Today I was helping a friend change his wire harness on his 96 hatch to the ob2 ex harness from a 96-98 ex. He has the following in mods, obd2 ls motor with a obd1 gsr trans. He also is running a obd1 ecu with a jumper harness to connect it with the obd2 harness. We put it in and for some reason it just keep loosing power, the lights start to dim and then its starts to run real low idle and shuts off. Check the battery and alternator, neither one seem to be the problem. When we jump the car it stays on for about 5 minutes then starts to loose the power. Has anyone had a problem like this before? Does anyone know where I can get a wiring diagram/schematics? Any help is appreciated, thanks.

 

is the speedo working?

 

Nope, not sure why not. Its hooked up to the sensor on the trans, unless its broken. Would that draw power though?

 

you possitive its not the battery or alternator... if it runs good when jumped i dont see how they arent the problem/????

 

We took the battery out and had it tested and they said its good, no bad cells or anything. He said he took the alternator out and had it tested after I left and it also checked out good. I figured maybe we connected something wrong that could be draining the power?

 

I think something in the wiring might be at fault, he had this harness in with a jumper connected to a obd1 ls ecu. Now that we are doing the same setup on his car it has this problem.

 

check the fuses under the dash if the speedo is not working then the alt is not charging. truust me happen to me before and i had a blown fuse

 

Will check it out then, thanks

 

Haven't had a chance to look at it but will do today.

 

Is your fuel pump !!! onces it warms up it loose psi. trust me, install a fuel press gauge at start and as the car warms up, you'll notice pressure will drop to a point you'll loose power and car will shut-off.

 

Make sure you hook up the ground wires that are to the Thermostat housing,The tranny ground to the frame and the ground to the valve cover.

 

Need you to clarify...

You said, "it just keep loosing power, the lights start to dim and then its starts to run real low idle and shuts off" can the car be restarted or does it need a boost?

What I need to know is, once the engine stalls, ["shuts off"] is the batt. dead so the car needs a boost to restart?

If so the problem is the alt. is not charging, test the black/yellow lead going to the alt. it must be 12V+ as long as ign. switch is in the run or start position.

Use a multimeter and test the voltage at the batt. and at the alt. lead in engine bay fuse box, [engine running]. 94

 

Yes we ended up using the meter and it read 11.5 volts so the alternator isn't charging. He hasn't had the time to go get another alternator so I will update once he does. For his sake, I hope he fixes it(its his daily driver). His other car is a duramax dually diesel pick up(eats fuel like no tomorrow).

 

UPDATE: He bought the alternator a little over a week ago. We have it at my job now and working on it, installed the alternator and still doesn't hold power. Seems like we will have to go over all the wires in the harness and double check all his fuses over again. If anyone has had this problem then let me know, we are kind of stuck. Anyway I will update once we go over all of it and see what happens.