Alternator HOT

[External]

I replaced my external voltage regulator cause it went out. And replaced the alternator -while I was there. Same alternator, plugged right up. Things are going fine.
I reach into the engine bay today and its warm it not hot to the touch.
What is going on?
I already know I need to change this rats nest of a wiring harness I have.
I'm trying to get my engine timed correctly so that I can ask other questions of power loss.
These two things might be related. I am at my breaking point.
As much as I despise car dealers I dislike mechanics even worse.
Besides the crazy amount of money they want.
But it just seems like every thing I fix, two things break.
I have always wanted one of these trucks, but now that I am older, they are older too.
Gripe grumble complain. And so on.

[Stocker]

Since I am not a mechanic by any stretch of the imagination, I cannot offer any useful advice.

Gotta agree with Killer Bee though -- good luck. Maybe a thick-skinned mechanic will help you.

[External]

So I already knew I had a timing issue. After watching hours of videos and reading posts on here I ran through the whole finding top dead center. Pulling my distributor and turning the oil pump shaft so that the distributor would line up properly with #1. And put it all back together with new plugs and wires. Smiling the whole time like I had these beast beat. Go to fire it up, and did just that.
Backfire and my carb is on fire. But not nearly as hot as I am.
I hear that if the distributor is firing on #6 it will backfire and cause this. I pull the cap and nope, its pointing right at #1.
So i try again.
Now whatever is wrong with the dern alternator getting hot has drained my brand new expensive battery.
Broke out the battery charger and am just gonna go fold the laundry. Or mow the lawn.
Side note, this forum family is better than therapy. Thank you for listening.
I'll either figure or it will be nice to look at in the garage.

[Ganty101]

Have you checked the voltage out out of the alternator? Mine was getting hot and it was kicking out 18+ volts. The wiring and battery also got hot!

[External]

No sir. Which wires do I check? There are three on the back of the alternator. Four on the regulator.

[Ganty101]

Just get a volt meter (make sure it’s good for higher voltage) and possibly a friend to run the truck while you test the voltage. Then just run the truck and do a voltage check the battery terminals. Should be 13.7 volts (if I remember rightly) there abouts anyway. Mine was normal on idle but when I reved it up the voltage went up to 18 or so. Not good! Good luck!

[Killer Bee]

Originally Posted by Stocker

Since I am not a mechanic by any stretch of the imagination, I cannot offer any useful advice.

Gotta agree with Killer Bee though -- good luck. Maybe a thick-skinned mechanic will help you.

got thick enough skin, just ain't dealing out free professional advice to only to have my profession insulted

after 30 something years I've heard it all and it still makes me laugh..

learned to ignore the ones that think I make too much money for solving their problems

which btw is an easy one and he's getting warm

[Ganty101]

Originally Posted by Killer Bee

got thick enough skin, just ain't dealing out free professional advice to only to have my profession insulted

after 30 something years I've heard it all and it still makes me laugh..

learned to ignore the ones that think I make too much money for solving their problems

which btw is an easy one and he's getting warm

I’m also a mechanic, and while it’s east to adopt that attitude we are all friends here. Plus there are some shady people acting like mechanics and charging too much!

On my truck the regulator was no good so I swapped it out for a vauxhall cavalier 1989. Off a 1.3 I think. Has the reg built in and only too a little filing on one of the mount points to fit my truck. Not bad, fully reconditioned for £30!

[External]

Ok you are TOTALLY correct sir. What I should have said was,
The people I have had done business with in the past who called theirselves mechanics treated me badly. I have not had good experiences with some shady mechanics in my lifetime. I really do apologize and now that I calmed down and re read my ugly post you have every right to be upset. Please overlook my frustration and ugly words.
I thought I knew what I was doing. And I guess I don't. A part changer I am I suppose.
Again, I'm sorry.

[Ganty101]

Originally Posted by External

Ok you are TOTALLY correct sir. What I should have said was,
The people I have had done business with in the past who called theirselves mechanics treated me badly. I have not had good experiences with some shady mechanics in my lifetime. I really do apologize and now that I calmed down and re read my ugly post you have every right to be upset. Please overlook my frustration and ugly words.
I thought I knew what I was doing. And I guess I don't. A part changer I am I suppose.
Again, I'm sorry.

I wouldn’t beat yourself up, I hear a lot of people with horror stories of garages they’ve been to. I’ve been lucky to grow up with my dad and step dad both both mechanics and doing the same myself. Though I must say I’m more of a parts fitter than a mechanic. I can diagnose a problem and can replace the part but most parts aren’t servicable anymore. Kinda why I wanted a truck. To learn more! That’s all any of us can hope for.

Anyway back to the topic, make sure you post any findings when you do a the charging voltage check. We can see where to go from there! It’s late over here in old blighty, I’m off to bed.

[webfoot]

I had a brand new external regulator and alternator, the VR still didn't work and overcharged the battery.

For not much money I got the pigtail and converted to an internally regulated "12SI" alternator, no more problems.

[External]

Maybe I should also have said that I found the alternator Hot after sitting in the garage over night. Not running.

[Stocker]

Originally Posted by External

Which wires do I check? There are three on the back of the alternator. Four on the regulator.

Originally Posted by Ganty101

Just get a volt meter (make sure it’s good for higher voltage) and possibly a friend to run the truck while you test the voltage. Then just run the truck and do a voltage check the battery terminals. Should be 13.7 volts (if I remember rightly) there abouts anyway. Mine was normal on idle but when I reved it up the voltage went up to 18 or so. Not good! Good luck!

Agreed on checking voltage at the battery. But since you asked, you can also check the fat red wire (under the black rubber boot) on the back of the alternator.

