It is located under the passenger side cowl.
Disconnect battery, of course. I removed mine to give me more working area. The ecu is between the battery and firewall.
1. Remove both windshield wipers (3 nuts 13mm I think)
2. Remove cowl (2 star screws and 4 plastic pins)
3. Remove cowl "drain pan" on passenger's side (4 nuts, deep well 10mm)
4. Remove all four plugs from ECU (small red clip slides up, unlocking plug then gently pry/wiggle loose)
5. Remove ecu (3 small screws 8mm)
That's it. Easy 15 minute job.
You bring it to a mechanic..
on most Chevy trucks the ecu is located behind the glovebox
If, by ECU you mean "Engine Control Unit", I don't believe a 1968 dodge pickup had one.
Were is the ecm located on a 2001 dakota
It is located behind the radio.
The ECU is located under the floor plate on the passenger side on a 2004 Mercedes c230. The floor plate is attached with three nuts.
ECU fuse
Right behind the headlight on the passenger side.
It is located on the driver side fender right behind the battery.
It is located on the driver side front fender behind the battery.
Passenger side of the firewall.Passenger side of the firewall.
The engine computer is at the base of the windshield under the hood, under the wiper cowl.