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Is my ECU fried or what?

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  #1  
Old 10-02-2012, 10:49 AM
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Default Is my ECU fried or what?

All right, here is the big mystery. I am trying to be the good uncle and fix my nephew's 97 accord v6. A few weeks ago his car died. It was his altenator which killed his battery. Installed a rebuilt altenator and new battery. He said the car's battery light came on twice since the install. I told him not to drive it until we can check the altenator. He still drove it and one time he needed a jump to get it started.

The other day he was driving on the highway and the car completely shut down on him. He popped the hood and said the battery was smoking. Towed the car home and he called me. Removed the alt and had it tested. It tested good. The battery looked like it over boiled and was beginning to melt. Needless to say I replaced both the battery and the altenator. Installed and the car cranks but no start. Checked all the fuses and the fuel pump fuse was shot. Replaced 15amp fuse and popped again as soon as you turn key to second position before you try to actually start it but the car still cranks.

After careful research online I decided to change the main relay, fuel pump fuse (again), and restart car. Same outcome. Fuel pump fuse blows... again.

I checked eveywhere for bad grounds and I cannot see anything that looks bad. Checked O2 sensor grounds, etc. Next, I checked codes. I checked three times with my OBD reader and each time it stated "link error."

Ok... I decided to check all fuses and the only fuses that were blown were the ones that are in the car. It was the window wiper fuse, SRS fuse, and the fuel pump fuse. I changed them all and when I went to start the car, same result, those three fuses were blown.

Questions: Since the ODB cannot establish a link is the ECU fried? Can this be the source of the fuses blowing and car not starting?

HELP!!!!!!!
 
  #2  
Old 10-02-2012, 05:30 PM
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I wouldn't say it's the ECU yet.

First and foremost, sounds like there is a short in a wire or electrical connector. A short is an accidental connection of a wire to ground or to another wire. I would be checking the wiring and connectors very carefully in the engine bay near the battery, alternator, and fuse box.
 
  #3  
Old 10-03-2012, 11:09 AM
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Ok, I will check.
What about the fact that the OBD reader is not linking to the ECU at all?
 
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Old 10-03-2012, 11:35 AM
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The short problem may be tied into electrical power circuit the ECU/ECM uses.
 
  #5  
Old 10-05-2012, 11:51 PM
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Originally Posted by redbull-1
The short problem may be tied into electrical power circuit the ECU/ECM uses.

UPDATE: I did not get an ECU.

Today I had a chance to check EVERY wire that came from the Alt. I checked all grounds and the battery ground. They all were fine and secure. I checked the battery 100amp fuse and all fuses in the fuse box under the hood were fine. I replaced all of the blown fuses under the driver's side dash. I reconnected the ECU. I gave the key a turn and the same fuses blew again.

Out of frustration I decided to see what would happen if I put a 30amp fuse in the fuel pump fuse location instead of the 15amp. Turned the key and heard the fuel pump prime and fully turned it and the car fired up no problem. I know, I know, it is not a resolution, so I turned off the car and removed the 30amp fuse. Out of pure curiosity I installed the proper 15amp fuse and tried to start the car. The 15 amp fuse did not blow and the car started right up. I must have started the car 10 times after that and no fuel pump fuse problem. WTF?

Now, the only fuse that keeps blowing is the 30amp windshield wiper fuse as soon as the car gets power when I turn the key. What the hell is going on?
 

Last edited by likethatyall; 10-06-2012 at 12:38 AM.
  #6  
Old 10-06-2012, 12:23 AM
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Are these fuses in the fuse box under the dash or in the fuse box in the engine bay?
 
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Old 10-06-2012, 12:36 AM
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Originally Posted by PAhonda
Are these fuses in the fuse box under the dash or in the fuse box in the engine bay?
Under the dash.
 

Last edited by likethatyall; 10-06-2012 at 12:38 AM.
  #8  
Old 10-06-2012, 01:34 AM
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Is there any aftermarket electrical items installed in this car like stereo, remote starter, alarm system, etc...?

Also, which fuse numbers are blowing with the pic below:

 
  #9  
Old 10-06-2012, 06:37 AM
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Originally Posted by PAhonda
Is there any aftermarket electrical items installed in this car like stereo, remote starter, alarm system, etc...?

Also, which fuse numbers are blowing with the pic below:

When I look at the fuse box and compare it to the diagram above, the diagram is backwards (ie: the aux fuse holder is on the left). I am going from memory, so i believe it would be fuse #4 according to the diagram.

There is an aftermarket stereo but it uses the factory harness.
 
  #10  
Old 10-06-2012, 10:17 AM
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Is the "cover" still around to be sure?

I see the fuses in that row as

#4 - 7.5 amp - Alt, TCU, fan - a few others
#5 - 10 amp rear wipers for a wagon
#6 - 30 amp for wipers, interm relay, washer motor

If it is the wiper fuse, start with disconnecting the wiper motor.
 


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