What have you done to your square lately??

[Grit dog]

That's why I avoid Auto Zone.

I wish the issue was just with the “cheap” parts/stores, but it’s not.
Several years ago we sat in a Napa parking lot changing out Napa reman alternators. Short story each had something wrong. #1 worked but was damaged. #2-4 didn’t even work. Ended up back with #1 to get us home and returned it the following week for one that wasn’t messed up.
Currently no pun intended I have another Napa reman on the K20. Has maybe 50 hrs on it and I suspect it’s causing the parasitic current draw in the truck.

 

[Travlr]

I wish the issue was just with the “cheap” parts/stores, but it’s not.
Several years ago we sat in a Napa parking lot changing out Napa reman alternators. Short story each had something wrong. #1 worked but was damaged. #2-4 didn’t even work. Ended up back with #1 to get us home and returned it the following week for one that wasn’t messed up.
Currently no pun intended I have another Napa reman on the K20. Has maybe 50 hrs on it and I suspect it’s causing the parasitic current draw in the truck.

Napa stores are independently owned. They have a lot more flexibility than corporate owned stores. They have some choices, even from the NAPA system. I've seen them buy questionable product at times... and bear the consequences.

 

[Grit dog]

It is an 87, 350 TBI.

Also there’s no mechanical fuel pump. And if there is, that is not right.
I know it always seems tough for you to get time to diagnose or work on the truck.
This however is all super quick and easy to check, and honestly sounds like the alternator could be the cause of both issues.
Order of OPs
1. Fully charge battery
2. Test for parasitic loss
3. Unplug alt if yes to above and see if it’s the culprit.
4. If yes to 3, replace alt and see if it cures the running quality issue. If it doesn’t, it’s not wasted $ because it was bad anyways.
5. If no to 3, start vehicle with fully charged battery. Once it runs rough, shut off, unplug alt and restart and see if it runs good.
Maybe @Ricko1966 can chime in, if this is a solid plan.

 

[mxer147]

Bad plug? Bad plug wire? Maybe just loose?

Try running it at night parked with your lights off to see if it’s arcing around the cap and plug wires.

 

[JamesSam]

Also there’s no mechanical fuel pump. And if there is, that is not right.
I know it always seems tough for you to get time to diagnose or work on the truck.
This however is all super quick and easy to check, and honestly sounds like the alternator could be the cause of both issues.
Order of OPs
1. Fully charge battery
2. Test for parasitic loss
3. Unplug alt if yes to above and see if it’s the culprit.
4. If yes to 3, replace alt and see if it cures the running quality issue. If it doesn’t, it’s not wasted $ because it was bad anyways.
5. If no to 3, start vehicle with fully charged battery. Once it runs rough, shut off, unplug alt and restart and see if it runs good.
Maybe @Ricko1966 can chime in, if this is a solid plan.

Thanks @Grit dog Todd, this definitely seems achievable, even by me.
I am chomping at the bit to try some things especially now knowing, potentially, that this could be the alternator.
Being the lame shade tree dude, I do not have a probe tester light, and it is 30° outside here currently. Zero stores have a probe light tester in stock. Likely I will be enlisting help from my uncle in law with his mechanical equipment. Waiting on the snow to melt and "cannot wait" to see if the battery is being leached, and if the alternator is the culprit. It seems to stack up as the truck will perform but not to full capacity. I have definitely, accurately self diagnosed alternators beginning to die off in my current daily( CRV) as well as previous daily drivers: 06 Sonata V6, and Buick Century Custom, all with similar ailments.

 

[Radiohead]

That's why I avoid Auto Zone.

Stay outta the zone, Auto Zone.

And Napa. Don't get me started.
Which is usually what happens, lol.

Had decent enough luck with O'Reillys so far, but now I've jinxed that.

Oddly enough, here at the radio ranch, Rock Auto has been the winner, even with the hassles of waiting. But they've make good with return shipping on defective products. I suppose it's a crap shoot anywhere these days, huh.

Being the lame shade tree dude, I do not have a probe tester light, and it is 30° outside here currently. Zero stores have a probe light tester in stock.

