Keep getting bad alternators??? On #4

[pbrstreetgang]

On 4th alternator on 78 Chevy k10 with factory wiring

All connections / grounds gone through and cleaned
Exciting wire is getting 12v with motor not running
New battery
New 2 gauge battery cable to starter

Im thinking battery light in gauge cluster is not doing its thing but mechanic says alt not charging but how can I get 4 bad ones?

Could something be burning them up?

 

[Radiohead]

Are they all the same brand/rebuilding? Which one?
Cardone maybe?

 

[fast 99]

Power on the battery terminal at Alt?

 

[SirRobyn0]

Are they all the same brand/rebuilding? Which one?
Cardone maybe?

That's pretty much what I was going to say

@pbrstreetgang Get a quality NEW alternator, try really hard to avoid remans if at all possible. These trucks have a super simple charging system, and most of it is inside the alternator case. I'm headed out the door of the shop right now, but I or another member can name off some well known good brands if you need that.

 

[pbrstreetgang]

Yeah
I would definitely take a recommend
First was what came in it when I got it unknown now
Second was advance auto sourced
Third was a single wire because nothing else was working
And this last one was an ac delco that worked great and charged perfectly for three weeks and then crapped out

 

[squaredeal91]

Maybe you have a poor ground system?

 

[pbrstreetgang]

If I do I’m not sure where else to check
I’ve been through all the grounds

 

[SirRobyn0]

@pbrstreetgang AC Delco would have been on the top my list, new AC Delco first, reman second. I'd suggest that you pull the alternator and have it tested. It's certainly possible that there is nothing wrong with the truck, and you have just had a series of bad units. But given the number of alternators and that the last one was an ACDelco I would really want to make sure there is nothing wrong with the truck. Check over the grounds, it would be best if you took the grounds (at least the one that attaches to the alternator bracket) off and clean it up really well. Remember you need bare metal for good contact, rust and / or paint doesn't work. Reassemble with a little dielectric grease on the bare metal. Look over the connections to the alternator really good to. And look over the battery terminals.

I think that if there is a problem with the electrical system on the truck then the alternator(s) are not bad, the truck simply has an intermittent issue, or something you touch when replacing it, like a connector or terminal is bad and moving it around makes it work again. Take that alternator off and have it tested at the parts store. If it's bad explain how many alternators you have bought from them and demand a refund. The go to another parts store and get one so your starting with a clean slate and different supply chain, for example if all those alternators were at the same warehouse for autozone and something happened, they sat of the shelf for a decade, or they had a moisture issue and there's corrosion in the new alternator or IDK I'm just saying, try a different parts store if this one tests bad. If it tests good then you know there's an issue on the truck.

Brands we have good luck with on these trucks at the shop:
#1. ACDelco new
#2. ACDelco reman
#3. Denso (can be hard to get retail)
#4. Masterpro new (O'Rielly's)

Never A1 Cardone or Cardone. Never Napa branded reman'ed alternators as they are reman'd by Cardone. Some Napa new alternators are made by Richporter of Canada which is a really good company, but Napa also contracts with Cardone for new alternators so under the same part number one might have been made by richporter and the other by cardone. It's to hard to tell. It's unfortunate because Napa electrical products use to be top of the line. Now it's a crapp shoot steer clear.

That's what I can think of at the moment, hopefully it's helpful.

 

[Randy and Easton]

@pbrstreetgang we went through I think 3 remans from O’Reillyauto parts over I would say 2 1/2 years. Needed more amps for a slightly larger stereo and went with this one

https://www.summitracing.com/parts/pwm-7127

Randy and E

 

[pbrstreetgang]

Thank you for all of the help and suggestions

I have replaced batt pos and neg (ground) cables with new 2 gauge copper

All connection points get hit really well with electronics cleaner and steel brush until I see shiny. The alt mount for the battery ground got the same

I replaced the engine block ground to firewall with 2 gauge copper welding cable also

I cleaned every connection point on the alt and the starter and the corresponding cables and I cleaned the connections at the firewall junction block. All other grounds are wire brushed as I have found them.

One thing besides getting the alt tested and replaced with factory new is this

Where can I get a new starter to alt & junction block wire harness with correct fusible links and does anyone have a CLEAR diagram of how those wires route to their correct connections?

I have reviewed several diagrams and watched countless videos but they always leave critical info out and I can’t read a diagram on a technical level

I want to pull all of those and replace but they disappear into flex loom behind the block and I can’t make sense of what goes where.

Also, is it possible that the dash bulb is out for battery light and the brown wire is not doing its job?

 

[Ricko1966]

Thank you for all of the help and suggestions

I have replaced batt pos and neg (ground) cables with new 2 gauge copper

All connection points get hit really well with electronics cleaner and steel brush until I see shiny. The alt mount for the battery ground got the same

I replaced the engine block ground to firewall with 2 gauge copper welding cable also

I cleaned every connection point on the alt and the starter and the corresponding cables and I cleaned the connections at the firewall junction block. All other grounds are wire brushed as I have found them.