I had overcharging problems last year and burned up some wiring. I was totally lost and got great advice from some terrific board members.
An internally regulated alternator for a 1985 Buick Riviera, along with some minor re-wiring, fixed the problem.
Here's the thread detailing my misery if you're interested: http://67-72chevytrucks.com/vboard/s...d.php?t=772236

[Stocker]

Originally Posted by External

Maybe I should also have said that I found the alternator Hot after sitting in the garage over night. Not running.

Just guessing, that alternator has an internal problem. The red wire has 12V from the battery, maybe something is shorted to ground internally. It should not get hot just sitting there.

[Steeveedee]

You have at least one bad diode in the alternator. It's defective, take it back. I was a mechanic for many years, and have seen this many times. Being a rebuilt unit means nothing. I couldn't get the rotor out of my alternator (it only had a noisy front bearing, which I was going to replace), so I replaced it with a rebuilt and it killed the battery DEAD. I didn't know what the problem was until I realized it was taking a long time to charge and laid my hand on the alternator and it was warm. It was still warm when I got to the parts store, so they knew I had it right. But they know I know what I'm doing, so they exchanged it, no questions.

[External]

I will take it back. It is good to know you all are here!
I'll report just as soon as I get it replaced.

[rpmerf]

On your timing issue, remember that the crank will spin twice for every time the engine spins once. There are a couple ways to figure out if you are at TDC or 180* out.

You can watch the valves. When you see the #1 intake valve close, the next time the balancer lines up with 0, you will be at TDC.

Put your thumb over the spark plug hole while someone spins the crank. While the balancer is getting within 180* of 0*, compression will build pressure, exhaust will not.

A second thing to remember is that even if the rotor is pointed at the right place, the cap may be off. Line up the #1 terminal with the cap, maybe advance it a little. and that should be good enough to get it started.

[External]

Thanks! I was 180° off. I got it started and used that new timing light.
It's a good ways before the tab. I'd guess at least 20° or more.
But that is where it runs the best. This is without vacuum advance.
I have not hooked up the vacuum yet.

[rpmerf]

There is a debate as to whether the vacuum advance should be connected to ported vacuum (as it was from the factory), or manifold vacuum. The difference is whether or not it provides advance at idle. I prefer manifold, so it provides advance at idle.

In setting the timing, there are 3 things you really care about.

All in timing. This is where your mechanical advance is fully advanced with the vacuum advance disconnected. Rev it up until it stops advancing. Should be about 36*.

All in RPM. This is the RPM it stops advancing at. Should be around 2500-3000 RPM. You want it to come is as soon as possible without pinging. You will need a distributor advance kit if you want to change this. It will come with weights and springs.

Vacuum advance. This advances the timing at part throttle and cruise. Should be around 10-12*. After you have your distributor set, note the base timing at idle. Should be around 18* (It's ok if it's not). Plug in the vacuum advance. It should add 10-12*. How you change it depends on the advance. Factory ones use a limiter plate. Set this to set the starting point and limit movement. Once you are done, you will need to reset your base timing back to where it was. Aftermarket ones can be adjusted with an allen wrench. You want your vacuum advance to add as much as it can without knocking or pinging. The real test is part throttle on a cold engine. With the choke on, the engine runs richer and needs less advance.

Limiter plate:
https://www.summitracing.com/parts/crn-99619-1

If setting your timing makes it harder to start, you will want to back it off a few degrees. Since the spark is igniting so far before the piston reaches TDC, it can make it hard to start.

[sloGMC]

There is a debate about where vacuum advance should be connected, but it is a function of whether or not you care about emissions. Set your initial timing with vac. advance disconnected, then connect the canister to full manifold vacuum (if you want better efficiency), and lower your idle speed again with the idle speed screw on the carb. This super chevy article has a good write up. http://www.superchevy.com/how-to/add...gnition-timing

[garyd1961]

Sounds to me like your voltage regulator is stuck or either you have the wrong part altogether.

[External]

Thanks for the info sloGMC. I'll give it some study.

Now that I have it driving I'll take it to the parts store I purchased the regulator and alternator from, have them do a check. Both parts purchased were the ones listed for original parts for my truck.
Well, I notice that when looking up parts it asks for VIN number.
Mine starts with a C. It's always asking for a J or a H or something.
What's up with that?

[rpmerf]

I am thinking more about your generator / voltage regulator situation. I wouldn't be surprised if the people at the parts store couldn't test for this. GM stopped using external voltage regulators in ~1974.

I am trying to remember the purposes of each of the wires on the regulator. Not positive the function of F (dark blue) and 2 (white). They both output to the generator. Might try and figure out where these should be at with the key turned off. 3 gets battery voltage, and 4 gets keyed power through the light. You could verify #4 (brown) stops getting power when the key is turned to off. Could disconnect the voltage regulator to see if the generator alone is discharging the system.

I ditched my generator and external voltage regulator after blowing through 2 voltage regulators in a year and seeing the price of a new voltage regulator. The first one overcharged, and blew the 30 amp fuse on my battery. The second one drained my battery over night. Got a 78 amp alternator for an 85 Buick Riviera 5.0, rewired it (you can use jumpers), and haven't had any issues since.

EDIT:
The R will be hot at all times while the F will only be hot when the ignition is keyed on.
Source: https://alternatorparts.com/what-are...nator-faq.html

Might try and verify this elsewhere.

Another thought: Swap in your old generator to see if the battery still dies. That could eliminate the new generator as a source of the issue.

[External]

I returned the bad alternator for a new rebuilt one.
Things went back to normal! I will learn how to use a volt meter. I can see it is necessary.
Thank you all for your help.

[Steeveedee]

Excellent! It's really annoying when replacement parts are bad out of the box.