February 19, 2018, 08:56:46 am » does anyone have diagram for the a/c. Web i don't know the exact year the esc was introduced but the enclosed wiring diagrams show your 83 as having it. Web on this truck the vacuum is pretty basic, im guessing you have a 305 (5.0) or a 350 (5.7), on the front of the engine compartment near the fan shroud somewhere (if it is still intact). Web ported vacuum means little or no vacuum at idle, because the throttle plates at idle shut off the ported vacuum hole. Note<< if picture does not show please email me @ [email protected] and i will send it to you it is detailed.
