HELP! MPI relay clicking, power windows and seat dont work

[joyfil2001]

Ok so here is the scoop. It's a 95 TSi with a 95 EPROM ECU. When I shut the car off the MPI relay continues to click (the one with the blue connector) and causes my battery to drain. If I pull the connector the clicking stops and battery does not drain. It also has caused my power windows to not work. I here buzzing at the power window relay when I press the button on either door. I replaced the power window relay which seemed to work for a few days. Now the windows don't work/buzz at all and the power driver seat does not move either. Checked all fuses and they are good. Battery terminals seem to look good.

Should I replace the MPI relay? Where do I start to fix this thing? I have read ALL threads on this topic. Once the car is started the relay doesn't click anymore, but windows and seat still will not work. All interior lights work. Please give me any advice.

 

[twicks69]

Check to make sure that your alternator 100A fuse in the engine bay isn't popped.

 

[steve]

The MPI relay is activated by a ground signal, normally the ECU grounds it to activate the relay and it should only do so when it sees 12v from the ignition switch.

With that in mind it would seem to me that first step would be to measure the voltage on the MPI relay pin and see if it's getting pulled to ground when the key is out of the car. Disconnecting the ECU would help decide if the wiring between the MPI relay and ECU might have a short. Then checking to see if the ignition switch signal might be noisy making the ECU think the car is being turned on. If the ignition switch signal is always 0v with the key out like it should be then the ECU would be suspect. If there is noise I'd make sure there isn't a remote start, turbo timer, or alarm in the car that's malfunctioning and then look at the ignition switch itself.

If you don't have a good multimeter and the correct wiring diagram for your car you need to get them.
If you don't know how to read the diagram or use the meter ask, you're going to need to know how and understand what they are telling you.

 

[joyfil2001]

Thanks Steve. I'm pretty good with the multimeter. There is defiantely no alarm, remote start, or turbo timer on the car. I am the second owner and I bought it stock with 60k miles. So I should unplug the ECU and test the voltage at the relay? Is the relay wired direct to the battery?

Check to make sure that your alternator 100A fuse in the engine bay isn't popped.

Thanks, but I forgot to mention the car starts and runs and drives FINE. The only thing is the power seat and windows do not work.

 

[steve]

The MFI fuse (#4 20A) is between the relay and the battery. The fuse (#9 30A) for the power seats and windows is in the same relay box under the hood.

Both pin 4 and pin 8 of the MFI relay (2G Term) connect to the red/black wires from the fuse. The blue/green wire from pin 6 on the MFI relay is the one that the ECU grounds using pin 38. When it is grounded the contacts close and power flows from pin 4 to pins 2 and 3, powering the ECU and the various parts in the engine bay not on the ignition circuit.

 

[joyfil2001]

Good info. I am going to hopefully test this out this weekend.

 

[Boosted_out]

So I bought the car off Fil the buzzing noise stopped but my windows and power driver seat do not work at all. For awhile when you would push the buttons for the windows you heard buzzing now there is no noise. I checked the window fuse and relays and there fine.
What else could it be?

Thanks Kyle

 

[Boosted_out]

Still trying to figure this out. Any ideas?

Thanks Kyle

 

[Boosted_out]

I have replaced the MPI Relay, the Etacs computer on the back of the fuse panel in the car as well as the window switches and my windows and power seat still dont work. Everything else in the works fine just not the windows or seat.

Any ideas?

 

[dxxparsell]

Mines a 95 gsx and i have the exact same problems and then some, if you found out let me know