First day out in 2014 and the light pops on while driving 45. Now it comes on instantly everytime i start it. Power is very low!
First thing is check the molex correct? Then, check the brushes? How do i check the alternato brushes?
alternator light came on. grrrr
- audiocontr
- Posts: 1868
- Joined: Fri May 01, 2009 1:30 pm
- Location: Buffalo NY
alternator light came on. grrrr
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
Re: alternator light came on. grrrr
Section "O" starting at page 9 in the repair manual provides good instruction for R&R and repair and testing of the alternator.
I agree with suspecting the main molex corrector, along with checking battery connections and grounds.
The alternator brushes would not be first on my list unless i ascertained that the alternator is not putting out, especially as the truck just woke from its winter hibernation.
I agree with suspecting the main molex corrector, along with checking battery connections and grounds.
The alternator brushes would not be first on my list unless i ascertained that the alternator is not putting out, especially as the truck just woke from its winter hibernation.
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
- Jimm391730
- Posts: 1456
- Joined: Wed Apr 14, 2004 10:58 pm
- Location: Idyllwild, CA
Re: alternator light came on. grrrr
I agree with Edzz, start with the Molex. Then, in my experience, I'd replace the regulator (~$40) before suspecting the alternator itself. I've seen or heard of open alternator wiring and open rotors in the alternator. While there are ways to test and debug, they are not easy to describe without being at the vehicle.
So first, check to make certain that all wires going into the Molex (from the truck side) have good continuity all the way through the Molex to the terminals on the alternator. If you find problems here, they can cause other problems as well - arcing at the Molex can kill the regulator (and in my case, took out the rather expensive alternator, too). It is easy to overlook or ignore the Molex but many of us have suffered the consequences of doing so.
So first, check to make certain that all wires going into the Molex (from the truck side) have good continuity all the way through the Molex to the terminals on the alternator. If you find problems here, they can cause other problems as well - arcing at the Molex can kill the regulator (and in my case, took out the rather expensive alternator, too). It is easy to overlook or ignore the Molex but many of us have suffered the consequences of doing so.
Jim M.
712W and 710M
712W and 710M
- audiocontr
- Posts: 1868
- Joined: Fri May 01, 2009 1:30 pm
- Location: Buffalo NY
Re: alternator light came on. grrrr
wire on the back of the alternator busted at the molex. fixed.
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
- Jimm391730
- Posts: 1456
- Joined: Wed Apr 14, 2004 10:58 pm
- Location: Idyllwild, CA
- audiocontr
- Posts: 1868
- Joined: Fri May 01, 2009 1:30 pm
- Location: Buffalo NY
Re: alternator light came on. grrrr
Ya thanks much.
The exposed copper oxidized at the crimp and deteriorated. I placed new crimps on all wires. Should be good for another 40 years.
The exposed copper oxidized at the crimp and deteriorated. I placed new crimps on all wires. Should be good for another 40 years.
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
- Jimm391730
- Posts: 1456
- Joined: Wed Apr 14, 2004 10:58 pm
- Location: Idyllwild, CA
Re: alternator light came on. grrrr
Coat the whole terminal with grease (from wire insulation, over the crimp, to the end of the terminal) to protect from corrosion and they will last twice as long.
Jim M.
712W and 710M
712W and 710M
Re: alternator light came on. grrrr
I just had the same thing (charging light stays on) happen yesterday. I'm glad I read this post because I knew the outer side of the Molex was clean but didn't think to check the inside. Took off the engine tin and found the same problem you had - the terminal on the red wire had corroded and the wire had fallen off. Relatively easy fix.
audiocontr - Thanks for posting and leading the way.
audiocontr - Thanks for posting and leading the way.
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
_________
'73 Swiss 710M
'89 Puch 230GE
Re: alternator light came on. grrrr
Because I went through just about the same thing, I wrote down some "good" readings after repair:
Bat 28.20v
DF 9.0 +/- 0.3v
D- 0.0v
D+ 28.46v
Bat 28.20v
DF 9.0 +/- 0.3v
D- 0.0v
D+ 28.46v