High voltage regulator fixed! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bud45 · 01-07-2005, 11:42 PM

After replacing my external regulator under warranty (went with original GM) after the replacement went nuts & cranked out 17 VDC, the replacement went nuts, too. I spent the day checking my electrical system, instead of hunting & fixed (1) wire end...I then checked the regulator output itself at the battery and at the cigar lighter...15+ volts, and once it too spiked at 17+ volts! Lights flicker like crazy, too and I burned up a Ham radio that cannot be repaired....

Needless to say, I grabbed my book & found it could be readjusted for the proper voltage output by bending the tab holding the spring at the actual regulator in the unit- wish I could post pictures, but I can't, so I'll describe it best I can:

Remove the 2 screws that hold the cover on & remove the cover. On the side closest to the radiator, you'll see a spring between the regulator point "finger" and another "finger" solidly fastened to the frame of the voltage regulator frame. CAREFULLY bend the frame "finger" to: A. lessen tension on the spring, lowering voltage, or B. tighten spring tension to increase voltage. Note: a little can go a long way! Note 2: you might want to do the bending with the truck's engine switched "off", just in case.

Now, my voltage is staying at a constant 13.8VDC at both points I tested and the lights are no longer flickering.

YES, for you one-wire alternator advocates, I AM going to convert it in the near future, but I thought I'd present this as a "fix" for those folks who need to stabalize their voltage UNTIL they can get to that one-wire set-up!

BTW, my local Advance Auto guy said a high-amp alternator (90 amps, +/- a few) can be had for between $35-$45, and he does the change-over all the time....very soon, I'll have that extra "umph!" for my Ham radios while I drive!

**'68OrangeSunshine** · 01-08-2005, 06:42 AM

Had that same runaway voltage gripe on my '71 Jimmy a couple of years ago. I had to replace the headlamp/engine wiring harness before the problem went away. [A lifting ground on the farside headlights was the initial gremlin, but a 12 volt solar panel trickle-charging thru the cigar lighter socket -- and spiking to 17 volts in the summer AZ sun may have blown a few diodes].
Back in the day the OEM AC/Delco ext. voltage regulators had set screws so you could manually adjust voltage and charging rates with the motor running. Check out the illustrations in the Chevy Truck Chassis Service Manuals. Today's replacements don't have that feature. God forbid somebody's long hair should get caught in the fanblades and their next-of-kin should sue Checker-Zone. So now it's considered a throw-away item. I've got a milkcrate full of spent Ext regulators. Maybe we could set up a test jig so they could be re-tweaked right?
Sorry to hear about your ham rig. What was it? I'm not an amatuer but I used to run CBs a lot.

bud45 · 01-11-2005, 11:22 PM

It was a handy talkie, a Kenwood TH215A 2-meter (144-148 MHz) synthesized radio- worked good @ 5 watts into a 5/8~ antenna into the local repeaters...now I'm using an older Kenwood TR7850 40 watt rig, but I'm careful to switch it on & off at the appropriate times; I've noticed that it'll sometimes lose it's memory when switching the ignition off, so I think I may have a bad connection somewhere there. I've got to install my multi-outlet +/- connector on my wiring direct from the battery- all I have on that pigtail now is my 10/12-meter Uniden HR2600...THEN I can get the TR7850 off the cigar lighter.

That TH215A was a GOOD radio- called Kenwood, they said throw it away & buy another....

**'68OrangeSunshine** · 01-12-2005, 05:27 AM

I still have a pair of Johnson Messenger CBs. Tube type with a buzzer creating AC. One's a Messenger I (Whiteface) 5 channel and the other a Messenger II(Blackface) w/10 chrystals. The advantage is their output is 5 watts, not 5 in and 3.5 out. The blackface has a bootleg switch that bypasses a resistor in the final and it will put out 10 watts when engaged. Used to run one in the pickup, long ago. Also bought a 40 channel solid state Messenger III from a trucker in the '80s to complete the collection. Good thing about low tech is that it's field-repairable. On the Stepside I still have a Hustler 90* breakdown mast with a stub loaded stick on top. It's as tall as a 1/4 wave whip. [11 meter; 27Mhz]
Anyway, for an accessory power leg I've thought I would run a 10 or 12 ga red line from the pass side fender terminal (off the battery) thru the firewall and into a 3-cigarplug outlet box under the glovebox. A terminal strip adjacent could be used for more permanent applications. Just be sure to run a fuse inline with the feed circuit. 3s&8s.

