I got a 91 Si, OBD2 zc (D16y7), OBD0->1 jumper harness, P06, TD-41u dist. (d15b7 0bd1)

Like i said there is 12v at the thermostat ground, so I guess the starter wont ground to the block if its positevly charged, I bench tested the starter and its in woring order. The grounds from the thermostat go back to the main relay and to the ecu so when i unplug all these plugs it goes away. Ive tried 2 ecus, 3 main relays among other things. Anyone have any insight?

 

What about the ground from the valve cover to the frame?

Also ground from the battery to the clutch switch.

 

okay what??? you have 12v at the ground terminal???

 

they are fine, its just when you un hook the thermo ground and test with a test light there is 12v.

 

you need to find out why you have 12v power at the thermostat ground - shouldn't have power - must have a short somewhere or a 12v power wire connected to the ground wires

 

not trying to insult but is your battery hooked up in the correct manner?

 

Here is a stupid one.

When you try to start the car, what happens?

Look at the temp gauge. If the temp gauge automatically pins to hot you have an open ground. Most of the time it is the starter, but since you checked that then you have a ground open.

What about the ground under the dash right next to the column?

 

yeah batt is fine
I know I have to figure that out lol, like i said, traced back, even replaced chassis harness, its something to do with the ground running from the main relay to the thermo ground.

 

should be 4 wires at the thermostat ground - 1 black which comes from the cooling fan switch - 1 black which turns into 3 wires in the harness, 1 to main relay and 2 to ECU at pins A2 and A4 on the OBD0 harness - 1 brown/black which goes to ECU pin A16 on the OBD0 harness and the shields on the distributor wiring - 1 black/red which goes to ECU pin A18 on the OBD0 harness and to the shields on the distributor wiring

 

yeah, when i test the fanswitch/relay ring terminal there is 12v (bright light) and the other ring has a faint light to it. this is with a known good chassis harness, and engine harness.checked all the wires. seems to be originating fro the main relay. but ive tried 3 different ones and, like i said the harness is different also.

 

i would verify that the jumper harness wires go to the right place:

OBD0 A2 > OBD1 A23
OBD0 A4 > OBD1 A24
OBD0 A16 > OBD1 B2
OBD0 A18 > OBD1 A26

 

ive ran the car on the jumper harness before. thats why i cant figure this crap out....everything is fine. is there 12v+ on the dist harness anywhere. only thing i can think of is that the shields on the dist harness from where i swapped on the obd1 plug are touching a 12v on the dist part of the engine harness.

 

12v at the distributor is the black/yellow in the 2-wire connector

 

ok ill check everything and letyou guys know. im about to tear my hair out.lol

 

check your 4-wire O2 sensor wiring - the O2 sensor shield also connects to the distributor wiring shields

 

i just wired straight to the jumper with a 4 wire female. ill check them too. thanks

 

ok checked all shielded wires, even cut them off. unplugged o2 curcuit. light still on. one thing i noticed if you ground the - of any sensor to chassis the light goes out....almost. its still faintly lit..faint, i mean faint, but still there.

 

ttt