Ampmeter steady! lights work! SBC alternator was the issue!

[oldracerguy]

I have been chasing this gremlin for some time and now all is good with my whole electrical system.

1. My ampmeter was always jumping around for no apparent reason.
2. My headlights were always going from dim to very bright while driving, not bump related. Eventually they burned out at the same time, and the high beams.
3. I blew a 25 amp fuse that triggers my relay for my electric fan last week and overheated and boiled over.
4. I put a digital voltmeter on my alt and saw it spiking up to 16.5 volts. I brought it in to Lloyds Electric shop and they put it on the machine to test. Sure enough, after it warmed up it started spiking. $25.00 later and I walked out with a new regulator part in my alternator.

And the results are:

1. Lights work perfect and are steady in brightness.
2. Ampmeter is steady and only moves slighly above the middle when I am on the gas or have lights,blowers, etc. on. Yaaay!
3. No more blowing fuses that trigger my electric fan when my temp reaches 180.
4. My idle for the first time is now down to 700. Before I always had to blip the throttle as it seemed like the choke was always on. I can't explain this one but I have a brand new Holley TA 670 on it and it would always climb back up to 1,500 rpm even when it was warm. I have everything adjusted to get it to idle much lower. Maybe the voltage issues were creating issue with the electric choke?

Anyway, it wasn't a bad ground, switch, corrosion, etc. It was the built in VR in my single wire Delco alternator. Even though my factory voltage regulator is still installed and is protecting some other circuits, this one was obviously tied into my headlights, ampmeter, etc. Life is good!

 

[dargreg]

Hey guess what,now you know all your grounds are OK and the harness is good.and have a real good heads up on your elec. system,always works that way.

 

[bsevans]

I have been chasing this gremlin for some time and now all is good with my whole electrical system.

1. My ampmeter was always jumping around for no apparent reason.
2. My headlights were always going from dim to very bright while driving, not bump related. Eventually they burned out at the same time, and the high beams.
3. I blew a 25 amp fuse that triggers my relay for my electric fan last week and overheated and boiled over.
4. I put a digital voltmeter on my alt and saw it spiking up to 16.5 volts. I brought it in to Lloyds Electric shop and they put it on the machine to test. Sure enough, after it warmed up it started spiking. $25.00 later and I walked out with a new regulator part in my alternator.

And the results are:

1. Lights work perfect and are steady in brightness.
2. Ampmeter is steady and only moves slighly above the middle when I am on the gas or have lights,blowers, etc. on. Yaaay!
3. No more blowing fuses that trigger my electric fan when my temp reaches 180.
4. My idle for the first time is now down to 700. Before I always had to blip the throttle as it seemed like the choke was always on. I can't explain this one but I have a brand new Holley TA 670 on it and it would always climb back up to 1,500 rpm even when it was warm. I have everything adjusted to get it to idle much lower. Maybe the voltage issues were creating issue with the electric choke?

Anyway, it wasn't a bad ground, switch, corrosion, etc. It was the built in VR in my single wire Delco alternator. Even though my factory voltage regulator is still installed and is protecting some other circuits, this one was obviously tied into my headlights, ampmeter, etc. Life is good!

Dude, why in the world do you have an external VR still active in the system? The internal VR should be the only one regulating the voltage. You've got the Internal VR controlling the voltage the battery sees and the external VR is needed to regulate the voltage which is already regulated. Sorry, I need an aspirin.

 

[bsmith123]

vr

x2

you should trace it out, I doubt the external vr is still in the system
if it is we can tell you how to bypass it and have everything still work as it should there is no need for 2

although wiring can be an issue, its a pretty sure bet when you get over 16 volts the VR is the culprit as opposed to undercharging but its good to post up the results so others can see what the final fix was ---chances are someone else will have it eh?

 

[oldracerguy]

Dude, why in the world do you have an external VR still active in the system? The internal VR should be the only one regulating the voltage. You've got the Internal VR controlling the voltage the battery sees and the external VR is needed to regulate the voltage which is already regulated. Sorry, I need an aspirin.

I have no idea why I have the external voltage regulator still in the system. The prior owner had a shop do the sbc conversion. I assume the external factor vr on the firewall is still active because it has power going to it. I agree that it is not necessary as the voltage is already regulated. Does anyone have an easy way to make sure my feed from the alternator is the only feed and take the external vr out of play? Or should I just leave it becuase it is not hurting anything?

 

[bsmith123]

vr bypass

https://forum.ih8mud.com/40-55-series-tech/223160-alt-upgrade.html


have a read here--check out pinheads post

just search on alternator upgrade or voltage regulator and others will come up