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-   -   How to put in an external voltage regulator? (http://www.jeepforum.com/forum/f12/how-put-external-voltage-regulator-1214476/)

smgbsdc 05-15-2011 10:56 AM

How to put in an external voltage regulator?
 
Swapped ecu ... Now it starts but my battery dies... Someone said put in external regulator... How do u do that?

UltimatE 05-15-2011 11:26 AM

If you charge the battery, and start the Jeep, what is the voltage while running? After charging the battery, what is the resting voltage of said battery?

JWELK 05-15-2011 04:45 PM

There are 4 terminals on the back of the alternator, two are in a plug. You have a heavy red wire that goes to the battery, and heavy black ground.
The two wires in the plug are what we are concerned with. Do you have a voltmeter and are you comfortable using it? Starting at the heavy red battery terminal going CCW the 2nd wire SHOULD be the ground, the third (1 of the plug wires) goes to the ignition switch, the 4th (the other plug wire) goes to the ECM, This is the charging sense wire. Measure the voltage between the Heavy red lead and this lead. (Red meter lead to heavy red battery lead and black lead to the 4th wire. You should see a positive voltage, If the voltage is 0, place the red meter lead on the 4th wire and the black meter lead to ground, you should read battery voltage (14 volts or so). If you see 14 volts, the ECM is probably bad. If you want to test it let me know and I'll give you a quick easy test.
Regards,

Jim W.

smgbsdc 05-15-2011 06:57 PM

Thanks man.... I will have to borrow a volt meter tomorrow

smgbsdc 05-15-2011 06:59 PM

What's the quick easy test for the ECM? I though the manual one would work in an auto... Could have been bad info

JWELK 05-16-2011 04:53 PM

Don't know how to test the ECM. But.... on my '95 the two plug wires. The 3rd wire goes through the ignition switch to the battery, the 4th wire goes to the ECM. These two wires go to the the field in the alternator. The rate of charge is determined by the current flow through the field. As wire 3 goes to the ignition switch, it is fixed at the voltage of the battery minus any losses in the wires. If there is no current flow in the field AND the field wire is intact the voltage on the 4th wire will be equal to battery voltage. If this voltage is less than "X" a circuit will turn on and allow current to flow through the field. This will allow the alternator to produce current and charge the battery.
To test you must make a circuit. A brake lamp, (combo brake and tail is preferable) socket, clip-clip leads will be sufficient. Connect 1 clip-clip lead to the lamp socket. Now for the good stuff. Take the red meter lead and connect it to the the + battery, black to -. Now go 6" or from the plug and cut wire 4 leaving wire 3 intact. Strip 1/2" from the "alternator" side of the wire and connect either clip lead. Start the car, and check the battery voltage. Take the unconnected socket lead and attach it to a good ground. The lamp should light and the Voltmeter should increase indicating the alternator is charging.
If the lamp does NOT light...check for voltage on wire 3, then check for voltage on wire 4. If there is voltage on 3 and none on 4 the alternator is bad, (open field), if it starts to charge, by elimination, the ECM or associated wiring is bad.

Now, if you decide to go with an external alternator.......Hopefully you gave yourself 6" of wire above.
There are two flavors of regulators, Positive and Negative. One type the alternator field is grounded and you vary the source to determine the charge, the other the Positive is fixed and you vary the ground side. You need the latter. There are usually 3 wires plus a ground. Mount the thing on metal, both for heat dissipation and RF (radio noise) suppression. 1 lead will go to the battery sense wire, another will come from the ignition switch (or ignition activated voltage) If you don't do this, the current flow through the field will drain the battery. and the last goes...............to the 4th wire on the alternator.

If the light bulb works, make a good connection, it will work until you figure out what you are going to do. check the water level, if it is overcharging too much use the tail light instead of the brake light.
Let us know, I'll be off the computer from Tues morn to Wed evening. I'll check in before I leave to see if you're OK.

Regards,

Jim W

It is easier to implement than read.

94Moby 05-16-2011 07:30 PM

I had one of these on my Jeep when I got it:

http://www.alternatorparts.com/exter...nator-kit.html

Presumably to by-pass a failed or faulty ECU. However the headlights would pulsate at night, and the charge to the battery was not what it should have been. I ended up getting a rebuilt ECU from a local retailer, and everything has worked fine since.

