Alternator not charging, battery light not coming on

[jhaurimn]

Have an issue with my 87 325 vert. Alternator will not charge fully (reads at around 12.5v when running) and I am not getting the battery light on the cluster with key on engine off.

Things I have tried:
-Swapping cluster bulb with known working bulb
-Swapping clusters with known working late model
-Jumping 12v to alternator blue wire
-Swapping alternator

Any suggestions on where to look next? Appreciate any help. Thank you!

[e30austin]

inspect both halves of the C101 connector for a possible broken blue exciter wire, or corrosion, etc.

[jhaurimn]

Got it sorted, I tried a few things so not sure which ended up being the ultimate solution but this was the winning sequence:

Grounded the blue wire to verify the battery light in the cluster would come on
Cleaned the engine ground (although it looked good and I dont think this was the issue but certainly possible)
Then manually grounded the alternator to the engine ground

After that, working mint. hope this helps someone!

[ADEN]

Got it sorted, I tried a few things so not sure which ended up being the ultimate solution but this was the winning sequence:

Grounded the blue wire to verify the battery light in the cluster would come on
Cleaned the engine ground (although it looked good and I dont think this was the issue but certainly possible)
Then manually grounded the alternator to the engine ground

After that, working mint. hope this helps someone!

When not fixing the root cause:

1- Did you paint your block recently?

2- The alternator bracket area rusted or greasy due to old or new (loil/atf) leaks.

3- Faulty Engine to chassis ground starp due to old or new leaks (oil/atf) to test it engine on (warmed up) switch headlights on to put load on the charging system then wiggle the strap while keeping an eye on voltage it should not change if strap is good.

4- Head to chassis ground is highly recommended (if not present)