Voltage Regulator Advice

Looking to upgrade the VR on my 68 bird. Have read various postings on several sites and seems to be a mixed bag. I need to get rid of that 12 - 16 volt cycling. car looks like a strobe light and not so sure it isn't some of my engine surging / exhaust backfire issues. Anyway, have a Tuff-Stuff 100 amp alternator, (period correct) with an MSD 6AL box, MSD billet distributor, (no vacuum advance) and a who know's who's solid state, 2 wire switching regulator. Also no Bulkhead Connector, have Ron Frances wiring and everything is direct. Looking to go to a constant voltage type and the Mopar Performance blue box or something like it looks to be a good choice. It's deemed a race only part but a constant 13.5 V output isn't bad. Many other postings I've read are mixed being from "used it for years on the street with no problems" to "Major melt down" Thought I'd throw this out to the FBBO folks for there thoughts. Thanks Dale

I've got a period looking solid state pre 69 VR and a 65 AMP autozone with no dimming (950 in gear idle, which helps). Maybe the Alt. isn't putting out 100 or close to that at idle?

Don't believe it to be a current issue, as it would just stop switching at the control point (16V) and hang at the voltage it could produce (most likely battery voltage) at the current the alternator could produce at that RPM. Can't have volts without current and can't have current without volts.

you can get a stock looking regulator that is electronic style without the points at most any parts store, or you can get one from here

http://www.4secondsflat.com/regulator_tech.html

The original reg was on off and with a 100 amp alt is not good
You need variable field control to smooth the voltage out go electronic regulator

Dale, are you using the VR that came with the Ron Francis kit? I have one in my 69 RR, using a standard mopar alternator (dual field) and I had some issues with not getting constant voltage. I had it wired as stated from Ron Francis. I did a bunch of research on line and discovered 2 things..

1. the Ron Francis regulator is a SS Ford style (if it's the same as mine, it should look like this http://www.partsgeek.com/2znktmh-fo...ek+Bing&gb=pp&utm_term=Ford+Voltage+Regulator )

2. It is a great regulator (dare I say better design than mopar) but Ron has it wired in a bad way. The best part about the ford charging system vs mopar is the use of Remote Voltage Sensing. I have a thread here on the forum that went through my trials and tribulations and has a link to a site that nailed how to rewire to use the VR properly. In a nutshell the issue for me was the way RF had it wired was sensing voltage directly at the alternator, which was causing it to produce voltage either over or under the needed amount elsewhere in the system (like at the dash gauges, headlamps, ect..) the key is to wire it to sense voltage at a centralized junction point, equally distant as far as wire runs, from all of the major items, which usually mean somewhere close to the firewall bulkhead conn (which you probably don't have if you have a RF kit like me). I have a positive power stud mounted to the firewall that I run main power to most systems from... s, 4 feet to batt, 6 feet to alt, 4 feet to dash, ect.. this is where I sense the voltage to control the regulator.

The benefit is that it reduces the voltage drop over long runs of wiring that will cause the regulator to over or under produce. BTW.. Once I made this change, the voltage now appears +/- .3V almost everywhere in the car!

One other major component of this issue is the resistance value across the wiring/connectors, so make sure you have good clean connections and good crimps.

BTW, I have an MSD 6A, MSD dist as well.

Your 100 amp alternator should be fine, as the system will only use the amps it needs.

I know I might be shunned, but mopar's charging system and wiring are a weak link in their design compared to GM/Ford.. If you don't mind non-orig.. stick with the ford style VR, just wire it to take advantage of the remote volt sensing and it should work better than stock.

Here's my thread..

http://www.forbbodiesonly.com/mopar...aced-alternator-now-voltage-is-too-high-15-5v

Which Tuff Stuff alt did you get? Mine has the reg built into it so there is no need for another regulator. especially with the rest of the stuff you have.

dburnett6263 said:

Looking to upgrade the VR on my 68 bird. Have read various postings on several sites and seems to be a mixed bag. I need to get rid of that 12 - 16 volt cycling. car looks like a strobe light and not so sure it isn't some of my engine surging / exhaust backfire issues. Anyway, have a Tuff-Stuff 100 amp alternator, (period correct) with an MSD 6AL box, MSD billet distributor, (no vacuum advance) and a who know's who's solid state, 2 wire switching regulator. Also no Bulkhead Connector, have Ron Frances wiring and everything is direct. Looking to go to a constant voltage type and the Mopar Performance blue box or something like it looks to be a good choice. It's deemed a race only part but a constant 13.5 V output isn't bad. Many other postings I've read are mixed being from "used it for years on the street with no problems" to "Major melt down" Thought I'd throw this out to the FBBO folks for there thoughts. Thanks Dale

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I've had enough bad experience with the cheap junk on the market to avoid them permanently. I use this one on vehicles I'm not converting to the '70-up style charging circuit. Still made in the USA (at least last time I bought one, not too long ago). Looks slightly different to the original, bolts and connects right in, easily handles the rotor draw of a high-output alternator, sits there and does a good job of its job for years.

Thanks for all the info. I ordered the constant voltage Mopar Performance blue box from Jegs, little over 30 bucks with free shipping. Gonna give it a try. When I bought the Tuff Stuff 100 Amp alt I was trying to stay somewhat period correct so went with the external VR. But as my build progressed I ended up more Resto-Mod so, woulda, coulda, shoulda, gone with an internal VR.
I have checked for ground loops and good steady voltage through out. All is as it should be. I don't recall a VR coming with my Ron Frances kit, used the solid state switcher that came with the car. Looked to be brand new. Dale

dburnett6263 said:

Thanks for all the info. I ordered the constant voltage Mopar Performance blue box from Jegs, little over 30 bucks with free shipping.

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"Constant voltage" is a bogus/nonsense claim. Under that regulator's blue powder coating is a VR-128 regulator like the one I linked. Make very sure you scrape away enough of the blue to get a good ground for the regulator case through the mounting screws. If you don't, the regulator will full-field the alternator and large swaths of your electrical system will burn up.

woulda, coulda, shoulda, gone with an internal VR

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Not me, brother! I like to be able to quickly and easily replace the voltage regulator without having to swap the alternator.

Thanks Slant, will do the paint scrape thing.

I've got a new problem. My voltage is about 16 at idle and up to 18 at speed. I have a new alt, battery, ballast resistor and voltage regulator. I disconnect the VR and all charging stops. When connected I have overcharge and the VR gets really hot. Maybe a bad ground at the VR?

Lot of people here know a lot of stuff. Had trouble with over charging and after reading thru the post with possible fixes repaired it with first try. Same old problem.........faulty ground.

There are MANY places that could be badly grounded. I had to replace my fuse-box, and one of the studs was loose in my amp-meter....so we bypassed it.