metal box
The vehicle speed sensor on Ford E250 is located underneath the vehicle on the transmission beneath the intake mainfold.
Overdrive allowed is the normal position
passenger side firewall
on the throttle body
Take off the camshaft.
it's located under the dash by the steering column