12 Volt conversion by Dick Cashion:
When Converting the 6 volt system, All parts necessary to keep it in A I condition are available from your corner auto supply Store, at the larger auto flea markets, or from other club members. A good enhancement to the 6 volt system is a Sears Commercial Die Hard group 4 battery, available only through the catalog. This larger battery, which requires a modified hold-down, works well in step-downs. There may be clearance problems in earlier models, so measure before you buy. This battery, number 9694, measures 7 x 12 and is 8 high plus terminals).
A change to 12 volts, while not a necessity, does have advantages. Electrical system components (generator, regulator, coil and bulbs) are universally available; the starter turns the engine over much more rapidly; there is less chance of a fire In the electrical system because a 12 volt system requires one-half the amperage of a 6 volt system. In addition, 12 volt accessories such as a tape player, cruise control, electronic Ignition.’ or air conditioning can be installed without the expense of modification to 6 volts or the use of a 6 volt to 12 volt converter (from my own experience, a suitable converter is not only, expensive but is difficult to locate because of Its size and ventilation requirements; it also introduces a distracting buzz in audio equipment).
These advantages must be weighed against the cost of the conversion and the possible disadvantage of strain on the 6 volt starter, If retained. Otherwise, the conversion introduces no additional problems.
The Alteriiator/Generator - . There are two ways to go, one simple and the other more complex. The simple approach is to install a 12 volt Hash or Chrysler product generator in place of the present 6 volt unit. This is a bolt in as no modification should be necessary except for a 12 volt regulator. The Hudson pulley and belt are retained. Installation of a 12 volt alternator is more difficult since a new bracket must be fabricated.
I used a 12 volt Delcotron generator. The hudson pulley, without the use of the 1/8 inch shaft shim, fits the Delcotron shaft perfectly. I used two mounting brackets. The first was fabricated from x 2 inch angle iron stock, It bolts to the existing bracket holes in the block to provide a surface to which to bolt the second bracket (a standard 6 cylinder GM Delcotron mounting bracket as used on a mid-GO’s Chevrolet). A template for the fabricated bracket will be provided in a future issue of this newsletter. The Delcotron I used is a 10 SI series which has an internal regulator. Celcotron generators which require a separate regulator (like the existing Hudson 6 volt system) are also available. In either case, you want to use the pre-1980 small Delcotron (referred to as a 51 inch unit); later Delcotrans are too large. The small generators are available rebuilt or from a salvage yard.
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12 VOLT CONVERSION
Since I used my existing fan belt (a Dayco 24405), the Delcotron installation was rather tight. I have a 3/8 inch clearance between the Delcotron and the water pump (a longer belt would provide ware clearance). The adjustment bracket is relocated from the stud at the lower side of the water pump to the bolt at the top of the pump; a inch spacer (two flat washers) is used where the bracket attaches to the Delcotron. Because of the tight fit, the belt had to be installed on the pulley before the mounting bolts for the Delcotron bracket were installed.
Battery - I used a side terminal, 60 .month battery with the terminals facing the Delcotron. Be sure to purchase a battery with the negative terminal in the forward position. The positive terminal Is connected to the starter solenoid, as the conversion also changes the polarity of the electrical system from positive to negative ground. The battery I used takes a group 24 holdCdown. Sears has an inexpensive kit that works just fine.
- A very simple, two wire system is used: The BAT terminal on the Delcotron case is connected either-to the positive terminal on the battery (using a pigtail common to most battery cables), or to the same terminal on the solenoid that the positive battery terminal is attached to. The Ho. 2 terminal of the internal regulator is connected (jumped) to the BAT terminal on the case. The No. 1 terminal of the regulator is connected to the wire presently attached to the Hudson regulator for the teleflash signal in the instrument cluster (refer to your present system wiring diagram). The internal regulator will not work If the dash light does not function (it needs the resistance of the bulb). Since the Delcotron regulator is energized (turned on) by the current from the bulb circuit, it would be a simple matter to wire a failsafe resistance wire or bulb under the hood to prevent a no-charge situation,
The main service wire currently attached to the BAT terminal of the Hudson regulator is reconnected to the battery side of the solenoid (positive terminal). The Hudson regulator can be discarded.
