Been chasing this issue on the weekend.
Symptom:
after a while of driving, alternator cuts out. Might cut back in, random.
Measured everything. 13.3 - Alt bad
Had the starter out, changed the contacts.
Nope, "better" and smoother but still cuts out
Thought maybe heat related?
Changed the diodes board and the regulator part.
Nope.
Second time I had it out I saw some red stuff.
Remembered this morning that the truck has the nice Toyota red in it, because of the new engine.

Drove. Looked. Yup.

The coolant hose coming of the timing chain cover assembly is leaking right on the alternator. New engine, new hose, wrong clamp.

A heads up if you have this issue!

(and yes I know that is a bit close to the alt positive terminal for comfort. Only have a screwdriver and some plier at work, Enough for battery post and tighten down a bit. Seems to be ok for now.





08/1986 TOYOTA 4RUNNER TRUCK (RN61LG-MSEA)



HOSE, RADIATOR, OUTLET
16572-35060 RADIATOR SIDE
16573-38020 CHAIN COVER SIDE


CLAMP OR CLIP, HOSE(FOR RADIATOR OUTLET NO.1)
96111-10460

CLAMP OR CLIP, HOSE(FOR RADIATOR OUTLET NO.2)
96111-10460 PIPE SIDE
96111-10490 CHAIN COVER SIDE

 

Thanks for sharing this...

 

Follow up.

tightend it down. Was loose. No more coolant loss or drip. I had forgotten to tighten it down all the way. Was going to move it a bit after installing the alt before installing the engine.
i usually mark each torqued faster with a dab of paint.


There was air in the system. Might mean the ecu temp sender was reading cold. Engines been weird for 2000 miles - I felt it used too much gas. 29mpg is realistic though. Might have to bump the 22-re fuel efficiency thread.

Opened the alternator. Needs bearings, has new brush assembly now.
will order inside bearing (which rusted because of the dripping), diode board, regulator and black paint.