Upgraded Voltage Regulator

[mgm1986]

Alright, I am stumped. Issues with flickering lights at higher RPMs. I got a great recommendation from Big_John to upgrade my mechanical voltage regulator using VR706 (http://www.autozone.com/autozone/parts/Duralast-Voltage-Regulator/_/N-5yc1s?itemIdentifier=129965).

I also got a great link from Commando on the mopar charging system. (http://www.mymopar.com/charging.htm)

And now I am confused. Is this a 'plug and play' upgrade when using the VR706 VR? There are two wires on the blade connector, blue and blue/white and one green wire screwed in to the VR. I'd like to keep my alternator as it works fine. In the diagram below it assumes I have a new style alternator. I dropped the new VR in place and now have a constant 12.4 volts at the battery. With the mechanical VR my volts would increase up to 14.8 depending on engine RPM.

How do I upgrade to the VR706 and keep my alternator? Is it possible? :sSig_thanks:

 

[MrMoparCHP]

The VR706 is a plug-n-play upgrade, no changes to the alternator.
This regulator is a direct replacement for the original, it is used with the original single field alternator.

Alan

 

[MrMoparCHP]

The dual field alternator upgrade uses a different regulator and you need to add a piece of wire.


Alan

 

[mgm1986]

The VR706 is a plug-n-play upgrade, no changes to the alternator.
This regulator is a direct replacement for the original, it is used with the original single field alternator.

Alan

Thanks for confirming this!

So why do you think it's not getting the volts above 12.4? Bad ground to the firewall? I was expecting somewhere between 13.5 and 14.5.

 

[MrMoparCHP]

Voltage drop happens everywhere, every connection and piece of wire even the ammeter can contribute. Measure the voltage at the alternator on the primary terminal. The next point is the bulkhead black wire. After that the ammeter in/out then back to the bulkhead red wire. From there the fusible link and finally the battery.


Alan

 

[mgm1986]

Voltage drop happens everywhere, every connection and piece of wire even the ammeter can contribute. Measure the voltage at the alternator on the primary terminal. The next point is the bulkhead black wire. After that the ammeter in/out then back to the bulkhead red wire. From there the fusible link and finally the battery.


Alan

Good point, I will start tracking it down this weekend and this is helpful to know what to look for. Step one is to put the old mechanical regulator on and measure again. Immediately before removing it, measuring from the batter, I had 12.5 volts at idle and anywhere from 13.5+ when upping the RPMs. I know the bolts holding the VR to the firewall don't get as tight as they did from the factory because the holes are mostly stripped so I will rethread those holes and make sure I get a solid ground.

 

[Big_John]

You need a good ground for the regulator to work correctly.

Check your other connections too.

 

[65sporty]

you may want to add a ground wire from the regulator to back of cyl head

 

[mgm1986]

I dropped the old VR in place and it started charging again. It's not that the old mechanical VR didn't charge but it caused a lot of fluctuation which caused the lights to flicker. I made sure all my connections were solid and didn't have a short somewhere. I rethreaded the holes in the firewall and hooked up the new VR. Still nothing.

So I went and bought another VR706 and dropped it in, problem solved!! Wasted about an hour troubleshooting a brand new part but it forced me to correct the stripped holes the VR screws into on the firewall and no more flickering lights and a solid 13.8 charge at cruising RPM's. it also forced me to have the battery tested, which tested fine so that makes me feel better too.

Thanks to all of you for the help!

 

[MrMoparCHP]

Same here, I got stranded 2 hours from home looking for one after recently installing one, that was when I chose to convert to the later style.


Alan

 

[mgm1986]

Back to square one. Last Friday I took the car out and found it was no longer charging. Silver lining, it was better to find out before I tried to take her to Carlisle!

I thought the VR went bad again so I swapped in a new one and still nothing. I tried to have my alternator bench tested and believe it or not, four different parts stores (Pep boys, 2 AutoZones and advanced auto) couldn't figure out how to actually use the equipment so I decided to just replace it and see what happens. Nothing.