Ignition - No changes are necessary to the points or condenser, but a 12 volt coil is necessary (or a lower voltage coil with a dropping resistor). Since the polarity of the system has been reversed, the wire from the ignition switch must be attached to the positive terminal on the coil (through the dropping resistor if one is used) and :he wire from the coil to the distributor condenser to the negative terminal.
Starter No changes are necessary. However, it is suggested that the starter not be used for prolonged cranking periods as It will be prone to overheat operating or’ 12 volts, if his concerns you, a 12 volt Hash starter could be used or the field coils of the 6 volt starter rewired In series.
Lights Obviously, all 6 volt bulbs must be replaced with 12 volt bulbs. The 6 volt headlight relay I installed years ago works fine on 12 volts.
Horns - I retained the 6 volt horns; they are much louder on 12 volts. Since they are only occasionally used, I do not expect a problem. fl is not necessary to change the horn relay.
Directional Signals - A 12 volt flasher is required. You ray have a problem replacing the indicator light to the left of the instrument cluster as it is very difficult to reach and space is tight. The bulb socket plugs into the back of the jewel retainer like an instrument light. However, if the retainer disconnects itself from the jewel bezel $ you will have a very difficult time re attaching it (it is spring loaded and the jewel bezel must be inserted in a slot in the retainer). I got the job done by holding the retainer (less bulb socket) with a small, needle nose vice grip plyers).
Fuel and Temp Gauqe - On 51 to 54 Hudsons, these gauges are powered by a regulator providing a constant 8 volts. This regulator has an upward Input voltage tolerance of 8 volts. Based on my experience, and the experience of others, the gauges still appear to work correctly (although faster) at 12 volts, so no modifications Should be necessary. I suspect that these gauges do not draw much current. if you prefer a safety margin, you could use a dropping resistor similar to the one mentioned earlier for the coil, but for a much lower wattage. Unregulated pre-51 systems may also require such a device. If used, I would suggest that it be mounted under the hood to avoid a possible heat problem.
Clock The Hudson electric clock has a mainspring activated, jeweled movement which is wound every few minutes by means of an electrically activated solenoid. Current is supplied to the solenoid through a set of points controlled by the clock movement. The 6 volt coil used in the solenoid can handle 12 volts with no problem, so no change Is necessary. The clock will operate at 12 volts in the normal manner. The only difference is that the solenoid will wind the mainspring faster (not more frequently). The auto clock expert I consulted said not to worry. If the clock stops, it will be for other reasons. If your clock is currently in need of repair, it can be converted to 12 volts by changing the coil, but this is not really necessary.
Radio The Hudson tube radio, unlike a transistor radio, will operate correctly in either a positive or negative ground system I had mine converted to 12 volts by a WTN advertiser (works better than new). The conversion charge was $25 in addition to the normal rebuilding charge. This is the best way to go. Alternatively, dropping resistors or a converter must be used to power the 6 volt radio in a 12 volt system.
Heater Van - The heater fan turns much faster on 12 .volts than on 6. I am running mine on 12 volts and have had no problem It is more effective). If you are concerned, you could adapt a 12 volt motor obtained from a salvage yard.
Conclusion - In my opinion, the conversion was well worth the effort. Not only is it now much easier to obtain electrical svstem components. but the engine now starts much more rapidly (especially when hot) and Janet and are now enjoying our favorite cassette tapes without the distracting buzz we had with the converter. In addition, I’m flow ill set to install an electronic ignition., which requires a 12 volt system. If I encounter any problems, I’ll te sure to let you know what they are and possible solutions.