Lost Power

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Petros
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Posts: 11941
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Lost Power

Post by Petros »

one wire off the back of the alternator goes directy to the battery voltage without going through a fuse, this is the heavier output wire. If it is melting it might mean that something is connected wrong at the battery (are the terminals on correctly?) or there is a short somewhere before the fuse box. the other smaller wire also should have 12 volts to it, I think it does come from a fused sourse, this is the armature wire that energizes the field windings in the alternator to 'turn on' the alternator when charging. If this is the one that is melting you have trace it back to where it goes into the fuse box (it goes into a harness so you will have to use the color code on the wire). It could have a short internal to the wire bundle as well, this is not normal but on a car this old anything can happen, it happened on my '84.

You should have internal voltage regulator on your alternator for that year, but if you have an external voltage regulator you should also inspect those contacts as well.

Good luck
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
jann_e_gunn
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Posts: 28
Joined: Sun Dec 01, 2013 4:14 pm
My tercel:: 1985 tercel 2wd

Re: Lost Power

Post by jann_e_gunn »

It seems it was an internal short on the alternator. I shook the hey out of all the wires and couldn't get anything. The alternator was older than I know and had been rebuilt a few times and a new nor was only $40 so I opted to put it in. Everything serms to be going okay. I'm gonna keep messing with the wiring to mKe sure there is not another short. Hopefully that will do it!
jann_e_gunn
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Posts: 28
Joined: Sun Dec 01, 2013 4:14 pm
My tercel:: 1985 tercel 2wd

Re: Lost Power

Post by jann_e_gunn »

I appreciate all of your input!
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Petros
Highest Ranking Member
Posts: 11941
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Lost Power

Post by Petros »

wow, in the alternator? that is good to know. Usually they just go dead. I supposed it is possible if the internal insulation that separates the 12 volt parts from the housing breaks down.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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