Painless Harness/Voltage Regulator/Alternator issues with Retrosound

[PilotDub]

I had a Painless harness installed on my 74 Bronco at the same time I had a retrosound radio installed. The sound system folks said they could do the harness and they did…eliminating the parasitic drain I had previously experience.

Anytime I reach 1500-2000 RPMs, the speakers quit playing. The radio stays on, but the speakers quit. I’ve asked to see if the installer grounded the the frame which could cause that.

In testing, I noticed pretty high voltage (like 16.5) on the battery when the engine is revved up a bit. Would that indicate a faulty voltage regulator? I think so, but am checking for the wisdom here. Anything else I should test or do before just replacing the VR?

Related, is it better to replace the alternator/VR with a single wire G3?

Thanks in advance for any thoughts!

 

[DirtDonk]

Yes, it could be the regulator. But it also could be wiring, not getting sufficient voltage to the correct places.
First, make sure the regulator is solidly bolted to the body. And make sure you have a good body ground. Or Grounds… One directly from the Battery to the body, and then another from the back of the engine to the firewall.
Where is your regulator mounted?

Does your regulator have three or four wires connected to it?

Pull the four bay, three wire connector off of the regulator and test for power at different locations. Or, if you have slim enough probes on your voltmeter, you could probably test this with the regulator connector in place.
With the engine off, there should be no voltage on the orange “F“ wire.
With the key on, there should be 12 V on the “S“ wire.
Any time, key on or off, the yellow “A“ wire should have 12 V at all times. In fact, it should have exactly battery voltage. Whatever that happens to be at that moment.

You can check output on the orange field wire with the engine running, but I’m not sure what the values should be at any given voltage output.
Maybe someone here knows.

 

[DirtDonk]

Regarding the 1G versus 3G aspect of your question, there is almost no scenario under which the 3G isn’t a better setup.
It’s a little extra work up front, the alternators are probably always going to be more expensive, but it’s a more modern, more powerful unit, with generally a more stable voltage output.

Can’t truthfully say that they are more reliable. The 1G is also reliable as a stone, as long as it’s a good quality product.
But that’s the catch these days. How do you get a good one of anything from a parts store.
No matter what, you usually don’t get it by buying the least expensive one.

A downside to any more powerful alternator, is the potential for squealing fan belts.
Not a problem with a modern serpentine belt setup, but a very distinct possibility with original V-belts.
There are ways around that, sometimes with dual pulleys, sometimes with larger diameter alternator pulleys, sometimes using the smaller output 3G (95 amp instead of 130 amp) and things like that.
But it’s usually a worthy upgrade.

A voltage regulator is easy and inexpensive if it turns out to be the problem. On the other hand, if it turns out that the alternator is faulty, now is the perfect time to upgrade to a 3G.

 

[DirtDonk]

Just make sure that if you decide to go that way, you let us know so we can run through the wiring upgrades that are necessary.
You won’t be able to use your ammeter anymore, and the black wire gets re-oriented. You’ll need a new charge wire.
Vendors like us at Wild Horses carry kits like that, or you can make your own.

 

[73azbronco]

you need to go 3 or 4 G. Chasing voltage regulator issues on 50 year old vehicles will convince you.

 

[Jdgephar]

FYI - the amp is likely shutting down due to excessive voltage. Fix your voltage issue and radio should work fine again. My friends Corvair did the same thing.

 

[DirtDonk]

And is this harness the Bronco specific harness? Or a generic Painless?

 

[PilotDub]

And is this harness the Bronco specific harness? Or a generic Painless?

Thanks for all the helpful feedback! I used the Painless harness. I’ve ordered a new regulator already. Will go do the tests you laid out and get back.

I'm likely to do the 3 or 4 G upgrade at some point. Soon if if the simple VR swap doesn’t correct it. If that seems to work, I’ll likely enjoy driving her through the summer and do that next winter.

I’ve also got dual fuel tanks, but only use one as the other leaks. Previous owner installed an electronic tank switch and removed the manual. Fuel gauges don’t work either, so all that is going to need to be addressed.

 

[DirtDonk]

Which tank are you using?
If the rear/main tank, it’s easy to find out if it’s the fault of the dash switch by using the bypass feature.
It’s not really a “feature” as much as it is just using the original wiring for a single tank.
Locate the Orange wires and unplug them from the switch, then plug the two 90’s into each other. Switch bypassed.