Electric Fan Wiring Advise

[pnora]

If you look at the diagrams for a 1969 Charger there is no HD fuse in the wiring. The only fused link is at the bulkhead connector which is on the starter relay circuit. I don't see any fused links shown in the schematics. However we all know there are at least 2 at the bulkhead connector. Also if you think about it. Why do ammeters cause fires if they are fused. Would it not pop the fuse before it burns down a dash? Oh wait there is no fuse in the charging system of a 69 charger.

Like I said the main fuse link. One gone all is done. For the most part the link is adequate for the loads it was designed to run under. The system was already inherently weak and failure prone with age. Add more loads off the alternator stud and you can earn that magic kiss of death black smoke.

 

[Canadian1968]

You have a fuse link. When you overload that the whole system is most likely dead. There are some variants depending on year. You take a older car and load off the alternator stud you are asking for problems. Worse when the alternator dies and all loads are on that old wiring. Failures will be in wires overheating, ammeter looking like a toaster element along with the bulkhead connections. If you have a bypass done and have a large 6 gauge wire or bigger to the alternator it will help. Just look at what has been done to cars for the last 25 plus years. They run a PDC with all loads including alternators of of fuses. Go out there and find cars, trucks, equipment that run off the alternator stud. Good luck with that search. If that was the way to do it the factories would have done it. Like I said no one will do a hack job like that on anything I own.

I don't care what cars today have. Does our 60s car have the same electronics as a 2019 dodge pick up? NO so don't compare .
So as you stated the only fuse , is the fuseable link on the engine side of bulkhead.

You fry your fuseable link, the system is not dead, until you turn off your car. Your ALTERNATOR will keep the car running. Your alternator DIES, yup your car will go threw a slow painful death as the batttery supplies until its drained, it won't cook everything. Remember that fuseable link???? Load becomes to much , guess who pops?

So with running everything off the battery post, Your power is coming from the "battery" But your battery is simply stored energy, so it only last so long. You NEED the alternator to keep that battery charged. In the FACTORY setup , ALL that current, is now going ALL the way threw the car threw that bulkhead ( which is a known WEAK link ) and trying keep that battery topped up. You now put that LOAD on the alternator side , the LOAD no longer has to pass threw every connection to make it back to the battery. It is fed right off the alternator to the load. Lets not forget of course this NEW load has an inline fuse.

You run a bunch of junk off your battery, its not going to regenerate by itself. It needs the alternator. Your line of thinking is to have the battery constantly be in a state of discharge, and have the alternator keep it up. Which means constantly sending current threw every weak link in the system?

THE FACTORY system is not perfect, its actually horrible. The split point is honestly the famous AMP gauge. Its crude and rude, but honestly it tell you the entire story of the electrical system, IF you undersand it.

You do you. Will your way work, yes it will. Will my way work , yes it will. The important thing to know is how THIS system works.

Ohhhh and can you show me where the ABS, BCM, ECM, Blind spot detection , DC to AC inverter, adapative cruise control, DRL and air bags are??? I can't find them I.m just a hack,

 

[pnora]

I don't care what cars today have. Does our 60s car have the same electronics as a 2019 dodge pick up? NO so don't compare .
So as you stated the only fuse , is the fuseable link on the engine side of bulkhead.

You fry your fuseable link, the system is not dead, until you turn off your car. Your ALTERNATOR will keep the car running. Your alternator DIES, yup your car will go threw a slow painful death as the batttery supplies until its drained, it won't cook everything. Remember that fuseable link???? Load becomes to much , guess who pops?

So with running everything off the battery post, Your power is coming from the "battery" But your battery is simply stored energy, so it only last so long. You NEED the alternator to keep that battery charged. In the FACTORY setup , ALL that current, is now going ALL the way threw the car threw that bulkhead ( which is a known WEAK link ) and trying keep that battery topped up. You now put that LOAD on the alternator side , the LOAD no longer has to pass threw every connection to make it back to the battery. It is fed right off the alternator to the load. Lets not forget of course this NEW load has an inline fuse.

You run a bunch of junk off your battery, its not going to regenerate by itself. It needs the alternator. Your line of thinking is to have the battery constantly be in a state of discharge, and have the alternator keep it up. Which means constantly sending current threw every weak link in the system?

THE FACTORY system is not perfect, its actually horrible. The split point is honestly the famous AMP gauge. Its crude and rude, but honestly it tell you the entire story of the electrical system, IF you undersand it.

You do you. Will your way work, yes it will. Will my way work , yes it will. The important thing to know is how THIS system works.

Ohhhh and can you show me where the ABS, BCM, ECM, Blind spot detection , DC to AC inverter, adapative cruise control, DRL and air bags are??? I can't find them I.m just

I enjoy helping people. I also do not like to pass on dis-information. I suggest to get some electrical schooling and not going off what you think you know. I can pick apart every sentence you just posted but I have better things to do. May the black magic smoke be with you.

 

[Crackedback]

which device runs the car?

