ECU electrical problem, possibly

[Eagle 5]

Recently I replaced the tb in my 92 talon. Car ran fine and everything before replacing it aside form some small idle issues when warming up. had a tb bored out/ cleaned and what not. While the tb was off the car I had the key in it a few times to check some things and the car was fine. Then one day, it was just dead. Battery had not voltage. Got the tb back on and setup and jumped the car. Started fine, drove fine etc. Battery drained again. I finally traced it to the middle wire on the small fuse box that attaches to the battery. I believe its the mpi/ starter relay fuse? (dont have the black box anymore, had a distribution block but wires were setup in same order) Got to the large relay box inside and if we disconnected it, battery would not have any amp draw while the car was off aside from the normal few mA. I went to a junkyard and got another large relay (the gold box under the dash) put it in and jumped car again. Idles fine, starts up fine. Then I gave it gas and the windshield wipers came on and occasionally the tach would flicker and jump all over. Only while giving it gas though. At ilde it was fine but pushing the gas in made the wipers come on. So I switched relays back, started ca rup again and it did the same thing again a few times. Then, just went away. Reved engine up, wipers didn't come on, and tach was normal. The relay box was the same p/n and what not so I know the box was correct but is it possible my ECU is screwed up and something in it is causing the battery to drain and not something in the relay box? With the box connected the battery would draw ~1.8 amps when the car was off.

I'm basically trying to figure out what is wrong with the car, and I hate electrical problems. Also, the caps were already replaced in the ecu. They had leaked a little but the place who replaced them fixed it, and said they "rebuilt" one of the traces that had been damaged. Car was driven for over 16,000 miles with no problems. Been running fine for a few years now.

 

[steve]

I don't see anything here that is directly ECU related.

You did something serious to the wiring of the car if your wipers come on from the pushing the gas pedal.

 

[Eagle 5]

That's the part I don't understand. It just started happening one day and I did nothing to the wiring. Everything had worked fine before. I put the new TB on but the battery being drained just happened one day during the time when the car was sitting. One day I went out, car had plenty of battery voltage, next time I went out, nothing. The drain we found coming from the one circuit, which could make sense why the tach was finicky since its on the mpi/ starter relay. But, not sure what would draing the battery from it. Would a bad ground cause that or maybe some wire decided to start shorting to something?

 

[Maglin]

You need to start disconnecting stuff on that circuit and see what is causing the drain. Start off by ohming the power to ground. If you have anything under 60 ohms their is definitely a short somewhere. Being as it isn't blowing the fuse it is most likely a faulty component somewhere. This stuff isn't to hard to find but it's time consuming. If all this power is also feed from the relay take it out and see if the draw is still their.

It could be as simple as the relay ground shorted to ground causing that circuit to stay on. Pull the relay with the car off and see if it clicks. It shouldn't with the key out. If this seems like to much of a task for you take it to a mechanic and it will get taken care of. Might cost you $200 though.