'Charge' light wont come on after AT>MT swap

[impostor]

After removing the TCU, I noticed the charge and brake warning lights dont come on with the key in the ON position like they used to (engine off). Plugged the TCU back in, the lights come on in the ON position and go out after starting the engine, like they're supposed to. Any thoughts on how to make them work properly?

Thanks,
Jim

[Legacy777]

Can you provide more details as to what you did with the wiring, and what was spliced where.

Which alternator are you using?

My hunch is that the turn on lead going to the alternator is some how tied into the TCU wiring, and with the TCU removed it doesn't get the "ok" signal to activate.

[impostor]

Well what I did was grafted the EJ22t bulkhead wiring harness to the Impreza instrument panel wiring harness. Everything is pretty much straightforward, having both cars' wiring diagrams side-by-side and matching what needed wired together. I didnt connect the AT related warning lights, and I didnt need to worry about the gear position indicator lights as the impreza cluster doesnt have them.

On the Impreza instrument panel, I spliced the black/red wire of connector i6 to the black/white wire of connector f44 of the Legacy bulkhead harness. Seems simple enough. But then looking through the diagram of the Legacy wiring, there is another black/white wire, one end starting inside the combination meter, branching off of the ATF Temp light, through a diode, then to connector B36, terminating at the alternator. I just cant figure out how to make it work without this other wire connected. I guess I can live with keeping the TCU plugged in, I need to keep the functionality of the warning lights (the alternator died on me the other day during rush hour traffic on the interstate)

Im using the 3-wire alternator from the Legacy SS.

Jim

[Legacy777]

Hmm....az2nr is having similar issues, but his won't charge.

[impostor]

Well I have my issue resolved. It turns out that the TCU does play a role in the charging system. Plugged it in and the charge/brake warning lights function normally.

Jim