What is the cars voltage in static state, engine off?
Same reading with engine running at a reasonable off idle RPM?

Hook accessories up, especially high amp draws, at the battery on a OEM charging system mopar and watch the fun as the harness melts itself.

Unfortunatley there is no "perfect" spot to hook up anything on an OEM muscle car mopar.


OP, run the fan using a relay. Take as much load off the expensive switch and OEM harness as you can.

 

[Canadian1968]

Truth be told, when I installed my fans I hooked it up EXACTLY as you said, off the Battery. I had nothing but problems, the car would struggle at idle when the fans come on, only when the fans came on. I did voltage checks, and tested connections, had my alternator tested, did this and that. Came on here for help, it wasn't until someone explained to me how the factory system on 68 Charger works, did I switch over to Alternator stud for high amp load such as fans ( my fans actually only draw a combined 20 amps ) . Since the switch, not a single problem they work flawless , amp gauge is happy and so is my battery.

A friend with 67 GTX wired up a high amp Fan for his car, along with running a FI-tech system had it all run off his battery, The positive post looked like a rats nest. The car was over heating, hence the chase for the an electric fan fix. The problem was still there and the car would never stop after he shut it off, with out a boost.
In his case, he had multiple problems , one being that the alternator was an original unit, not sized correctly for the new loads he was adding. So all these new loads , running off the battery were to much, the alternatior couldn't keep up with the loads AND charging the battery. It kept the car running, but couldn't charge the battery as well. Guess whos bulkhead connection was starting to melt? NOW he was super lucky that he did't not burn up his car. That Alternator was running MAXed out to try and keep and push ALL that current to the battery.

 

[pnora]

Hook accessories up, especially high amp draws, at the battery on a OEM charging system mopar and watch the fun as the harness melts itself. That works both ways. Have the load off the stud without the engine running or if the engine stalls out. That 12 gauge alternator wire along with everything else going back to the battery will begin to be very unhappy and start to roast.

 

[Nacho-RT74]

Once again, and without a direct quote, because would need to quote several replies.
ALT IS NOT FUSED ANYWHERE on cars built before 1975 or so when Mopar began to remove the full load amps from all the body lines and replace with shunted charging systems ( maybe some C bodies did since they began to get shunted wiring on 70/71 I think ) ... not even the ign system is fused!!!!

In case of a short the only source to keep sourcing the short will be the batt, because is the only source able to keep sourcing without anything to stop it untill its load reserve is death, hence why the fuse link is ONLY on batt side of the ammeter. If you disconect the batt with engine running ANY small short will be able to stall the engine ( ign system which also keeps the reg/alt alive will get its power sucked out) so the power source will dye with it, and won't get any electrical source able to keep alive the short. Just the batt is able.

 

[Nacho-RT74]

and this is a diagram I made to wire by ourself the fan setup with a temp switch AND linked to the A/C compressor for a cooler setup when A/C is on... double fan ilustrated with double temp rate switch, but single can be the same.

 

[Crackedback]

But that is where the thought process of, in which state is the engine usually in when the item I'm powering is in operation should be addressed.

Fans are both, which makes it difficult. Stereos can be the same.
Headlights, 99% of the time, engine running.
AC compressor, engine on
Fuel pumps,

IMO, Best thing is to get rid of the OEM charging route.

 

[pnora]

Once again, and without a direct quote, because would need to quote several replies.
ALT IS NOT FUSED ANYWHERE on cars built before 1975 or so when Mopar began to remove the full load amps from all the body lines and replace with shunted charging systems ( maybe some C bodies did since they began to get shunted wiring on 70/71 I think ) ... not even the ign system is fused!!!!

In case of a short the only source to keep sourcing the short will be the batt, because is the only source able to keep sourcing without anything to stop it untill its load reserve is death, hence why the fuse link is ONLY on batt side of the ammeter. If you disconect the batt with engine running ANY small short will be able to stall the engine ( ign system which also keeps the reg/alt alive will get its power sucked out) so the power source will dye with it, and won't get any electrical source able to keep alive the short. Just the batt is able.

Get a 69 FSM [example] follow the alternator wire. it goes through the bulkhead, ammeter, and to the bulkhead terminal R. On the engine side off terminal R is a fuse link. To prove the point ground the alternator wire at the alternator and that fuse link will burn. So do not say it is not fused.

 

[pnora]

But that is where the thought process of, in which state is the engine usually in when the item I'm powering is in operation should be addressed.

Fans are both, which makes it difficult. Stereos can be the same.
Headlights, 99% of the time, engine running.
AC compressor, engine on
Fuel pumps,

IMO, Best thing is to get rid of the OEM charging route.

Thats what I do. Alternator wiring heavy gauge [I used a painless kits] with a fuse connection to a central point and direct to the battery. All other loads are off the central point.

 

[Crackedback]

Thats what I do. Alternator wiring heavy gauge [I used a painless kits] with a fuse connection to a central point and direct to the battery. All other loads are off the central point.

