Grounds and electrical stuff.

[ofelas]

11 minutes ago, Mopar1973Man said:

1st Gen no listing of any fuse or fusible link... Dodge Factory Service Manual.

 

2nd Gen... Clearly shows the fuse...

 

As for 3rd gen and up I'll have to EAT MY WORDS... 

 

There is a fusible link but it in the loom somewhere. 

 

 

 

LOL. You'll be eating your words again.

 

First off, that's not a 1st Gen Cummins FSM. It's a generic ChryCo diagnosis procedure is all, which doesn't show as much detail as a proper wiring diagram.

 

I will give you A for effort, considering you likely haven't worked on many vehicles other than your own.

 

Here is the fusible link on a first gen Cummins below. It's the 6ga BK wire in the middle of the page, which goes from the passenger fender shield along the firewall and then on the drivers side fender shield; the Hypalon is the fusible link, a few inches away from the BATT(+ve) post.

 

 

 

 

 

4 minutes ago, rotohead said:

 

So what do you suggest to avoid this potential fire hazard if I wanted to make it right?

 

If it's the existing factory 136amp alternator, keep the factory 140amp PDC fuse.

[rotohead]

3 hours ago, rotohead said:

 

So what do you suggest to avoid this potential fire hazard if I wanted to make it right?

 

So if you don't mind me asking, what in your system would make it output up to 2200amps? Just curious and what fuse do you use to cover the fire hazard at that output? I appreciate the information. I'm contemplating my next alt replacement to a 200 amp output model.

[ofelas]

A battery with a 5 second CA rating of 2250amps.

 

No fuse will protect a battery shorting to ground!  The fuse is only to allow the alternator to supply charge current to the battery without blowing!

 

When in doubt, 10% above max alternator amperage under full load is very safe.

 

I use a 200amp charge circuit fuse as my alternator, though rated at 160amps, has been tested by me to supply 180-ish amps at full load.

 

Beware of the commonly available 200amp alternator ratings - they use smaller pulleys/misleading alternator rpm ratings to entice buyers with "200 amps".

 

Ask them "at what alternator rpm does this unit produce 200amps under load".

 

Most alternators trade idle amps for amp output at unrealistic alternator rpms.

 

Remember, we are talking about low revving inline 6 diesels here.

 

The alternator rpm at idle/higher rpm needs to be matched to pulley ratio & estimated engine idle/speed rpm for efficient charging.

 

Look for a 12 diode + 6 phase stator unit & go from there. They are far more efficient at low/idle rpm.

 

I posted pics & part #s of the setup I use on every Cummins I own/work on a couple days back.

[Mopar1973Man]

I humbly bow out... 

[rotohead]

16 minutes ago, ofelas said:

A battery with a 5 second CA rating of 2250amps.

 

No fuse will protect a battery shorting to ground!  The fuse is only to allow the alternator to supply charge current to the battery without blowing!

 

When in doubt, 10% above max alternator amperage under full load is very safe.

 

I use a 200amp charge circuit fuse as my alternator, though rated at 160amps, has been tested by me to supply 180-ish amps at full load.

 

Beware of the commonly available 200amp alternator ratings - they use smaller pulleys/misleading alternator rpm ratings to entice buyers with "200 amps".

 

Ask them "at what alternator rpm does this unit produce 200amps under load".

 

Most alternators trade idle amps for amp output at unrealistic alternator rpms.

 

Remember, we are talking about low revving inline 6 diesels here.

 

The alternator rpm at idle/higher rpm needs to be matched to pulley ratio & estimated engine idle/speed rpm for efficient charging.

 

Look for a 12 diode + 6 phase stator unit & go from there. They are far more efficient at low/idle rpm.

 

I posted pics & part #s of the setup I use on every Cummins I own/work on a couple days back.

 

Thank you very much. I truly appreciate the info and advice.

[JAG1]

On 11/10/2018 at 3:05 PM, Mopar1973Man said:

I humbly bow out... 

No worries Mike... you owe us all a round of beer 

Edited November 13, 2018 by JAG1

[ofelas]

12 minutes ago, Mopar1973Man said:

I humbly bow out... 

 

Please don't; your experimentation is part of what makes this a great site; I don't want to rub anyone the wrong way  

 

8 minutes ago, rotohead said:

 

Thank you very much. I truly appreciate the info and advice.

 

Anytime! I'd start by calling Nations Alternator, or find a junkyard split case 160amp unit. The split cases indicate a 12 diode 6-phase stator unit, whether 136amp or 160amp. You'll have to swap your 8 groove pulley on to the above mentioned gasser 6/7 groove alternator.

 

Rest assured that a factory second gen 60mm groove diameter pulley puts out enough amperage at idle & higher rpm to keep the battery with grids cycling happy, even for multiple short tripping. If you have the 2-pin field plug on your factory alternator, it swaps right in. If you have the earlier plastic box field/batt/ground ring terminal connectors, you'll need to cut & splice in a single new 2 wire field circuit socket, a 5 minute job. Move the ground cable from the back of the earlier black plastic box alternators to the front alternator bracket bolt - make sure the contact surfaces are unpainted, as these systems ground via the alternator case to support bracket bolt.

 

The first gen 120amp alternators had 65mm alt pulleys...going to the 60mm pulley on the second gens is what likely resulted in their similarly rated diode amperage to publish the second gen alternator being rated at 136 amps ;-)

11 minutes ago, JAG1 said:

No worries Mike... you own us all a round of beer 

 

I've been known to change head gaskets/injection pumps/crank seals free for those in need, and even supply the beer.