bud45 · 01-15-2005, 11:50 PM

Rest assured, ALL my radios are individually fused! Fuses take care of over-amperage, but not overvoltage...I've been kicking around the idea of building a high-amperage 13.8vdc supply to put inline on the lines I have coming in, but haven't gotten the physical layout done yet. Probably will have to daisychain numerous 1.5 amp transistors on a heat sink, or try to find a heavier replacement (much more $$$!). What it'll do is take up to 16-18vdc and clamp it at 13.8vdc....

Man, those old Johnsons were baaaad!

I had several, but traded them for some other stuff. BTW, I have some old junk(?) transistor rigs from the past I'm about to throw out (good for parts) unless someone in the repair biz on old radios would like 'em...know anyone?

**'68OrangeSunshine** · 01-16-2005, 06:28 AM

Quote:

Originally Posted by bud45

Rest assured, ALL my radios are individually fused! Fuses take care of over-amperage, but not overvoltage...I've been kicking around the idea of building a high-amperage 13.8vdc supply to put inline ...

Man, those old Johnsons were baaaad!

I had several, but traded them for some other stuff. BTW, I have some old junk(?) transistor rigs from the past I'm about to throw out (good for parts) unless someone in the repair biz on old radios would like 'em...know anyone?

Aircraft [Military, that is] used to have at least 3 circuits. An AC Busbar and 2 28 VDC busbars. Sometimes also an emergency busbar with a small 28 volt batt, with guns, landing lights, standby ADI, ejection package and emergency radio, discrete from other circuits. In these old Chevy trucks a similiar set-up would include a separate batt, with stereo, aux lights, comm gear, emergency start. And like the aircraft system it could be independent of the regular harness.
As far as old fluid-state junk? I'm really a time traveler and I'm stuck in this period because the Klystron khryptonizer in my atavachron is busted and they don't make that tube anymore. I'm always hoping I'll find a mint one and can return to my own century.(just kidding.) But I do like to collect old stuff. I'm in Tucson AZ, 85704. PM me if you want to trade.

01-07-2005, 11:42 PM	#1
bud45 Registered User Join Date: Nov 2004 Location: Satsuma, AL Posts: 72	High voltage regulator fixed! After replacing my external regulator under warranty (went with original GM) after the replacement went nuts & cranked out 17 VDC, the replacement went nuts, too. I spent the day checking my electrical system, instead of hunting & fixed (1) wire end...I then checked the regulator output itself at the battery and at the cigar lighter...15+ volts, and once it too spiked at 17+ volts! Lights flicker like crazy, too and I burned up a Ham radio that cannot be repaired.... Needless to say, I grabbed my book & found it could be readjusted for the proper voltage output by bending the tab holding the spring at the actual regulator in the unit- wish I could post pictures, but I can't, so I'll describe it best I can: Remove the 2 screws that hold the cover on & remove the cover. On the side closest to the radiator, you'll see a spring between the regulator point "finger" and another "finger" solidly fastened to the frame of the voltage regulator frame. CAREFULLY bend the frame "finger" to: A. lessen tension on the spring, lowering voltage, or B. tighten spring tension to increase voltage. Note: a little can go a long way! Note 2: you might want to do the bending with the truck's engine switched "off", just in case. Now, my voltage is staying at a constant 13.8VDC at both points I tested and the lights are no longer flickering. YES, for you one-wire alternator advocates, I AM going to convert it in the near future, but I thought I'd present this as a "fix" for those folks who need to stabalize their voltage UNTIL they can get to that one-wire set-up! BTW, my local Advance Auto guy said a high-amp alternator (90 amps, +/- a few) can be had for between $35-$45, and he does the change-over all the time....very soon, I'll have that extra "umph!" for my Ham radios while I drive!

