Lost power to dg(darkgreen)/Or(orange) wire feeing coil & injectors

[Ondonti]

1992 SBEC P body 3.0L
I was driving up to the dyno today and the ground wire on my starter popped off (its a female quick connect not bolted down, stupid design).

It might have shorted on the postive or something else may have happened.

I first noticed the car losing all engine power so i pulled over. I then turned off the engine as I rolled down the freeway exit to try to restart the engine to see what kind of problem it was. No start. Pulled over and found the ground wire for the starter off and put it back on (so it wont come off now) but now the DG/O wire that feeds my injectors and coil wont get power from the shutdown relay. I swapped all relays with ones from my daily driver, swapped computers. No luck.

My guess is "something else" is the problem and the relay not triggering is a symptom of the real problem.

I went through my factory wiring book but the best I can do is trace the DG/O wires. It seems to be a problem of that wire not getting voltage from the relay. That is why I thought swapping relays or computers would help.

All the other wiring seems to work fine (that I know of. No codes except 31 which is the purge solenoid that doesnt exist).

[NAJ]

Power to the ASD and Fuel Pump relay is on circuit A21 14DB which comes from the ignition switch. The ignition switch is powered from underhood fuseable links.

Sundance Duster V6-181 2972cc 3.0L SOHC VIN 3 FI
Vehicle Level Powertrain Management Computers and Control Systems Main Relay (Computer/Fuel System) Testing and Inspection


Testing and Inspection
Note: The relay terminal numbers can be found on the bottom of the relay:
Terminal Identification
Terminal number 30 is connected to battery voltage and can be switched or B + (hot) at all times. ^ Terminal number 87A is connected (a circuit is formed) to terminal 30 in the de-energized (normally OFF) position.
Terminal number 87 is connected (a circuit is formed) to terminal 30 in the energized (ON) position. Terminal number 87 then supplies battery voltage to the component being operated.
Terminal number 86 is connected to a switched (+) power source.
Terminal number 85 is grounded by the PCM.

[Ondonti]

so turn the ignition switch on and test the auto shutdown relay in that manner.
The factory wiring diagram is easy to follow but it doesn't tell you where electricity is supposed to go and not go etc.

[NAJ]

If I am reading the wiring correctly ;
Circuit A14 16 RD/WT is a power feed from a fuseable link to fuse # 13 (10 amp) to the IOD fuse connector(natural color behind battery) to the ASD Relay connector.

Circuit A21 14 DB is switched ignition voltage from the ignition switch, also runs to the diagnostic connector.

So terminal #'s 30 and 86 should have power in the start position.(RD/WT and DB wires)
Terminal 87 is the output to the + coil and injectors.(DG/OR wire)

[Ondonti]

I just plugged bansheenuts OTC scanner into my dead duster and it wont turn on. Plugged it into my Spirit and it works fine.

So I guess the problem is not that wire, but the fact that the ECU is probably unpowered?

[NAJ]

2 things to check,
1) The battery is fully charged
2) There is power at the DB wire in diag connector with the key on.
Here is some other info that may help.

[Ondonti]

It was just the ground wire for the cigarette plugin was off.

[Ondonti]

I tested on both cars. I just realized that with key on, there is no voltage except initially. When you try starting the car voltage jumps up to 12. It was the same on my functional Spirit and the broken duster. The Dusters battery is weak from troubleshooting on the side of the road so I put it on the charger here at home. I was able to get it to send some sparks across a plug just now but the battery is now too weak to hit a spark on this old plug I found in the driveway.

The scanner was able to get the injectors to fire during testing.

[NAJ]

You can actuate the ASD with the scanner, the power will be pulsed it will not be constant. Actuate and check power at the + coil and you should hear the fuel pump run.

[Ondonti]

Okay so working in a slight amount of darkness and having a scanner rocks.

I was trying the OTC tests. i was testing the injectors etc. then I tried testing the coil. I found that it was sparking from my coil to the coolant return line somehow..........

I fixed that and the car started.

BAH.

I guess what sucks the most is that my misunderstanding of how that DG/O wire worked (no voltage when on and not running/starting/priming pump) lead me away from fixing the car.

[NAJ]

So the coil case was cracked and arcing to ground. Glad you found the problem and the car is up and running.
Was frustrating while you were diagnosing but experiance is the best teacher.

[Ondonti]

I have a weird coil setup custom mounted and it got pushed towards the coolant return line. I just pushed it back and it works. I will need to improve that I guess.

[NAJ]

Isn't a 92 the "brick style" coil with a sealed connector?

[Sittn86]

IIRC, my '94 V6 Duster has an oil-filled coil. I think only the 4-cyl's got the resin-filled coils.