New 45amp alternator from NAPA, three different VR706 voltage regulators and a new NAPA battery. I got nothing. The only MOD I have done is to bypass the firewall charging circuit with an upgraded 10gauge wire with fusible link from the alternator to the power block next to the battery. Everything worked beautifully for three weeks then nothing.

I guess I need to check all my behind the dash connections and the wiring under the hood because I am stumped. Good thing I enjoy fixing her as much as I do driving her!

 

[bluefury361]

Is the battery actually going dead .........? A quick check is to remove the positive battery cable while the engine is running. should stay running if charging.

Could be the guage is defective.

 

[mgm1986]

Is the battery actually going dead .........? A quick check is to remove the positive battery cable while the engine is running. should stay running if charging.

Could be the guage is defective.

The battery is going dead over time. I knew it wasn't charging because it was slow to crank. As far as the Ammeter in the car, it doesn't work, I use an electronic voltmeter that plugs to the cigarette lighter. This usually shows .5 volts lower than my handheld voltmeter, but it works. Right now, when running, I get 12.47 volts.

I have been told to never disconnect the battery to check if the system is charging, but this was on newer cars. Is this okay to do when no OBD computer is present?

 

[MrMoparCHP]

You might want to think about upgrading to the 70+ style regulator. I went through three different regulators on my car the replacements are junk. Two of those had me stranded a couple hours from home, the second one was the final straw.

The upgrade is simple.
1. Get a later alternator (70+) or add a brush to your existing one.
2. Get a later regulator (70+)
3. Get the pigtail.
4. Get about 3’ blue wire and some connectors.

Ignore the ignition module

1. Cut the terminals off for the old regulator.
2. Splice the green from the pigtail to the green on the harness.
3. Splice the new blue wire to the existing blue wire(s) and the blue wire on the pigtail.

Done, it is that simple.



Alan

 

[mgm1986]

You might want to think about upgrading to the 70+ style regulator. I went through three different regulators on my car the replacements are junk. Two of those had me stranded a couple hours from home, the second one was the final straw.

The upgrade is simple.
1. Get a later alternator (70+) or add a brush to your existing one.
2. Get a later regulator (70+)
3. Get the pigtail.
4. Get about 3’ blue wire and some connectors.

Ignore the ignition module

1. Cut the terminals off for the old regulator.
2. Splice the green from the pigtail to the green on the harness.
3. Splice the new blue wire to the existing blue wire(s) and the blue wire on the pigtail.

Done, it is that simple.



Alan

Thank you very much, Alan! The last thing I need to replace is the wiring, everything else is new. I will keep this is an option though if all else fails. I am finding your statement about the junk electronic VR to be true.

 

[70bigblockdodge]

They make a electronic version of old electromechanical regulator, I have not tried it personally

 

[MrMoparCHP]

They make a electronic version of old electromechanical regulator, I have not tried it personally

That is what the VR706 is and I had two bad ones. If you choose to run these I'd recommend keeping a spare in the trunk.


Alan

 

[mgm1986]

That is what the VR706 is and I had two bad ones. If you choose to run these I'd recommend keeping a spare in the trunk.


Alan

Yes, exactly. I have three of these on hand and none of them are getting me to a charge state so I suspect the problem is in the wires somewhere. Really wish I had AC in the shop though while digging through the wireing, it is hot outside!

 

[MrMoparCHP]

Yes, exactly. I have three of these on hand and none of them are getting me to a charge state so I suspect the problem is in the wires somewhere. Really wish I had AC in the shop though while digging through the wireing, it is hot outside!

A quick way to test the voltage regulator is to put your meter on the battery and put a jumper bypassing the regulator.
You should see the voltage climb, take the jumper of and it should stop and settle back to about 14v


Alan

 

[mgm1986]

A quick way to test the voltage regulator is to put your meter on the battery and put a jumper bypassing the regulator.
You should see the voltage climb, take the jumper of and it should stop and settle back to about 14v


Alan

Jumper bypassing the regulator; Do you mean disconnect the blue wire from the VR and disconnect the green wire from the VR and jump them together?