Battery light on but battery charges

[Reubenh]

Hey guys, I am in the process of swapping a beams into my SW20.

I wired up the alternator as best as I could. Unfortunately the loom was cut but I have connected everything - wire colour to colour.

Another question I have is about where the signal to the tacho goes in to the fuse box. I have a link ecu and of course that and the COPs mean that I no longer have a taho output. I can easily make up a device that will simulate the tacho voltage spikes but I don't actually know where to put the signal..

Any help appreciated.

[GDII]

Does the LINK not have an output for Tach? Which model LINK are you using?

For the alternator, I'd check the wiring first before connecting up a battery. Just because the colours match doesn't mean they go to the same place?

What year and model car are you swapping into? And is the BEAMS from an MR2, Celica, Caldina or RAV4?

[mknz]

Tach was the black wire if you have that

[Reubenh]

My car is a 1990 JDM 3SGE Manual
The engine is from an altezza with a reasonably custom wiring loom and loads of mishmash or custom bits to fit it in the hole.

The alternator is the factory mr2 one going from what I can tell pin to pin to the fuse box arrangement. I don't really know how they work and what voltages I should expect on each wire etc

I am using a G4+ storm. It has push to start and all sorts wired up, it's great fun.
I'll look for a black wire in the fuse box and see if it goes to what's left of my original loom later on.

[GDII]

That make things complicated. Without seeing the car or understanding what has been done for the wiring it's going to be hard to help.

However Pin 5 on Plug EA3 is the tacho on the JDM 1990 3SGE harness.
Charge light is Pin 4
Alt Sensing is Pin 17

GEN2 3SGTE EA3.JPG (50.19 KiB) Viewed 663 times

Power in pin 7 in EB1

GEN2 3SGTE EB1.JPG (39.49 KiB) Viewed 663 times

[Reubenh]

Thanks for that.
The body harness is completely unchanged from factory and the engine loom is mostly custom (and I only know about what I implemented. There is lots on the original, butchered loom that I have not hooked up yet. Much of it doesn't even matter)
I'll get into it later in the week, probably tomorrow

[GDII]

I had the light stay on when I did a turbo swap, was actually due to the wiring at the alternator being messed with by someone... So once I fixed that it was fine.