So, I've known that the alt on Murphy, the 87 Turbo Wagon, has been going south for some time. The charge on the volt meter would get lower, showing that the battery is losing charge. Then, if I rev the engine, the alt does kick in, but charges at a higher voltage than desired, about 16.5 volts. This last week, it just stopped even doing that. So Friday I got a new alt from Autozone.... and the alt is still not charging. I'm assuming the new one is also bad... Hey, it happens. Is tere anything else I should look for?

Well after my kast reman I will be having all store bought alts tested b4 leaving the store.. Fortunately I found one at the PAP yesterday that I had tested and works properly for less than $15. The only other rhing that may not be working would be the atls trigger but I have only heard of one case that had this problem. How is our battery?

i have picked up about 3 or 4 pick and pull alternators with newer "rebuilt" stickers on them, looking newish. All have been bad, usually voltage regulator allows them to way way overcharge.

Bummer. Just had the new alt checked... It passed. Now will have to look at other electrical issues.

You're definitely having voltage regulator issues, and the EA82 system is externally regulated. I don't remember where the regulator is...but I know it can be replaced.

You're definitely having voltage regulator issues, and the EA82 system is externally regulated. I don't remember where the regulator is...but I know it can be replaced.

 

Hmmm, I always thought the voltage regulator was built into the alt..... Which was one of the differences between a generator and an alternator.

May have found the problem... bad connection at the black fuseable link. The link itself wasn't blown, but one of the terminals was making a bad connection and caused some scoring of the terminal. I filed that and got it clean. Am going to find a new link and see if that will fix things.....

 

UPDATE: Couldn't find a new fuseable link. Put a new terminal end on the burnt one. Now the alternator seems to charge... after I've revved the engine to about 5000RPM. The black fuse is very warm to the touch.... Too much. Will get a new fuseable link housing in the next few days and see if it helps.

Edited October 10, 201015 yr by Sonicfrog

I "know" the ea81 alternator voltage reg is internal. Are you saying the ea82 voltage reg is not internal. That would explain it to me.

You're definitely having voltage regulator issues, and the EA82 system is externally regulated. I don't remember where the regulator is...but I know it can be replaced.

 

Isn't the regulator built into the alt on ea82s? Especially by 87

nope, I'm 100% positive that the EA82s are externally regulated. Most cars are internally regulated (including EJs and XT6s)....so it is weird. I thought EA81s were external too, but I've never owned one, just worked on a few.

 

 

but yea...fusible link would do it too.

If EA82 alternators are swappable with EA81 alternators then they are definitely internally regulated because I know for a fact that EA81 alternators are internally regulated.

 

From the original post it looks like classic failure of the excitor diode in the alternator which is easily replaceable and causes the alternator to fail to kick start, e.g. +12V and -12V which is 0V and a non-charging alternator until you rev the engine. If it is overcharging then yes you also need a new regulator.

nope, I'm 100% positive that the EA82s are externally regulated. Most cars are internally regulated (including EJs and XT6s)....so it is weird. I thought EA81s were external too, but I've never owned one, just worked on a few.

 

 

but yea...fusible link would do it too.

 

Why would the EA81 alt regulator be internal and not the EA82?

 

For what it's worth... The alt in my 89GL has a sticker that says "IC REGULATOR BUILT IN"

And I've never heard of an external regulator except on really old ea81 or maybe just the ones older than that.

any leads on replacement regulators? i would have spares if i had some regulators.

any leads on replacement regulators? i would have spares if i had some regulators.

 

RockAuto has them

 

 

 

Huh....I guess you guys are right. I have always been under the impression that they were externally regulated, but now that I look, I can't find where that came from. . I swear it was in the gauge cluster.....Oh well....I'm an idiot, carry on :-\

Here's an interesting Alternator thing... I'm Prettty sure my regulator is going too... the gauge reads 18amps when the is anywhere above an idle. I pulled the ground wire off the battery to see if the car would die, it revs higher AND the windshield wipers come on! Yes the switch all the way off, I checked because the intermitents are intermitent, sometimes they get left on.

 

What the Heck? weird

The gauge reads volts, not amps. 18v is WAY WAY high, DO NOT RUN IT!!! You'll fry the electrical system.

 

Also, I'll probably start another argument with this. But you should NEVER run with your battery disconnected. Very bad.

I didn't run it , just pulled it off and put it right back on. What do you think about the wipers?

 

Gonna go put the new alt in right now.

Running it with the negative terminal off for a very short time won't hurt anything. I've had a couple very good mechanics tell me to do that to test that my charging system is working.

Running it with the negative terminal off for a very short time won't hurt anything. I've had a couple very good mechanics tell me to do that to test that my charging system is working.

 

I've had some very good mechanics tell me never to do that, and one who had a system mess up from doing that once. Maybe it was already messed up

I don't know .... I'd never do it. I said this would probably start an argument

Haha. It probably has alot to do with how advanced the electrical system is too. The guys that told me to try that knew i had a 75 ford pickup, which has a very simple electrical system. I know it can damage my dads bmw cause the computer is so advanced. So i think it would be fine on an old soob As long as its a very short period of time. They're pretty simple.

Fair enough. I wouldn't do it on a car with EFI. But a car that only has electrical needs for a fuel pump and running the coil is completely different.

I ran the car for a few minutes. While the volt meter on the dash read somewhere around 16v, my more accurate digital volt meter indicated a 13 V charge between terminal. I'm thinking that the resistance on the FL terminal may be causing a false reading on the dash. As of a week ago, there was a 92 Loyale in the bone yard with an intact FL housing. Hope to get that tomorrow and see if that cures the problem. In the mean-time, to be on the safe side I'm not driving Murph until I get this resolved.

 

PS. I didn't expect this thread to generate the response it has. It's cool when that happens! Wish my blog would do that more often.