Bob - a charging system question??

[DanEC]

Thanks Bob and Patrick - at least 5 watts then. I suspected I wouild need something a lot heavier than Radio Shack stocks. I'll give John a call this week and order one of your 20 ohm resisters. Can't remember if I cecked continuity on the fuse last Spring either - plan to do that today first.

[patrickt]

Originally Posted by DanEC

Thanks Bob and Patrick - at least 5 watts then. I suspected I wouild need something a lot heavier than Radio Shack stocks. I'll give John a call this week and order one of your 20 ohm resisters. Can't remember if I cecked continuity on the fuse last Spring either - plan to do that today first.

You know, with electronic voltage regulators Ford used a 500 ohm resistor in parallel around the warning light. It was only on the older style stuff that they used a 15 ohm resistor in parallel. A lot of our OEM looking voltage regulators are really the newer style on the inside, but look old on the outside. I don't know whether you are new or old on the inside. But, if you surf the Ford forums, you'll see some people saying 500 or 560 ohms and some saying 15 ohms, and they have their Ford/Autolite documentation in front of them as they write it, and that's the reason. Plus, a lot of people don't use any resistor at all, or don't know whether they have anything in there to begin with. I suppose, in theory, you would want to use the highest ohm parallel circuit around the light that resulted in proper excitation of the VR.

EDIT: An authoritative cite: http://workshop-manuals.com/ford/exp...nd_inspection/

[DanEC]

500 ohms - I figured that must be the size of can of soup. But according to this apparently not.

500 Ohm 10W Resistor Wire Wound 5% Tolerance | 016-500

I originally started with an all electronic VR that I believe came from ERA. When my charging issue popped up - and not exactly being a fan of solid state regulators, ignition systems, etc in old cars - I bought a mechanical VR and installed it. Neither one ever worked - so far. Alternator bench tested OK and puts out good voltage in testing. I still have the mechanical VR in it since I like being able to look at something mechanical like points and understand what is going on.

[patrickt]

Originally Posted by DanEC

500 ohms - I figured that must be the size of can of soup. But according to this apparently not.

As resistance goes up, wattage goes down. So, at the same 12.6v, a 500 ohm resistor will create less than half a watt and draw virtually no current (less than .03 amps). I think we need to send you back to school.

[DanEC]

Originally Posted by patrickt

As resistance goes up, wattage goes down. So, at the same 12.6v, a 500 ohm resistor will create less than half a watt and draw virtually no current (less than .03 amps). I think we need to send you back to school.

If I haven't said lately that I hate electricity - let me address that omission. Electrical stuff equals All I know about electricity is don't stick a hairpin in an electrical outlet - light bulbs are right hand threaded - and volts x amps = watts (which actually does address the above to some extent). I much more prefer working with levers, cams, gears, points, bearings, seals, latches, etc.