One thing besides getting the alt tested and replaced with factory new is this

Where can I get a new starter to alt & junction block wire harness with correct fusible links and does anyone have a CLEAR diagram of how those wires route to their correct connections?

I have reviewed several diagrams and watched countless videos but they always leave critical info out and I can’t read a diagram on a technical level

I want to pull all of those and replace but they disappear into flex loom behind the block and I can’t make sense of what goes where.

Also, is it possible that the dash bulb is out for battery light and the brown wire is not doing its job?

You said you are getting 12v on the exciter wire (dash bulb exciter circuit) in post 1 but asked about it on your last post,so you need to double check. The exciter is the dash bulb.Disconnect alternator charging wire and battery positive lead check continuity from alternator charging wire to battery lead, do a volt drop test on the same wire.pull the wiring plug at the alternator check continuity from term 2 to battery positive lead. If you have 12v on the exciter and the alternator is grounded,my money is on those 2 wires not 4 bad alternators in a row.
You can do a dirty wire around as a test. Run a wire from alt 12v post to battery positive post, run a jumper from term 2 to alternator charging post. Clip a test light to battery positive put the probe on term 1. Your light should light,start the truck your should go out. You can actually use 2/3rds of this circuit permanently with appropriate sized wires and a fusible link. Your term 2 jumper can be permanent,and battery lead can be permanent you still need a switched exciter on term 1. The test light represents the dash light,the jumper and the positive lead mimic the rest of the circuit.

 

[squaredeal91]

@pbrstreetgang AC Delco would have been on the top my list, new AC Delco first, reman second. I'd suggest that you pull the alternator and have it tested. It's certainly possible that there is nothing wrong with the truck, and you have just had a series of bad units. But given the number of alternators and that the last one was an ACDelco I would really want to make sure there is nothing wrong with the truck. Check over the grounds, it would be best if you took the grounds (at least the one that attaches to the alternator bracket) off and clean it up really well. Remember you need bare metal for good contact, rust and / or paint doesn't work. Reassemble with a little dielectric grease on the bare metal. Look over the connections to the alternator really good to. And look over the battery terminals.

I think that if there is a problem with the electrical system on the truck then the alternator(s) are not bad, the truck simply has an intermittent issue, or something you touch when replacing it, like a connector or terminal is bad and moving it around makes it work again. Take that alternator off and have it tested at the parts store. If it's bad explain how many alternators you have bought from them and demand a refund. The go to another parts store and get one so your starting with a clean slate and different supply chain, for example if all those alternators were at the same warehouse for autozone and something happened, they sat of the shelf for a decade, or they had a moisture issue and there's corrosion in the new alternator or IDK I'm just saying, try a different parts store if this one tests bad. If it tests good then you know there's an issue on the truck.

Brands we have good luck with on these trucks at the shop:
#1. ACDelco new
#2. ACDelco reman
#3. Denso (can be hard to get retail)
#4. Masterpro new (O'Rielly's)

Never A1 Cardone or Cardone. Never Napa branded reman'ed alternators as they are reman'd by Cardone. Some Napa new alternators are made by Richporter of Canada which is a really good company, but Napa also contracts with Cardone for new alternators so under the same part number one might have been made by richporter and the other by cardone. It's to hard to tell. It's unfortunate because Napa electrical products use to be top of the line. Now it's a crapp shoot steer clear.

That's what I can think of at the moment, hopefully it's helpful.

Good advice Rob. Im with you on the Stay away from napa starters and alternators waggon. Got bad ones for years. I got 3 bad starters for my square and gave up. Still using the newest broken one. Clicks allot before actually cranking.

 

[idahovette]

There is an older guy in Ontario Oregon(20 miles) that I go to for alternators and starters. He has been in business for almost 40 years and knows a LOT!!! Unfortunately, he is gonna retire and he can find NO ONE that wants to learn the trade and take over. Would be a great business to get into? His starters and alternators are top of the line and he doesn't have hardly any come backs. Usually it's operator error, if something doesn't work. Beats the hell out of NAPA, Autozone, or Oreillys........and reasonable!!!!!

 

[fast 99]

There is an older guy in Ontario Oregon(20 miles) that I go to for alternators and starters. He has been in business for almost 40 years and knows a LOT!!! Unfortunately, he is gonna retire and he can find NO ONE that wants to learn the trade and take over. Would be a great business to get into? His starters and alternators are top of the line and he doesn't have hardly any come backs. Usually it's operator error, if something doesn't work. Beats the hell out of NAPA, Autozone, or Oreillys........and reasonable!!!!!

I used 2 places in Spokane that were doing reliable electrical repair and testing, both have retired. Seems to be the state of that industry.

Not recommending NAPA but most of the stores here can test alternators. Having that many bad alternators in a row leads me to believe something else is going on. It's easy to get frustrated and overlook a simple problem. Been there done that.

 

[pbrstreetgang]

I did get 12 volts at alt plug - just wondered if the bulb receptacle could be shorting or something like that

Are Bosch alternators any count?
There is an auto electric guy one town over I may visit. He helped me back when I drove a M1009 Cucv with dual alternators on a 24v system