The ammeter lovers will be in to tell you that you are incompetent and know nothing in a few minutes.

I don't like the mad approach, however, IMO, the bulkhead should be taxed to provide power for loads requested by the cabin. The packard terminals in reality were not dsesigned to carry anything near the max loads of even a stock mopar alternator. That is a design problem, even if the normal anticipated operating loads were never close to max. Then they did the fleet bypass as a crutch/bandaid.

 

[pnora]

The ammeter lovers will be in to tell you that you are incompetent and know nothing in a few minutes.

I don't like the mad approach, however, IMO, the bulkhead should be taxed to provide power for loads requested by the cabin. The packard terminals in reality were not dsesigned to carry anything near the max loads of even a stock mopar alternator. That is a design problem, even if the normal anticipated operating loads were never close to max.

I did forget to say I always convert to a voltmeter. Being in a Mopar dealership since 1972 I am well versed in bulkhead, ammeter, and wiring carnage.

 

[Canadian1968]

WTF.

The only way this works is 1. The car has to be hot to where the thermo switch is closed first. 2. The car dies and you just sit there and do nothing? The relay needs IGN 12V . as soon as you turn off the key the relay open and fans are off.

Its not like the fans just run whenever by themselves...... unless you had them hooked directly to a battery with a switch , and you turned then on just to see how fast you can kill your battery?

 

[Nacho-RT74]

Thats what I do. Alternator wiring heavy gauge [I used a painless kits] with a fuse connection to a central point and direct to the battery. All other loads are off the central point.

That fuse link is for THE BATT not for the alt.

Try this... disconect the batt with engine running and short out any wire of the ign system. Or even short out the alt stud with a jumper wire ( 14 or 16 gauge wire will be enough ) straight to any chassis point around, to keep safe the car wiring... and check if the fuse link blows.... or if the engine stalls ?

Don't worry, nothing will happen aside the jumper wire heat and some sparks around from same wire... the engine will stall... trust on this.

BTDT...

 

[Canadian1968]

That fuse link is for THE BATT not for the alt.

Try this... disconect the batt with engine running and short out any wire of the ign system. Or even short out the alt stud with a jumper wire ( 14 or 16 gauge wire will be enough ) straight to any chassis point around, to keep safe the car wiring... and check if the fuse link blows.... or if the engine stalls ?

Don't worry, nothing will happen aside the jumper wire heat and some sparks around from same wire... the engine will stall... trust on this.

BTDT...

I think the ego is to big to admit his faults.

Multiple people have agreed with my original statement. With an OEM style system u want a high amp load on alternator side of the system . Hopefully the original poster has followed his own thread !

 

[pnora]

[[[[[[That fuse link is for THE BATT not for the alt.]]]]]]] Bull crap. The link is there to disconnect the power in event of a short to ground or excessive load. A fuse link is there to protect the rest of the car period. The design of the system is if anything goes to ground it will hopefully burn before any other damage is done. So any wiring that is not fused goes to ground the fuse link blows.

 

[Nacho-RT74]

If you say I'm wrong just have one thing to do... TRY IT

what's the fear about ? LOL.
the only way to blow the fuse on the stage I mentioned ( with batt disconected ), is if you make the short on the wire running to batt post... and mostly sure EVEN ON THAT WAY, the engine will stall before blown the fuse. Alt ( at iddle ), and even more if stock is not able to keep the engine alive with any small short and without a batt. Any small short around will suck up the load for the ign system from low stock ( or even mid output rate ) rated alts.

The stock fuse link is able to handle up to 50 or 60 amps for a couple of seconds maybe ? ( I don't have the rates chart handy at this moment ), and stock alts barelly reachs 20 (maybe) amps at iddle and if demanded, maybe 40 ?. Ignition system load will be sucked out before that.

Sure some red X will float around soon.

 

[pnora]

If you say I'm wrong just have one thing to do... TRY IT

what's the fear about ? LOL.
the only way to blow the fuse on the stage I mentioned ( with batt disconected ), is if you make the short on the wire running to batt post... and mostly sure EVEN ON THAT WAY, the engine will stall before blown the fuse. Alt ( at iddle ), and even more if stock is not able to keep the engine alive with any small short and without a batt. Any small short around will suck up the load for the ign system from low stock ( or even mid output rate ) rated alts.

The stock fuse link is able to handle up to 50 or 60 amps for a couple of seconds maybe ? ( I don't have the rates chart handy at this moment ), and stock alts barelly reachs 20-25 amps at iddle.

Why do I want to disconnect the battery? This has nothing to do about what I have said. I know exactly how an alternator and battery work. We are talking about a properly running system. Tell me this what would happen if the alternator shorted internally to ground.

 

[Nacho-RT74]

Tell me this what would happen if the alternator shorted internally to ground.

The batt will source the short, and on that moment the fuse will blow... but just because THE BATT is sourcing the short.

Now what could happen on same stage without the batt ?

Answer: the engine will stall and the fuse link will do NOTHING, because the fuse link is out of the game on that moment without a batt presence