Delco Remy 918C Regulator replacement

[Cadillac Jack 82]

Guys:

I'm at my whits end.  After numerous tests I finally pulled the generator plus the regulator on my 1937 Lasalle and took it over to the shop that rebuilt my generator.  They said the output on the generator was fine however they couldnt get the regulator to do anything other than click.  The regulator that was on the car when I bought it and the one I replaced was Delco Remy 1118213.  They're next to impossible to find.  My question is are there any other types of regulators that will work with the Delco Remy 918C generator.  If so what part number do I look for?  I'd like to try and order a new regulator ASAP as I have a car show on Sat (provided it doesnt rain).  Thanks!

[bcroe]

I thought you said it was working, no dimming, good voltage, did
it quit? 

Looks like there are 2 wiring DRAWING drawing versions, one with
an ammeter and one without.  However neither shows a COMPLETE
picture of yours.    Bruce Roe

[Cadillac Jack 82]

It seemed to be charging but it was a very low charge.  I attempted to adjust it and it just quit.

[J. Gomez]

It seemed to be charging but it was a very low charge.  I attempted to adjust it and it just quit.

Tim,

Delco Remy site shows VR 1118315 as an equivalent replacement for the 1118213, maybe the 8315 would be more predominant to be found on eBay. 

Good luck..!

[harry s]

Tim, I have a used regulator that I'm pretty sure is right for your LaSalle. I can't find a number but is a Delco. You are welcome to try it and see if it works. You can pick it up whenever convenient or if you are coming to the Capitol show I can bring it.      Harry

[Jay Friedman]

My copy of the Hollander's Interchange Manual, 16th edition, shows the Delco Remy 1118204 voltage regulator as being standard equipment for a '37 LaSalle.  It also says D-R 5806, 5831 and 1118230 will fit and work.

[Cadillac Jack 82]

Guys:

I was able to determine that the regulator that was on the car was the wrong one.  Its a regulator thats meant for a 1937-39 Buick with a negative ground.  I was able to find a NOS 1118204 regulator (correct for my year) on Ebay and it should be arriving today.  With a little luck I should hopefully be out of the woods on this issue.  Thanks to everyone who chimed in!

[bcroe]

Of course the regulator varied with voltage and gen current rating.  But
the gen field could also be connected to either the +output stud, or
to ground.  Unless the reg has a permanent magnetism inside, I would
not expect it to be sensitive to polarity.  Bruce Roe

[jackworstell]

Bruce   

      Back in the    30s   40s  and maybe into the 50s    Delco Remy manuals
had a lot to say about using regulators with the correct polarity.     Many DR regulators even had
"N"  or  "P"   stamped into the mounting flange to help insure proper application.....I have a few
of these kinds of regulators stashed away.

I don't know about other manufacturers.

Something about wrong polarity application would affect the cut-out relay
……..sharply decrease the life of the points and also cause clattering.
Perhaps these are not two separate things   i.e.  the chattering caused by
deterioration of points ?   I don't know.

More modern regulators were not polarity sensitive....I think in part because of improved
materials used in the points of the cut-out relay

I never did completely understand this  but when dealing with the older regulators I
follow Delco Remy advice.

Jack Worstell      jlwmaster@aol.com

I have some of the pertinent   DR literature   if you are interested

[bcroe]

Bruce         Back in the    30s   40s  and maybe into the 50s    Delco Remy manuals
had a lot to say about using regulators with the correct polarity.     Many DR regulators even had
"N"  or  "P"   stamped into the mounting flange to help insure proper application.....I have a few
of these kinds of regulators stashed away.

I don't know about other manufacturers.

Something about wrong polarity application would affect the cut-out relay
……..sharply decrease the life of the points and also cause clattering.
Perhaps these are not two separate things   i.e.  the chattering caused by
deterioration of points ?   I don't know.

More modern regulators were not polarity sensitive....I think in part
because of improved materials used in the points of the cut-out relay

I never did completely understand this  but when dealing with the
older regulators I follow Delco Remy advice.

Jack Worstell      jlwmaster@aol.com
I have some of the pertinent   DR literature   if you are interested

Jack, Thanks for the update.  I was thinking in terms of a chart of
the performance factors, with one or several reg numbers for each set
like
6V        12V      BATTERY VOLTAGE
35A       65A     GENERATOR CAPACITY
GND      +        FIELD RETURN PATH
+GND   -GND    SYSTEM POLARITY

So the reg polarity does matter, must be a magnetic bias in a relay,
guess an arc suppression arrangement could also be the reason.  All
these factors make more reg types necessary.  At least, it is possible
to magnetize a generator for the operational polarity. 

