Can anyone tell me what this is, and what is does?

[joew94th]

This is on a 1966 Belvedere II. Engine is not original. It's 360. It's mounted under the hood on the driver's side fender well. It's been on the car since I bought it five or more years ago. That looks like a transistor and it's connected to the negative side of the battery. The connector has five terminal posts on it. I'm guessing it's aftermarket since I can't seem to find it in my service manual. Any help is appreciated. I guess I could follow those line to see where they go, but I'd have a lot of unwinding to do.

 

[RJRENTON]

This is on a 1966 Belvedere II. Engine is not original. It's 360. It's mounted under the hood on the driver's side fender well. It's been on the car since I bought it five or more years ago. That looks like a transistor and it's connected to the negative side of the battery. The connector has five terminal posts on it. I'm guessing it's aftermarket since I can't seem to find it in my service manual. Any help is appreciated. I guess I could follow those line to see where they go, but I'd have a lot of unwinding to do.

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It's the control module (ECU or Electronic Control Unit) for a MOPAR style ignition system. The large TO3 transistor switches the coil's primary current on and off for EVERY spark. PROPERLY AND EXPERTLY GROUNDED......which is why it's still in service.....most don't ground the module as well, resulting in problems.........just my opinion of course......
BOB RENTON

 

[RR Fan Dan]

It’s the ECU for the ignition system. It was on later cars, not sure what year they started. Here is a picture of one on my 74.