Alternator No Longer Charging - Bug in Dash?

[Terbro]

The alternator should not be pegging, check the charging system. When my Battery lamp, alternator and charging system failed through the years the car would run fine until the battery got below 11 v and then sputter and stall about 35 seconds later.

It's pegging, because my voltmeter is set on a 9 volt scale. So since I'm told it should be putting about about 14.5 volts, it should peg high on the meter since it's set to a 9V scale.

But...I am getting suspicious about the alternator. I'm going to tow it to Advanced Auto Parts tomorrow. I think they can test the alternator on the car (easier to tow it than remove the alt.). I have to eliminate the question of whether the alternator is goofin' on me. I know it's producing a charge, but maybe it's putting out some crap too? I don't even know what that means, but I just want to check the health of the alternator (and the battery as well).

 

[Terbro]

I've also seen bad connections at the alternator plug and broken wire inside the plug. Ohm the circuit from the alternator plug back to the dash connector.

Have verified voltage at the connection point of the harness and boost solenoid.

However...while I often go weeks without starting my TR, which has me thinking my battery is fine, it's manufacture date is 4/09. Though I'd be shocked if my battery just said, "Okay, I'm done, right now, I will have it checked out tomorrow along with the alternator. I have a trickle charger, and that charger is getting it to 12 volts regularly still, and the car starts immediately.

But my mechanic says a good battery will last "50-60 miles". I don't presume to think this is a "good" battery, just that it's been capable of holding enough charge to start the car right up after sitting for 2-3 weeks at a time on a regular basis since I've owned it. However...do we think it's normal that with no alternator charge, it won't stay running for more than about 2-3 minutes?

It'll be at 9 volts, and be dying at about 3 minutes after a full charge (i.e., green light) from the trickle charger.

 

[GNRick]

Have the alternator checked by a real shop. Parts stores' testing is not reliable. Or go to one of those shops that does electrical rebuilding/troubleshooting.

 

[GNRick]

Your 8 y.o battery is 3 years past its expiration date, whether you kept it charged or not.

 

[Boost231]

It's pegging, because my voltmeter is set on a 9 volt scale. So since I'm told it should be putting about about 14.5 volts, it should peg high on the meter since it's set to a 9V scale.

But...I am getting suspicious about the alternator. I'm going to tow it to Advanced Auto Parts tomorrow. I think they can test the alternator on the car (easier to tow it than remove the alt.). I have to eliminate the question of whether the alternator is goofin' on me. I know it's producing a charge, but maybe it's putting out some crap too? I don't even know what that means, but I just want to check the health of the alternator (and the battery as well).

Why would you set your volt meter to 9 volts when you're trying to test a 14+ volt system..

Sent from my SM-G935T using Tapatalk

 

[TurboBuRick]

For now remove the Caspers field fix. That's one less thing in the mix.

Plug in the 1 wire connector on the alternator. Turn the key to on position. Do you have a volt light on the dash?
No volt light = not going charge. In this case there is either bad connection between bulb socket and the alternator or the bulb is blowen.
Volt light on = should charge

If you start the engine and the volt light stays on, replace the alternator.

Rick

 

[turbo nasty]

http://www.installationinstructions.com/FYI/alternator_charging_tech.pdf

 

[Terbro]

I know I disappear on this thread (and other threads) for extended periods of time. That's because I'm either on a budget or get easily frustrated. In this case, shortly after my last post, I towed (I own a tow truck now, fortunately) the TR to the local Advanced Auto and the in-car test revealed that the battery wasn't charging well and the alternator wasn't charging. That's where I left it until today.

Today, I pulled the alternator and had it bench tested. The guy at Advanced Auto seemed like he knew what he was doing, but after attempting to run the test, which didn't progress to spinning the pulley wheel (results being "bad ground"), I decided I wanted another opinion. So I took it to O'Reilly's and though the older guy seemed more knowledgeable, and the test machine (different model or brand of bench test machine) did spin the wheel for about 5 seconds, the results were the same - "bad ground".

So I'd say that's pretty conclusive...an in-car test and two bench tests, essentially all pointing to the alternator. So...a *new* AC Delco unit has just been ordered a few minutes ago through Rock Auto.