01-08-2005, 06:42 AM	#2
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,357	Had that same runaway voltage gripe on my '71 Jimmy a couple of years ago. I had to replace the headlamp/engine wiring harness before the problem went away. [A lifting ground on the farside headlights was the initial gremlin, but a 12 volt solar panel trickle-charging thru the cigar lighter socket -- and spiking to 17 volts in the summer AZ sun may have blown a few diodes]. Back in the day the OEM AC/Delco ext. voltage regulators had set screws so you could manually adjust voltage and charging rates with the motor running. Check out the illustrations in the Chevy Truck Chassis Service Manuals. Today's replacements don't have that feature. God forbid somebody's long hair should get caught in the fanblades and their next-of-kin should sue Checker-Zone. So now it's considered a throw-away item. I've got a milkcrate full of spent Ext regulators. Maybe we could set up a test jig so they could be re-tweaked right? Sorry to hear about your ham rig. What was it? I'm not an amatuer but I used to run CBs a lot. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

01-11-2005, 11:22 PM	#3
bud45 Registered User Join Date: Nov 2004 Location: Satsuma, AL Posts: 72	Ham rig It was a handy talkie, a Kenwood TH215A 2-meter (144-148 MHz) synthesized radio- worked good @ 5 watts into a 5/8~ antenna into the local repeaters...now I'm using an older Kenwood TR7850 40 watt rig, but I'm careful to switch it on & off at the appropriate times; I've noticed that it'll sometimes lose it's memory when switching the ignition off, so I think I may have a bad connection somewhere there. I've got to install my multi-outlet +/- connector on my wiring direct from the battery- all I have on that pigtail now is my 10/12-meter Uniden HR2600...THEN I can get the TR7850 off the cigar lighter. That TH215A was a GOOD radio- called Kenwood, they said throw it away & buy another....

01-12-2005, 05:27 AM	#4
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,357	I still have a pair of Johnson Messenger CBs. Tube type with a buzzer creating AC. One's a Messenger I (Whiteface) 5 channel and the other a Messenger II(Blackface) w/10 chrystals. The advantage is their output is 5 watts, not 5 in and 3.5 out. The blackface has a bootleg switch that bypasses a resistor in the final and it will put out 10 watts when engaged. Used to run one in the pickup, long ago. Also bought a 40 channel solid state Messenger III from a trucker in the '80s to complete the collection. Good thing about low tech is that it's field-repairable. On the Stepside I still have a Hustler 90* breakdown mast with a stub loaded stick on top. It's as tall as a 1/4 wave whip. [11 meter; 27Mhz] Anyway, for an accessory power leg I've thought I would run a 10 or 12 ga red line from the pass side fender terminal (off the battery) thru the firewall and into a 3-cigarplug outlet box under the glovebox. A terminal strip adjacent could be used for more permanent applications. Just be sure to run a fuse inline with the feed circuit. 3s&8s. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

01-15-2005, 11:50 PM	#5
bud45 Registered User Join Date: Nov 2004 Location: Satsuma, AL Posts: 72	Fused outlets Rest assured, ALL my radios are individually fused! Fuses take care of over-amperage, but not overvoltage...I've been kicking around the idea of building a high-amperage 13.8vdc supply to put inline on the lines I have coming in, but haven't gotten the physical layout done yet. Probably will have to daisychain numerous 1.5 amp transistors on a heat sink, or try to find a heavier replacement (much more $$$!). What it'll do is take up to 16-18vdc and clamp it at 13.8vdc.... Man, those old Johnsons were baaaad! I had several, but traded them for some other stuff. BTW, I have some old junk(?) transistor rigs from the past I'm about to throw out (good for parts) unless someone in the repair biz on old radios would like 'em...know anyone?



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