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Discussion Starter · #1 · (Edited)
Charging system issues

replaced or checked:

Starter
Solenoid
alternator
4 different batteries have the same effect, work ok in other rides

Maintenanceperformed
redid main ground, added grounds
cleaned up former owners cheesedick wiring.

Only thing added

2 e-fans, at first key on and now switched.
(now that they are switched never have to run them on freeway, and only intermittently in-town)
Believe the former owner pulled t-stat, as rig just does not get hot.

Until Yesterday, when I redid the main three wires that go from the solenoid on inner fender to the alternator, it wouldn't show more than 13 volts on a good day, and less on most days.

If I freeway drove, it would charge enuff to restart but it was a struggle, hence the thoughts that it was grounding pronblems, solenoid, starter, etc.

Replaced the solenoid as it fried one, had AZ and CSK both bench test starter, 5-6 times in a row, and it passed.

Then I started looking at wiring, when BOTH alternators bench tested pass, and rig tested fail, weak at best-recommending replacement.

Found the Solenoid wire to alternator thing I previously mentioned, the 2 thick wires and little yellow (exciter?) wire that run from the back of the alternator to a fusible link that connects to the solenoid, well at that eyelet on the solenoid side of the fus. link, it (the wires) were twisted together, and then like two green with corrosion strands of wire communicated the power from the solenoid to the battery.

Eliminated the fusible link (temporarily, I know it is there for a purpose) ran all three wires into a new copper eye, connected to the solenoid, voila! voltage gauge reads like it should, ran back to AZ and had another "in the rig and running" charging system test done, and the whole thing passed with flying colors.



Until today, it runs correctly half the time, showing the appropriate amount of voltage on the gauge, fans on or off, and it runs below par the other half of the time, just not charging the battery enough to start if it has to crank for more than 2-3 seconds.


Where do I fricking turn to now?

Grounds are clean, alternator tests out, alternator wiring that was f-ed is good, scroll back to the top for all parts i have tested and replaced, or tested and am still running......

Rig in story is a 1987 Bronco EFI 4.9, and Manual trans.
 

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Got a good body to motor ground? Some newer rigs are really fussy about that. Seems like you have covered most everything. Mght try pulling the neg cable off the battery and put a test light between the cable end and battery post. If it lights up-you have a drain going on. Then start pulling fuses to disconnect systems until the light goes out. That system will be your drain. Might help narrow it down. Good luck.
 

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Discussion Starter · #3 ·
Yeah, its good, might add another, have checked for parasitic loss and found nothing, will check again.......
 

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Discussion Starter · #5 ·
Both alternators are internally regulated, so in theory if they check good, the regulator is good,right?

Think this Bronco was born as an externally regulated unit, and some one converted it over to internal, which is why the wires to the alternator aree spliced, although I have cleaned it up, I think the ultimate solution will be to rewire what has been splced.

Gonna amp the wire size up on all of it, #00 for main grounds, and power to starter, etc.
 
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