I was recently given a '83 Volvo DL wagon. My friend claims that he put a new wire harness on it but it was missing the pigtail that goes on the ECU located on the front passenger's side wheelwell. I now have the pigtail but need a hand wiring it up. Any ideas where I can find some diagrams on-line that would be model/year specific? I have a Hynes manuel, but this is not giving me what I need. Thanks!

I've got an old Haynes 240 Series manual that has great wiring diagrams in the back specifically for 1983's. The ISBN number for the manual is 0 85696 964 8. The pigtail just above the 25 pin connector at the ECU connects a red wire from ECU pin 16 to the AC switch. It increases idle speed when the AC is on. Pins 1-13 are on one side and 14-25 on the other with 1 at the end where the cable enters the connector. The rest of the pin out is as follows: 1=coil, 2=temp sensor, 3=throttle switch closed, 4= starter engaged signal, 5=O2 shield wire, 6-8=air mass meter, 9=system relay, 10=idle air control motor (close), 11=ground, 12=throttle switch full open, 13=fuel injectors, 14=air mass meter CO2, 15=constant idle speed (ground to test), 16=AC switch, 17=fuel pump relay, 18=fuel pump relay, 19=no wire or ground, 20=O2 sensor, 21=system relay 12 volts, 22=O2 test, 23=idle air control motor (open), 24=no wire, 25=ground (throttle switch). Post back if you need more. jp

Is the pigtail a jumper plug, fit between ECU pins 11 and 19? My 83 manual shows that unused, where the 84 manual has it. Both 83 and 84 DL models use the same fuel injection.

Sorry, don't know of any online year-specific diagrams.
--
Art Benstein near Baltimore