Joe: It should be 5.0 VDC. Most sensor's for the EEC-IV use 5 VDC as a "reference" voltage. You may have some resistance build up from age/corrosion in the plugs. Check the VREF at the MAF or some other sensor to see if they are all low? . . > > 2. With the ECT disconnected, the car side of the connector shows only 4.36 > volts. Shouldn't I be seeing closer to 12V? > > Joseph van Oss