Resolved 1G Ignition switch causing SERIOUS short

[dsmdeliveryboy]

Ok so my car lost ALL power and was just making a clicking noise and my battery terminal was getting hot and so I started going through and checking what could be bad. So after I spend a lot of time going through stuff I find out my ignition switch is the problem so I snip all the wires and start going through each wire with a tester and I test the black wire with the white stripe and try adding power from the tester(says on here ignition, fuel)it clicks and loses all power and even blows the fuse in my tester, and as soon as it is removed it clicks again like its clicking something off like its a timer or something. I have no idea what it could be, if anyone knows please help.

 

[wrencher]

Is it the MPI relay that is clicking?
The ign. switch powers the fuel pump portion of that relay.

The blk/wht & the blue/blk are the 'run' wires.
Blk/yel is crank, & blue is accessory.

Sounds like a short in the harness or componet. What size fuse did that tester have in it that it popped?

 

[dsmdeliveryboy]

I'm not sure on the size of the tester fuse, but I do know that if I put power to the line where the fuel pump is there is a clicking sound that sounds like its coming from behind the radio. So what all does the black and white wire go to specifically? Is there a way to bypass or check this? I'm not popping ANY fuses in any of the fuse boxes which is what I don't get.. And I pulled ALL the fuses and check all of that for shorts and everything was fine. I'm so stumped, this is so stressful.. I also eliminated my AC fusebox last night to see if that was causing a problem and nothing..

 

[wrencher]

The MPI relay is back there behind the radio.
The list is big what this wire off the igntion switch powers. Really big....
Coil,MPI relay, fuel pump, alternator relay, seatbelt control unit, fuses 11,12,18 & 19 in the interior fuse box, etc....
Look @ these....

 

[dsmdeliveryboy]

I think it is the MPI relay, I haven't had a chance to work on it with work but I will post results. Thank you for the diagram it is very helpful.

 

[dsmdeliveryboy]

I pulled the relay but haven't had time to test anything as again work has been hectic, I just don't understand how a relay could cause something so catastrophic like this.. I'm really hoping this works, but at the same time I'm feeling there is more to it as much as I don't want to.

 

[wrencher]

Is your fuel pump rewired?
That might be something to look at if it is.

I would start by disconnecting everything from the circuit.
Remove the coil connector, MPI relay's connector, alternator relay, fuses 11,12,18, & 19 seat belt control module & the ECU. Then start re-testing from there.

Kind of hard tested with limited tools @ home so you need to see if it's a componet failure in the circuit or a wiring harness issue.
That wire off the ignition switch will pull in the excess of 10 amps easy, so keep that in mind.
That power feed from the switch is a high amp one. (fuel pump, cooling fans etc)

It is important to know what fuse your tester popped it might have been severely undersized to handle that load.

So at last it ran it was a no crank with the MPI relay clicking with the key on?

 

[dsmdeliveryboy]

Yes the relay was clicking with the key on

No my fuel pump is all stock I've checked all the wiring etc to that as well it was fine.

 

[shavers55]

that clicking is the relay..either the relay is bad or its clicking and not producing an output. Test that relay first. if good then test associated parts before that relay. remember between the good and the bad lies the ugly. use your schematic.

 

[dsmdeliveryboy]

Changed the relay and everything is fixed