Heres a down and dirty trick for you. Take an 1157 lamp, disconnect the battery. With key off and door closed, take bulb tip and put it on the negative terminal while simultaneously touching the battery cable to the brass bulb shell. Any draw will illuminate the lamp. Who needs a fancy test light?

 

[Travlr]

Stay outta the zone, Auto Zone.

And Napa. Don't get me started.
Which is usually what happens, lol.

Had decent enough luck with O'Reillys so far, but now I've jinxed that.

Oddly enough, here at the radio ranch, Rock Auto has been the winner, even with the hassles of waiting. But they've make good with return shipping on defective products. I suppose it's a crap shoot anywhere these days, huh.

Heres a down and dirty trick for you. Take an 1157 lamp, disconnect the battery. With key off and door closed, take bulb tip and put it on the negative terminal while simultaneously touching the battery cable to the brass bulb shell. Any draw will illuminate the lamp. Who needs a fancy test light?

It's my experience that NAPA once had the best counter personnel, people that "knew" **it, and if they didn't they knew where to look. But the advent of computers and them throwing their books away has led to a lot of counter help that has no knowledge except how to use a computer.

 

[Grit dog]

Stay outta the zone, Auto Zone.

And Napa. Don't get me started.
Which is usually what happens, lol.

Had decent enough luck with O'Reillys so far, but now I've jinxed that.

Oddly enough, here at the radio ranch, Rock Auto has been the winner, even with the hassles of waiting. But they've make good with return shipping on defective products. I suppose it's a crap shoot anywhere these days, huh.

Heres a down and dirty trick for you. Take an 1157 lamp, disconnect the battery. With key off and door closed, take bulb tip and put it on the negative terminal while simultaneously touching the battery cable to the brass bulb shell. Any draw will illuminate the lamp. Who needs a fancy test light?

That’s cool. How much amperage you figure it takes to make it glow?
I’ve done that before but it was a longtime ago with a test light and it was a large draw. I’m accustomed to using a multimeter so I can see something quantitative. On an old car like these squares they should be ideally very close to 0. My 78 draws like 3mA, the old jeep is 0, the 86 is pulling about 40mA from somewhere and I think its the alternator he slapped in a couple years ago because an old chitty “remanufactured” battery that came in it worked for a couple years with no keeping up with a charger when sitting for months at a time. Then sometime between then and before the new stereo it started leaking amps out of the battery to somewhere and the alternator was the only electrical thing touched iirc.

 

[Grit dog]

It's my experience that NAPA once had the best counter personnel, people that "knew" **it, and if they didn't they knew where to look. But the advent of computers and them throwing their books away has led to a lot of counter help that has no knowledge except how to use a computer.

Except I’d say there’s a 90% better chance not getting a dummy who is of little help at Napa than it is at the Vato Zone or OhReallys.

 

[Radiohead]

It's my experience that NAPA once had the best counter personnel, people that "knew" **it, and if they didn't they knew where to look. But the advent of computers and them throwing their books away has led to a lot of counter help that has no knowledge except how to use a computer.

That, and the fact that the parts quality has been hit or miss on a growing portion of the product lines. An unfortunate by product of the race to the bottom. I can get the same chinesium at lower prices almost everywhere, hence the vato zones of the world.

That’s cool. How much amperage you figure it takes to make it glow?
I’ve done that before but it was a longtime ago with a test light and it was a large draw. I’m accustomed to using a multimeter so I can see something quantitative. On an old car like these squares they should be ideally very close to 0. My 78 draws like 3mA, the old jeep is 0, the 86 is pulling about 40mA from somewhere and I think its the alternator he slapped in a couple years ago because an old chitty “remanufactured” battery that came in it worked for a couple years with no keeping up with a charger when sitting for months at a time. Then sometime between then and before the new stereo it started leaking amps out of the battery to somewhere and the alternator was the only electrical thing touched iirc.

Any draw will light up, but draw in the milliamps will need a little cover of darkness. A meter like you describe takes that issue away.