However, the last generator here went away decades ago, so I am
never going to get any more hands on.  thanks, Bruce Roe

[Cadillac Jack 82]

My issue has been resolved although I think its charging a little on the high side.  I read 6.7 to 7.5 volts with all accessories running.  I assume my voltage coil is adjusted a bit too high?

[Glen]

My issue has been resolved although I think its charging a little on the high side.  I read 6.7 to 7.5 volts with all accessories running.  I assume my voltage coil is adjusted a bit too high?

In my experience lead acid batteries need to be charged with 2.3 volts per cell.  That comes to 7.1 volts for a 6 volt battery and 14.2 for a 12 volt. 

I have been working on a voltage regulator for a 1944 Whitcomb.  I bought a solid state regulator but I found it had the wrong polarity for the field.  One side of the field is connected to the negative lead of the generator.  If the field is powered from the negative side there will be no current flow in the field and the generator will not build up voltage. 
Now I guess I have to build the regulator from scratch. 

[bcroe]

In my experience lead acid batteries need to be charged with 2.3 volts per cell.  That comes to 7.1 volts for a 6 volt battery and 14.2 for a 12 volt. 

I have been working on a voltage regulator for a 1944 Whitcomb.  I bought a solid state regulator but I found it had the wrong polarity for the field.  One side of the field is connected to the negative lead of the generator.  If the field
is powered from the negative side there will be no current flow in
the field and the generator will not build up voltage. 
Now I guess I have to build the regulator from scratch.

Agreed over 7V is needed to fully charge the battery.  How does a
solid state regulator deal with output current limiting, if not a
heavy relay winding?  There is some carefully tuned feedback of
voltage and current in those old mechanical regs. 

I might be tempted to reconnect the gen field to make use of that
solid state reg.  Bruce Roe

[harvey b]

Ive had good luck with a regulator i got,it fits one of the old Ford 8N tractors,it is 6v pos ground,have had one on the car for near 10 years and still going strong,it is available at Napa still.i can get you the number if you are interested. Harveyb

[Cadillac Jack 82]

Car is working as it should.  The new regulator was the ticket.  Thanks everyone.

[Glen]

Agreed over 7V is needed to fully charge the battery.  How does a
solid state regulator deal with output current limiting, if not a
heavy relay winding?  There is some carefully tuned feedback of
voltage and current in those old mechanical regs. 

I might be tempted to reconnect the gen field to make use of that
solid state reg.  Bruce Roe

That is a good question.  The regulator on the Whitcomb uses a shunt resistor (for lack of a better name). It’s a coil of steel in the charging circuit, it has a 0.666 voltage drop across it at 20 Amps.  That’s enough to trigger a transistor. 
I had another thought; current limiting might be done with the output wire.  My 68 ELDO has a thick wire (6 gauge?) directly between the alternator output and the battery terminal.  The wire is actually part of the battery clamp.  What if the wire is calibrated to have sufficient voltage drop at high amps that it triggers the voltage regulator?  To put it another way at full amps the voltage drop on that wire is 14 volts.  The voltage regulator would see the voltage at the output and think the battery is charged.

If I did my math right that would make the wire ¼ ohms for a 60 amp alternator

[bcroe]

That is a good question.  The regulator on the Whitcomb uses a shunt resistor (for lack of a better name). It’s a coil of steel in the charging circuit, it has a 0.666 voltage drop across it at 20 Amps.  That’s enough to trigger a transistor. 
I had another thought; current limiting might be done with the output wire.  My 68 ELDO has a thick wire (6 gauge?) directly between the alternator output and the battery terminal.  The wire is actually part of the battery clamp.  What if the wire is calibrated to have sufficient voltage drop at high amps that it triggers the voltage regulator?  To put it another way at full amps the voltage drop on that wire is 14 volts.  The voltage regulator would see the voltage at the output and think the battery is charged.

If I did my math right that would make the wire ¼ ohms for a 60 amp alternator

The steel coil apparently is used for sensing the current, that is enough
voltage loss to drive a transistor.  Too bad it makes the solid state reg a
lot less efficient than the mechanical.  With the right OpAmp it could be
done with 1 percent of that loss. 

The resistance of a couple feet of 6 gauge is less than .001 ohms. 
We tried copper wire shunts at the beginning of my career, but the
variations with temp and end connections were intolerable. So 4 wire
(shunt) resistors became the rule, very small voltage drop and a
precision amplifier detector.  I read some early Toronados used wiring
loss to drive an ammeter, but not with much accuracy.  Bruce Roe