Electrical Demons

[cateringroadie86]

The over drive on my bronco will turn off and on by its self. It will do this randomly while I am driving or when I touch the break pedal. The break pedal will turn the over drive off and on with just the slightest tap when it does, no serious amounts of pressure are necessary. Also on several occasions over drive will turn Off on it own and I am unable to turn it back On by any means. Finally on ONE occasion while in park with my engine running my over drive OFF light flashed off and on for a solid 30 seconds to a full minute....

Any Ideas whats maybe causing this, or possible solutions?

A new alternator (free of charge, under warranty) seems to have fixed my over charging issue... alternator bench tests do not test the regulation of voltage, only the charging apparently.

 

[AdamDude04]

How do you know the truck is overcharging?

I thought mine was overcharging.. my volt meter was reading 21 volts while running!! Turns out it was a bad battery in the volt meter...Drove my truck 1200 miles straight, then another 1000 miles straight a few days later.. truck runs fine, and battery cranks the truck like normal and nothing has fried...

 

[cateringroadie86]

My volt meter goes past 18 to where 20+ would be and my battery light comes on in the dash cluster. My headlights & instrument lights all get brighter and you can her the RPM's increase on the blower motor.... my volt meter usually reads around 12 when running normally

 

[50joe]

Sounds like the regulator is goin on you. Could be either internally or externally regulated. If its external, I THINK the regulator would be mounted on the inner fender by the battery. But dont quote me on that. My mustang did the same thing, and a new voltage regulator did the trick.

 

[Elmo]

Overdrive or actually the torque converter is supposed to unlock with application of the brake. As for the flashing it may be a code like the check engine light flashes.

 

[cateringroadie86]

well, no solution yet. I have an internal voltage regulator it seems. Cannot locate an external one. My alternator is good. Tried replacing starter solenoid, that didnt fix it....

I have a optima red top battery... Could the battery be a source of the problem?

 

[broncosam43]

well, no solution yet. I have an internal voltage regulator it seems. Cannot locate an external one. My alternator is good. Tried replacing starter solenoid, that didnt fix it....I have a optima red top battery... Could the battery be a source of the problem?

from what your saying it would lead me to belive that you might have bad conncetions at your battery (dirty terminals) also how old is your battery? if your battery is no good it would cause some alternator charging sistem problems. I know i had a bad diode in the alternator on my 94 bronco, it caused it to have a voltage raise with engine rpm, lights would really dim at idle also it back fed into the pcm causing hard shifting (e4od trans) also try fully loading your alternator turn everything on and see what your voltage does mine jumped all over the place hope this helps

 

[cateringroadie86]

the battery is only 3 months old... If I turn on all my lights and accessories my voltage is normal until my RPM's get to a certain point anywhere from 3,000 to 4,000 the voltage will jump up past 18 and the battery light comes on...

 

[Seabronc]

Well, I'd guess that the regulator mounted on the alternator is bad. It is mounted right where the (+) post is located. The new regulator has a pin in it to hold the brushes back while installing it. Once installed remove the pin. You should be able to get the new regulator at an auto parts supply. I prefer to deal with a real mechanic's supply rather than the chain store auto suppliers.

Good luck,