 

[GNONYX]

I know I disappear on this thread (and other threads) for extended periods of time. That's because I'm either on a budget or get easily frustrated. In this case, shortly after my last post, I towed (I own a tow truck now, fortunately) the TR to the local Advanced Auto and the in-car test revealed that the battery wasn't charging well and the alternator wasn't charging. That's where I left it until today.

Today, I pulled the alternator and had it bench tested. The guy at Advanced Auto seemed like he knew what he was doing, but after attempting to run the test, which didn't progress to spinning the pulley wheel (results being "bad ground"), I decided I wanted another opinion. So I took it to O'Reilly's and though the older guy seemed more knowledgeable, and the test machine (different model or brand of bench test machine) did spin the wheel for about 5 seconds, the results were the same - "bad ground".

So I'd say that's pretty conclusive...an in-car test and two bench tests, essentially all pointing to the alternator. So...a *new* AC Delco unit has just been ordered a few minutes ago through Rock Auto.

You could also rebuilt that alternator and save a couple of bucks

 

[mikestertwo]

I got rid of the dash bulb issue by using a 3 wire connector on the alternator regulator. There are 3 connections. F=field, S=sense, L=lamp. Run the "F" wire to switched ignition power "S" to the junction point at the fuseable links "L" to the lamp in the dash. This way the alternator will still charge even if the connection to the lamp in the dash opens or the lamp goes bad.

 

[Terbro]

You could also rebuilt that alternator and save a couple of bucks

I was thinking the same thing. Wouldn't want to attempt it myself, but called/contacted 2 or 3 local guys on CL asking for quotes. They didn't get back to me quick enough, so I pulled the trigger on a new (not reman'ed) AC Delco unit. I haven't skimped on anything with my TR, and feel like I'd be gambling with a rebuild.

Yes, this was 30 years ago, but I went through 6 (SIX) reman'ed alternators on my first car ('69 Datsun 510) when I was a teenager over the course of only a few months. They were only lasting a few weeks before failing. I eventually found an Auto Electric shop to rebuild it and didn't have a problem after that. I guess my point is...with certain things - I'd rather pay a bit more and consider it a non-variable for several years.

Rock Auto's total price with the 5% discount + shipping was $98.xx. Not bad for *new* genuine AC Delco. My local auto parts stores were quoting me $121 ($130 w/tax) for reman'ed off brand (AC Delco not available).

 

[Terbro]

Progress, insofar as at least by way of the field fix harness, it's now charging.

I installed the new alternator, and...no volts light, no charging. Very bummed.

About a 1/2 hour later, with some brain activity, I wondered if maybe now the field fix harness would now work. Being that the old alternator was confirmed to have a bad ground, *and* I discovered that the circuit board on the back of the gauge cluster looked pretty beat up (see pic), I surmised that I have two problems, and only fixed one. So I plugged the field fix harness into the alternator (still connected from when I originally installed it a couple months ago). Charging! So as the way it looks from the pic, the torn circuits are responsible as well.

Okay then...I'm on the road, enjoying the TR for the first time in a few months. However, immediately notice that my new speedo cable isn't working. Long story short, I've determined that the issue appears to be a bad speedo gear at the trans. I kept the cable connected at the trans, with the gauge cluster removed, and it's not turning.

So, I need a new gauge cluster, and a new speedo gear. In talking with a local trans shop, I'm told there's a "speedo gear", and a "driven gear". Advance Auto has an orange one and a red speedo gear, one of which is 19 tooth and the other 20 (forget which is which). But on the trans section of this forum, I read talk of 30 tooth gears. So I'm confused which I need.

And I'm confused as to whether I can replace it myself, whether I need the internal speedo gear or just the driven gear. The external sounds like a quick r&r job, the other, according the trans shop guy, requires dropping the pan and he wants $100 in labor.

 

[GNRick]

I think it's a drive gear and a driven gear. One is blue and one is orange. The one connected to the speedo cable is easy to remove. They have plastic teeth and get worn down. I think you want the blue one, which the speedo cable connects to.