Ininkus 05-16-2011 07:58 PM

1 Attachment(s)
I just had to do this to mine. I'm not so great at long descriptions of how to do it, but I made this little diagram. Hope it helps. Mine works great, a steady 14.4 volts.

Like the diagram shows, I left the black mounting block on the back of the Alternator, but bent the tabs and taped them. Oh make certain to mount the voltage regulator so that the case is grounded really well. I did mine on the firewall, grind the paint down.

I'm short for time, sorry to be brief - PM me any questions.

Ininkus 05-16-2011 08:03 PM

One addition: I got the voltage regulator by asking for a mid to late 80's Dodge external voltage regulator. You can even get the pigtail for it, PN: PT173.

smgbsdc 05-16-2011 08:23 PM

That's some assume information guys... I really appreciate it.... I broke down and ordered an reman ecu today... 225 with a life time garuntee.... But I will keep this post invade I ever need it... One more question: I have come across lots of info on this the last few days... My original problem with first ecu was slow start that turned into no start with no CEL... But... I didn't see anything about what causes this somewhat common problem ... Any ideas how this happens in the first place so I can prevent it in the future? Thanks again guys... Awesome write ups and diagrams!!!!!!

Lo_Lo 07-19-2011 03:44 PM

I am blowing alternators and beteries left and right but only when I leave my lights on while it's NOT running. It's overcharging because the computer is shot. What is the best external regulator to get? I'm new to this fixin' my own vehicle stuff so be Gentle :)

Bongi22 11-19-2011 05:42 PM

Quote:

Originally Posted by Ininkus (Post 11553076)
I just had to do this to mine. I'm not so great at long descriptions of how to do it, but I made this little diagram. Hope it helps. Mine works great, a steady 14.4 volts.

Like the diagram shows, I left the black mounting block on the back of the Alternator, but bent the tabs and taped them. Oh make certain to mount the voltage regulator so that the case is grounded really well. I did mine on the firewall, grind the paint down.

I'm short for time, sorry to be brief - PM me any questions.


As I'm in the middle of doing this I found that many of the other references I've seen regarding this has the pin at the apex of the triangle ( or more towards the center of the regulator ) is the one with the 12v switch and have it going to the 3rd pin on the alternator.. Is this diagram accurate to how you installed it?
I've seen messages saying it doesn't matter.. but in 5 or 6 drawings or photos I've seen it has it with the non 12v going to the 4th pin.

Foundrydude 11-19-2011 06:09 PM

I did an external regulator on my ZJ with the same model of alternator and the 2 wires drawn into that diagram are reversed (on the alt) regarding which is keyed 12v and ground. Dunno if it matters.

oldtime_ironman 11-19-2011 06:17 PM

Quote:

Originally Posted by smgbsdc (Post 11553274)
That's some assume information guys... I really appreciate it.... I broke down and ordered an reman ecu today... 225 with a life time garuntee.... But I will keep this post invade I ever need it... One more question: I have come across lots of info on this the last few days... My original problem with first ecu was slow start that turned into no start with no CEL... But... I didn't see anything about what causes this somewhat common problem ... Any ideas how this happens in the first place so I can prevent it in the future? Thanks again guys... Awesome write ups and diagrams!!!!!!

there's a whole write-up in the stickies FAQ up top of your screen. Your ECU was a cheap-n-easy $5 fix. Here's the link with pics!

http://www.jeepforum.com/forum/f12/c...ors-ecu-492597

.

vinvango 02-03-2012 04:40 PM

I just did this to my 1995 wrangler problem was low voltage on volt meter my alternator, battery and grounds all checked out. I did not what to spent 250 for a rebuild ecu or 500 new at the dealers.So I got a voltage reg from advanced auto for a 1980 dodge ram 360 5.8L witch was a 100amp regulator.I figured since my alternator was a 90amp and the two maxi fuses were two 50a it all checked out $21 .It looks just like the one used by Ininkus and what i did was hook up the split wire that goes to the ing to the 40amp ing fuse in the fuse box next to the battery and mounted the reg just behind the battery on the firewall.And as for the original field connectors i just tapedthem up undid the grounds and flipped it 180*. Because of this post i am know back on the road and loveing the jeep again .Only thing know is the engine light is on not a bad thing it's been on since i bought the jeepI'm use to nothing a little length off black electrical tape can't fix .My hat is off to you all ,thank you very much ,all smiles for now VinVanGo


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