Engine fired up first time...but electrical help needed

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Rat Patrol

Rat Patrol

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...ran very smoothly.....but then the alt charge wire started to melt!!':banghead:

The alternator went into full charge........and it was lucky I was running a shunt wire or my ammeter would have been toast.

I can only assume the internal regulator was't working....and I think I may have stuffed up the wiring.

...can someone detail the correct charge circuit wiring for a 150 amp INTERNAL REGULATOR alternator?

My alt is a Jeep SRT...With a twin pin socket and one post that the main charge wire attaches to.

Dont care if I run the ammeter or not.....but I need to know where to wire the twin post socket to.
 
Are you using a factory computer?? If so, the computer controls the voltage the alt. puts out. Also, I dont think it's a good idea to run an ammeter...most people will bypass it and use a volt meter instead.
 
Are you absolutely positively sure that this is an integral regulator?

My understanding is that most of the modern Mopar stuff has the regulator IN the computer, NOT in the regulator.

How do you have the alternator wired, and can you post a photo of the alternator?

BE CAREFUL. If this thing is "full fielding" or full output, the charge voltage can go very high, and just might kill some stuff --like your EFI computer.
 
Ok...Ive mislead you guys...heres the drum....

The alternator is a factory 6.1 ...I hadn't realised they had no regulator inside.

I have no efi, no computer, just a spark module...Im running a carb.

When we started up...I had wired it to the external reg (solid state)

The ammeter went hard over and the charge wires started to cook.

Id like to know what the recommended wire up is...and Ill check it against what Ive done and report back

This is easier than me trying to explain what Ive done. :)
.
 
So far as I know, all of these are just like the 70/ later Mopar alternator, that is, two field connections. So you should be able to use a EITHER a replacement 69/ earlier regulator OR a 70/ later regulator

69/ earlier, ground either field terminal, and run the one left to the screw terminal on the regulator

Make sure the regulator is grounded

Run the "push on" connector of the regulator to switched 12V, IE "ignition run." CHECK this to make sure it is "same as battery," IE no voltage drop

69/ earlier regulator:

a64736b139848eabbf7f4b_m.JPG



===================================================================
===================================================================

70/ later: See diagram below:

Run either field terminal to switched 12v IE "igntition run"

Run the remaining field terminal to the F terminal on the regulator as in the diagram

Make sure the regulator is grounded

Run the "I" (IGN) terminal to to switched 12V or "ignition run". Once again, make sure that this terminal is "same as battery."

Easy way to do that is turn key to run, engine not running. Stab one probe of your meter directly onto the battery POS terminal, and the other to the regulator "I" terminal or as close as you can get. You want to see a very low voltage, the LESS the better, and not over .2v (two tenths of one volt.

This IGN terminal IS not only the power supply for the regulator, but also the SENSING terminal. What this means is, that voltage drop TO that IGN terminal will "make the regulator think" that the battery is LOW, and will ramp up charge voltage.

ALSO, I'm wondering if there might be something else mis--wired. MAKE SURE the battery (output) connection of the alternator is actually hooked to battery positive--- even if an alternator is charging full output, it should not burn up wiring

70 / later diagram:

Dual_Field_Alternator_Wiring.jpg
 
Thx for taking the time to provide such a comprehensive run down,

I am using the later external reg.

Believe it or not, that diagram is how I "thought" I had it wired....but I may have run the wire to the 12V switched incorrectly.

I wont have access to the car till Monday...but I intend on re-checking everything including the wiring to the fuse box and ammeter - then Ill check how Ive run the two field wires......and the reg earth.
 
A couple more thoughts. Not being to sure of what exactly you burned up, make sure that both field connectors of the alternator (with everything disconnected) DO NOT show any continuity to ground. It is possible on some alternators to experience improper assembly or a broken brush holder which grounds one brush holder. This may not turn out well!!
 
Ok..Ill check that as well.....it'd be just my luck!

Basically I ran an extra wire from the charge post to the battery +ve....to halve the current draw through the ammeter.

We call it a shunt wire.

Thats why I have to check the original charge wire....it may have gone out as well behind the dash
 
Check also the connector of voltage regulator,specially if that is 40+ years old. The brass/copper plugs can loose the tension and the wires can be broken inside the rubber, making the charging voltage raising too much.

I made also extra ground cable from regulator to engine via car body. And two good grounds from engine to the body.
 
Jousi said:
Check also the connector of voltage regulator,specially if that is 40+ years old. The brass/copper plugs can loose the tension and the wires can be broken inside the rubber, making the charging voltage raising too much.

I made also extra ground cable from regulator to engine via car body. And two good grounds from engine to the body.
Click to expand...