 

I'm up for a few beers anytime 

[rotohead]

16 minutes ago, ofelas said:

 

Please don't; your experimentation is part of what makes this a great site; I don't want to rub anyone the wrong way  

....

Yes, don't go away. I appreciate all ya all's info and help.

When ofelas talked about fire hazard that got my attention. When I was in Army flight school in 1969 at Ft Walters TX while riding from the flight line in those military school buses the one I was in overturned in a ditch, started on fire and with 30 plus soldiers trying to exit with only limited exits, I was never so scared in my life. Even a tour of duty as a Huey pilot I was never as scared as I was in that bus. Dying in a fire has to be the worst way to go, so when the subject of vehicle fires comes up I'm paying attention. There just had to be a reason a fuse is in that PDC circuit. I'm no genius when it comes to electricals and know just enough mechanicals to get me in trouble. When someone like ofelas is talking I'm listening. Thanks again, Chuck Krause

 

[ofelas]

I'm a bit younger than you are, but I've fast roped down plenty a 160th whirlybird; props to you helo boys for flying in a bucket of bolts.

 

Personally, I think a fixed wing is just plain wrong, unless we're talking about the GE rotary pest control platform.

 

On the C series fixed wings, a quick exit at 30k feet got me quicker to solid ground ;-)

 

And yes, I was stupid enough to jump out of 141's too.

 

And here we both are worried about underhood fires 

Edited November 11, 2018 by ofelas

[JAG1]

So for safety sake.... installing a bolt down fuse mount and run the charge wire thru the correct size fuse? Right?

 

This way running the B+ to the passenger battery is still possible and is important because your giving the batteries a chance to filter out ac ripple before running thru PDC and everything else connected.

 

Is that right?

 

[rotohead]

18 hours ago, JAG1 said:

So for safety sake.... installing a bolt down fuse mount and run the charge wire thru the correct size fuse? Right?

 

This way running the B+ to the passenger battery is still possible and is important because your giving the batteries a chance to filter out ac ripple before running thru PDC and everything else connected.

 

Is that right?

 

 

That is the way I understand it. Excluding a factory fuse when rerouting the charge wire didn't seem to be a good move in my eyes. I'll gladly spend a few bucks to include a proper fuse on the passenger side battery. I'm going to use the PDC wire to power my FASS lift pump.

[dripley]

12 minutes ago, rotohead said:

I'm going to use the PDC wire to power my FASS lift pump.

Moved my AD power there when I did the ground mod.

[rotohead]

2 hours ago, dripley said:

Moved my AD power there when I did the ground mod.

 

AD power? Curious. I guess any constant hot power source could be used I would think.

[dripley]

7 minutes ago, rotohead said:

 

AD power? Curious. I guess any constant hot power source could be used I would think.

Air Dog lift pump. I connected the power to the PDC terminal. Thought thats what you meant above with your FASS.

[rotohead]

7 minutes ago, dripley said:

Air Dog lift pump. I connected the power to the PDC terminal. Thought thats what you meant above with your FASS.

 

yep samo.

[JAG1]

Thanks to Ofela for bringing this up. Pray for W-T that he is okay that his home is still there as over half of his town of Paradise Calif. is burnt to the ground. It really sad.

[rambo]

On 11/4/2018 at 1:01 AM, Exalted85 said:

It'll melt solder..really confused here. Could it just be dissipating heat too fast? So odd. I'll have to look into a pencil torch tomorrow..I have one more day :/

It's definitely just not conducting heat for some reason. I held it on there for a while, then touched it..nothing. I hate electricity. Need fire.

 

Just for shits..I held it under a candle..it definitely got hot..but did chill pretty quickly. 

If you are using a new soldering iron you have to tin the tip so it will conduct the heat more quickly. its been a while so ck it on u-tube, but heat the iron, place tip of hot iron in flux about 3 seconds a couple of time remove tip from flux and wipe flux and any dirt off tip  with a very damp sponge or paper towel. Reheat the tip and melt solder all around entire tip, wipe tip again with sponge and you will see solder

is bonded to tip and now is very conductive with heat.

Edited November 12, 2018 by rambo

[Dieselfuture]

On 11/10/2018 at 5:29 PM, ofelas said:

I've been known to change head gaskets/injection pumps/crank seals free for those in need, and even supply the beer.

Not easy to come by good people, they're out there. I used to be one of them, but not much time anymore 

[ofelas]

On 11/10/2018 at 1:55 PM, Mopar1973Man said:

 

 

 

 

So now search back on the internet and you find no such thing has ever happened. The diode will burn out like a fuse and that the end of it. The circuit is now open.

 

 

Just remembered this picture, forgot to post about it.

 

This usually happens because the stator and rotor were upgraded without upgrading the rectifier rating.

 

When positive diodes are burned out, best case scenario is a fully open connection, and the worst case scenario is a catastrophic short/under hood fire.

 

I don't have a diagram of that rectifier on hand, but it looks like burned out negative diodes, which means there was probably a bad ground connection between the alt and the battery - this would result in a drained battery.

 

 

[rotohead]

1 hour ago, ofelas said:

 

Just remembered this picture, forgot to post about it.

 

This usually happens because the stator and rotor were upgraded without upgrading the rectifier rating.

 

When positive diodes are burned out, best case scenario is a fully open connection, and the worst case scenario is a catastrophic short/under hood fire.

 

I don't have a diagram of that rectifier on hand, but it looks like burned out negative diodes, which means there was probably a bad ground connection between the alt and the battery - this would result in a drained battery.

 

 

 

I read what you post, then I research and educate myself via the internet on the information. I'm not sure I'm any more educated (actually I know I'm not) but I do feel more capable of setting up my truck to be more safe and correct. Please keep it coming if there is anything else you just remembered.