420A Mopar Performance ECU in a 420a w/1 issue

[blowinsmoke95]

Okay guys.. now b4 I get flamed and told that it ABSOLUTELY WILL NOT WORK, please read this entirely.

I recently just aquired a 97 420a speed Talon, and while I was washing the engine bay eariler, I happened to remember that I have both a 97-99 SOHC neon Mopar performance ecu and a 96 dohc neon mopar performance ecu. (from previous cars)

While my inner child got the best of me I immediately unbolted the stock ecu and installed the 96 mopar performance neon ecu. The car started up right away and idled smoothly. I then notice the battery light staying lit, I popped the hood and checked all connections, all seem to be good. So I took the car for a drive wondering if maybe it was the water on the alternator causing the light. The car runs flawlessly and honestly has made a huge difference mid-high range and the added rpms seem to get shifts perfectly right in the fat part of the power curve. Needless to say a drastic improvement over stock.

However the battery light issue still persists. My question is, has ANYBODY ever done this and had the same/similar issues? I will be testing the output current of the alt to see if maybe it is over or under charging, but im honestly thinking it may have something to do with a neon having a battery temp sensor and a 420a car doesnt. Just looking for a little more info to see if anybody else has ever tried this and what/if any issues they are having.

 

[silvreclips]

All you need to do is check the voltage at the battery to see if you are charging or not. The neon ecu also has the voltage regulator internally like the stock ecu does. So unless the ECU pins do not match up exactly I dont see why it wouldnt be charging. The ECU tells the battery light to come on when the voltage is low so you would need to check that pin as well.

 

[Slo2gen]

You can run the Mopar ECU but there are a few pins that need to be repinned to the correct posistion. As far as battery light coming on, just run an external voltage regulator. I made that switch a long time ago and its seems to be a steadier voltage than the one built in the ecu, I would just recommend a volt gauge to keep an eye on it. If it goes and the alt overcharges you can have some issues with blown bulbs, sensors, and or ECU's...

 

[blowinsmoke95]

Would u happen to remember which pins they were or know of a place that I can get a direct answer?

 

[silvreclips]

Find an ECU pinout of the eclipse ECU and the neon ECU and you will be set. Not many people do this swap

 

[blowinsmoke95]

Find an ECU pinout of the eclipse ECU and the neon ECU and you will be set. Not many people do this swap

Yeah ive tried that, seems as tho everything is giving me the same pinouts.. but I know that is not correct.. and whats even more frustrating is even the Chrysler service manuals are wrong when it comes to wire color/designation.