Im going to double check the reg Im using
 
Electrical problems are always found in the last place you look.
If there was 5 or 10 minutes run time before the melt down you'll need to check the wiring to the starter. Wires melted to a header, a short at or inside the starter/silinoid.
There are threads here where the entire car is being rewired when the actual problem hasn't been found yet.
If "entire car" doesn't include jack it up and check the starter and its wiring, the fault may still exist. Good luck to all.
 
Changed the solid state reg and checked the connections.

Thought I had the problem licked because the ammeter was showing only a slight charge......but the shunt wire does reduce the amount of measured current thru the ammeter so thats something?

Put a meter on the alt but its still pumping out 18 volts at idle.

Then something blew under the dash so we shut it down.

Going to check all grounds and under dash wiring tomorrow
 
Just use new "jump" wires and some common wire terminals and wire the alternator like the Joe Dokes pic, be sure regulator is on good ground and finger-thick cable :) directly to battery plus from alt output.
+12V to other field and regulator you can take also directly from the battery for now just for this test. If it still charge more that 14,4V problem is in the regulator or alternator. This way you can count out car wirings, also by pass the ammeter, it will melt anyway at some point.
If charging is now good, then rewire the permanent loom, and search good and stable switched 12V from fuse box etc. This need to be strong also when engine is running, maybe the ammeter is now mixing this voltage and that why the problem occurs.

Simple system this mopar charging, problems coming when there are old wires and new 130+A alternators.
 
Rat Patrol said:
Changed the solid state reg and checked the connections.

Thought I had the problem licked because the ammeter was showing only a slight charge......but the shunt wire does reduce the amount of measured current thru the ammeter so thats something?

Put a meter on the alt but its still pumping out 18 volts at idle.

Then something blew under the dash so we shut it down.

Going to check all grounds and under dash wiring tomorrow
Click to expand...

YIKES

There are only so many problems that can cause this

1--Battery is not truly connected to the alternator output

2--Bad regulator, bad regulator ground

3--If one end of alternator field (broken terminal insulator, etc) is grounded, and ignition feed is hooked to other field terminal, then alternator will "full field" and produce full output

4--Low ignition feed to regulator IGN terminal will cause overvoltage, but not normally to this extent

==========================================================

I realize that now some damage has been done, this might get complicated, but

It is important to "watch" throttle settings and monitor battery voltage along with alternator output stud voltage to be sure both are "close to each other."

Determine that the field/ regulator wiring "has control" by disconnecting the regulator connector. Output of alternator should drop, IE battery should drop, eventually down to 12.6 or lower

If this seems OK, briefly test field wiring by first

A. With regulator plug disconnected, ground the green field wire briefly. At slightly fast idle, this should cause some output, IE battery voltage should go up from 12.6

(The above is the wire from one alternator field terminal to the regulator field)

to 14 OR MORE

B. Remove the field wire which goes to switched ignition, and ground that alternator field terminal. At the regulator connector, jumper the two terminals in the connector together. This should cause the same result as "A" above.

If these two tests are OK, the wiring "should have" control of the alternator.

C. Double check that the FIELD wire from the alternator to the regulator is actually hooked to the OUTER terminal in the regulator connector. With alternator field unhooked, regulator connector unhooked, and key off, this is a simple continuity check.

D. If none of the above shows any problems, check voltage at the field terminal coming from switched ignition, key "in run" but engine not running. This voltage should be within .2V of "same as battery."

E. DOUBLE check that regulator is actually grounded, IE scrape clean, use star washers, etc.

You have already tried another regulator?
 
1 - The reg was changed prior to my previous post...I had wired it incorrectly so thats part of the reason the Alt went onto overcharge.

2 -After fixing the wiring and changing the reg, I attached an earth wire to the regulator mounting screw to mmake sure it was grounded properly

3 - I performed the suggested check to the alt field posts to ma,ke sure they were not grounding.....the resistance showed infinity so no issue there.

I SUSPECT a dodgy battery terminal connection, or a bad battery earth. ( My battery is in the trunk connected by HD welding wire to the start relay post.

Trouble is, we now have collateral damage to fix....so under dash will require inspection before any further testing can be done.

Thanks for the tips everyone on testing.......Ill be sure to let you know what we find.
 
SUCCESS!......The problem was a combination of a bad earth at the Nve battery terminal, a poor earth between motor and chassis......and the battery cut out switch has been removed.

I pick the car up tonight! :)
 
Damn!!! That's a good way to kill some very expensive electronics Glad you made headway
 
Aren't u Happy you didn't have a computer to blow up Rat !!!!!!! I had a starter alternator shop wire in a internal regulator to mine to make it a true one-wire alternator--Used the stock alternator for my 5.7--Steve
 
Yup...very glad all it cooked was the shunt wire.

Everything has been relayed in now.

Before I go racing again Ill make sure my cut out switch is wired back in and not creating a bad earth.....and I want to fit another switch that cuts the fuel pump in the event of a roll over.
 
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