 

[Grit dog]

Thanks @Grit dog Todd, this definitely seems achievable, even by me.
I am chomping at the bit to try some things especially now knowing, potentially, that this could be the alternator.
Being the lame shade tree dude, I do not have a probe tester light, and it is 30° outside here currently. Zero stores have a probe light tester in stock. Likely I will be enlisting help from my uncle in law with his mechanical equipment. Waiting on the snow to melt and "cannot wait" to see if the battery is being leached, and if the alternator is the culprit. It seems to stack up as the truck will perform but not to full capacity. I have definitely, accurately self diagnosed alternators beginning to die off in my current daily( CRV) as well as previous daily drivers: 06 Sonata V6, and Oldsmobile Century Custom, all with similar ailments.

As mentioned if it’s a decent size draw you can see it with a light bulb. But for more accurate results a multimeter is preferred. Christmas in a couple weeks you should ask for a digital multimeter.
It’ll be good for the rest of your life.
Mine is old enough it’s a Sears craftsman made by fluke (been alotta years since Sears wast Kmart crap, are they even in business anywhere anymore?)
This should be in the rant thread. Used to be able to go to the mall and shop for man stuff like tools and chainsaws at sears. Now it’s umm…Nevermind lol

 

[Radiohead]

Also, you can find spark plug wire leaks in daylight by misting the region with a water sprayer bottle.

 

[Ricko1966]

Thanks @Grit dog Todd, this definitely seems achievable, even by me.
I am chomping at the bit to try some things especially now knowing, potentially, that this could be the alternator.
Being the lame shade tree dude, I do not have a probe tester light, and it is 30° outside here currently. Zero stores have a probe light tester in stock. Likely I will be enlisting help from my uncle in law with his mechanical equipment. Waiting on the snow to melt and "cannot wait" to see if the battery is being leached, and if the alternator is the culprit. It seems to stack up as the truck will perform but not to full capacity. I have definitely, accurately self diagnosed alternators beginning to die off in my current daily( CRV) as well as previous daily drivers: 06 Sonata V6, and Buick Century Custom, all with similar ailments.

Every parts store in America has a simple incandescent test light,and that is what you need. Even lacking that an old school incandescent 194 bulb unbind the wire loops on the bottom twist lengths of wire onto the loops. If you want to get fancy put alligator clips on the other ends. Unhook the battery negative, 1 minute,hook your light 20 seconds, did the light light yes/no you checked parasitic in 1.3 minutes.

 

[Ricko1966]

As mentioned if it’s a decent size draw you can see it with a light bulb. But for more accurate results a multimeter is preferred. Christmas in a couple weeks you should ask for a digital multimeter.
It’ll be good for the rest of your life.
Mine is old enough it’s a Sears craftsman made by fluke (been alotta years since Sears wast Kmart crap, are they even in business anywhere anymore?)
This should be in the rant thread. Used to be able to go to the mall and shop for man stuff like tools and chainsaws at sears. Now it’s umm…Nevermind lol

There's a reason I told him to use an incandescent bulb. I'm specifically looking for a bad alternator diode. Not just a parasitic draw. The bad diode would explain a ton of things. If we start testing with meters,power probes LED lights things that will read firefly farts we are making things more complicated. Not bagging on you just explaining my train of thought. At work before I've caught the younger crowd check for power to something with their fancy LED red/green test light. Decide there was power change a fuel pump or whatever. And then they are confused when it doesn't fix the problem,the problem is the circuit has voltage but can't supply the amperage. So anyway have a great day and remember sometimes there's a time and place for those stupid old incandescent bulbs.

 

[Grit dog]

There's a reason I told him to use an incandescent bulb. I'm specifically looking for a bad alternator diode. Not just a parasitic draw. The bad diode would explain a ton of things. If we start testing with meters,power probes LED lights things that will read firefly farts we are making things more complicated. Not bagging on you just explaining my train of thought. At work before I've caught the younger crowd check for power to something with their fancy LED red/green test light. Decide there was power change a fuel pump or whatever. And then they are confused when it doesn't fix the problem,the problem is the circuit has voltage but can't supply the amperage. So anyway have a great day and remember sometimes there's a time and place for those stupid old incandescent bulbs.

I wasn’t suggesting otherwise. I know it works but only on bigger draws. But idk how much. I’m not a mechanic by trade , I’m an enginerd who builds **** and like working on cars so I look at it quantitatively.
I’m intrigued, what you mean by using an incandescent bulb specifically to diagnose a bad diode. What does it do different than any other parasitic draw?
Love learning new old tricks.