Razorthirty Posted July 26, 2015 Share Posted July 26, 2015 (edited) Hey guys, im a bit stumped here. 94 Touring wagon 240k miles. I was at a stop light and just as it turned green i took my foot off the brake and the instant i touched the gas the car died, as though i had turned off the key. No sputtering or cough or nadda, just dead. Had to push it off the road and get towed home. Once home i was able to figure out that the fuse (#16) for the ECU/TCU/ Ignition coils/Alternator was blown. I tried replacing it and it blew as soon as i cranked the motor over. I unplugged the TCU, alternator, and ignition coil. When i turn the key to the on position the check engine light come on *knock sensor, code 22* no biggie, its just an old stored code. When i try to crank the car over it pops the fuse instantly, my next step is to unplug the ECU as well and see what happens, that just take a bit more effort to get to the plugs on it. Was wondering if this sounds familiar or what else i should be checking. Thanks. Edited July 26, 2015 by Razorthirty Quote Link to comment Share on other sites More sharing options...
Cougar Posted July 26, 2015 Share Posted July 26, 2015 If I understand correctly the fuse blows when you go to the START mode and not the RUN mode. It seems strange to me that the fuse controlling those things you mentioned would be effected by the starter circuit. I really doubt the ECU is causing the trouble though it is possible. I don't have a diagram for your vehicle right now so I can't look things over. Check for damaged wires that may have touched the exhaust system and shorted things. To help you find the trouble you can place an ohmmeter probe between the protected side of the fuse socket and ground. Then start disconnecting things and watch for a change in resistance. When the short is removed from the circuit the resistance reading will go higher showing the short to ground is removed. You can also use something like a brake light in place of the fuse. The bulb will limit the current to a safe level and glow brightly while the short is on line. When the short is removed the lamp will dim down depending on the normal resistance of the circuit. Quote Link to comment Share on other sites More sharing options...
Razorthirty Posted July 26, 2015 Author Share Posted July 26, 2015 that is correct, it is fine when i just turn the key to RUN when i turn to START it blows the fuse immediately. i will try looking for bad wiring, that seems likely as i already had to solder the knock sensor wire back together (the code is just still stored because i never reset the ecu, i only unplugged for 10 mins to do the job) Quote Link to comment Share on other sites More sharing options...
Bushwick Posted July 28, 2015 Share Posted July 28, 2015 When you disconnected the ignition coil, did you unplug the actual power harness to it? You might want to try and rule out the starter too. Check and make sure no cables or wires are touching it's terminals. Might want to carefully disconnect the 12v+ power cable; not sure if there's a secondary wire going to the solenoid or not, if so disconnect that too and wrap with electrical tape so it doesn't touch anything. Then try turning the key. If the fuse still blows, it's something else. If it doesn't blow, might be the starter, or a solenoid shorting out internally or something. Though it's possible something is hanging and touching. Quote Link to comment Share on other sites More sharing options...
Razorthirty Posted July 28, 2015 Author Share Posted July 28, 2015 (edited) I unplugged the coil at the 3 wire connector about 3" down the harness from the coil, no change. Ill give the starter a shot as well. Good thing i bought a big box of fuses haha.. I really need to make a 15A breaker with some spades coming off so i dont have to keep wasting fuses. I like the light bulb idea was well. So many projects though, ill do more trouble shooting this weekend and let everyone know what i find. Edited July 28, 2015 by Razorthirty Quote Link to comment Share on other sites More sharing options...
Bushwick Posted July 28, 2015 Share Posted July 28, 2015 It's such a weird scenario that it'd pop while driving, then pop while cranking. Hopefully it's just a worn component on the starter or within the solenoid section and is an easy fix. With the key on, if you can disconnect the solenoid lead and run your own wire directly to the solenoid and get the vehicle to crank + start + run, it should narrow down the field. Hopefully it's not water on the ECM or something. Quote Link to comment Share on other sites More sharing options...
desertsubaru Posted July 28, 2015 Share Posted July 28, 2015 I had a problem with a 96 OB wagon where it kept blowing fusible links. It turned out to be the connections from the bendex to the starter fused together inside the starter. Something to look at maybe. Quote Link to comment Share on other sites More sharing options...
Cougar Posted July 28, 2015 Share Posted July 28, 2015 That's an interesting problem you had there desertsubaru. I haven't heard of that one before. I assume the ignition wire inside the solenoid was coming in contact with the main battery contact inside the solenoid. That would certainly blow the fuse for the ignition circuit. By disconnecting the solenoid wire and isolating it an then try to start the engine to see if the fuse still blows out would tell the story. If the fuse now doesn't blow by doing that simple test then the starter would need to be looked at. I doubt that is problem here but it sure would be easy to prove or disprove it with little effort. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted August 3, 2015 Share Posted August 3, 2015 You ever get this figured out? Was it the starter? Quote Link to comment Share on other sites More sharing options...
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