Alternator conversion on 61 LeSabre

[seeholmes]

Hi All,

 

Im going to put a PowerGEN alternator on my 1961 LeSabre. The Arm wire from the VR to the Generator looks to be 8 or 10 gauge (Does anyone know for sure??) I was considering using this line to power the alternator. My other option is to just run an 8 gauge line down to the starter. If anyone has done this swap or knows the Arm wire gauge size I would love to hear.

 

Thanks..

 

Craig

[Bill Stoneberg]

Do not use that wire. when you order the power gen, order the correct wire also.  You will find that you will need a relay that comes with the powergen.  you can use your existing wiring for that.  Don't forget these put out 75 to  90 amps.  Your 60 year old wiring was not meant for that.

Edited August 16, 2019 by Bill Stoneberg (see edit history)

[NTX5467]

Might be good to try to keep the new alternator's output range closer to what the OEM generator put out.  Granted, some of the alternators will put out much more than what the generator did, but only when demanded to do so.  Just like a 50KV ignition coil is capable of that kind of output, but only if it's needed.  It doesn't put out that amount of KV if the engine is idling, for example, but is capable of that output if the need for it arises.

 

Just some thoughts,

NTX5467

[seeholmes]

On 8/16/2019 at 6:18 PM, NTX5467 said:

Might be good to try to keep the new alternator's output range closer to what the OEM generator put out.  Granted, some of the alternators will put out much more than what the generator did, but only when demanded to do so.  Just like a 50KV ignition coil is capable of that kind of output, but only if it's needed.  It doesn't put out that amount of KV if the engine is idling, for example, but is capable of that output if the need for it arises.

 

Just some thoughts,

NTX5467

Thanks for the replies guys. I ended up finding the wire gauge in the service manual. Its 10 gauge and about 7 ft of wire. At 90 amps with a voltage drop tolerance of 5% this gauge wire is ok. The above point on alternator output is very relevant. This was my thought as well. I haven’t increased my load above factory (i.e. stereo, etc) as it stands i measure 14.5 volts at the battery under moderate load (headlights on)

 

all the factory wiring looks the same as i internally jumpered an old voltage regulator which connects the ARM and BAT terminals. This gives me a straight shot from the alternator to the battery. Next, i snipped the gen light wire off of ARM and connected it to FIELD terminal. This terminal was isolated internally so its really just a dumb connector on the outside. 
 

I wouldn’t take this approach if the factory wiring us dodgey and or if your running all sorts of aftermarket stuff. In a stock case with good wiring i say its a good clean option.

 

[NTX5467]

When the cars were newer, about the highest-draw use would have been police/law enforcement use.  The additional lights and their tube-type radios.  ALL of which usually operated for extended periods of time.  Many times with generators of about 60amp output or possibly a bit more.  With the earlier "generator" cars, they probably had some sort of manual "fast idle" mechanism as the generator output at base idle was not too good . . . something which the later alternators greatly helped.

 

At the OEM "normal" level of things, we didn't see OEM 100amp alternators until about the later '70s, to power the electric rear window heater grids.  Usually with the same wiring harness wire gauges as had been used for years prior, by observation.  At a time when the factory a/c cars had something like 62amp alternators.

 

Unlike in modern times when a 130+amp alternator is the norm.  With larger batteries as factory equipment, too!  All to help power the on-board computer systems, hvac functions, communications/infotainment items, etc.  Things were much simpler when all that was needed was a 42amp alternator!

 

Just some thoughts,

NTX5467