Couple Of Wiring Clarifications 6V Related

[keithb7]

I am looking up under the dash at my ammeter, I see an assortment of wires on both connections of the ammeter. I am not 100% sure which circuit is connected to each pole. I will get in there and figure it out. Probably radio, heater, fog lights to name a few accessories, that someone added in the past 80 plus years. Just to confirm I want the battery feed on one post, all the rest of the electrical systems off of other other ammeter post? If there are too many connections I am thinking I will install a sub panel with fuses. Minimum 8 ga wire to the sub panel. I suspect as the previous owners added accessories , stacking more wires with eyelets it got too crammed on one ammeter pole. So people started adding them to the battery side of the ammeter?

 

Next question. My headlights are 6006 sealed type. Are these 35W low beam 45W high beam? Is my math right if I calculate:

35/6 = 5.83 amps per head light on low beam.

45/6 = 7.50 amps per head lamp on high beam

 

What are the most common old 5" inch or so yellow, sealed fog lamps, rated for wattage? 30W is a guess?

30/6 = 5 amps per fog lamp?

 

I checked my generator output with a digital clamp meter. I measured 16-17 amps (cold) when revved up.  So I surmise, running down the hi-way with hi-beams and fog lamps on, you'd be using up:

2 fog lamps 10 amps + 2 hi-beams 15 amps. For a total of 25 amps. Is that right?  A hot, warmed up generator puts out considerably more amps is my understanding. Is that correct?

Thanks, 

Keith

 

[Sam Buchanan]

I'm pretty sure a hot generator will produce less current due to increased resistance of the wire in the windings. So I think you will lose genny capacity as you add load and heat (electrical and ambient). Most likely you'll be running a current deficit with all the lights on especially at low rpm. It may take a while to pull a healthy battery down, but the lights won't be full bright....and the starter may be sluggish after the ice cream stop.

 

But fortunately there is a very nice remedy that will pull anything you can install on your car....and keep the battery happy.  ?

Edited June 2, 2020 by Sam Buchanan

[keithb7]

She's a fair weather town car. Daytime driver. Coming home in the dark is a novelty I don't get to enjoy very often. Fog would keep me home, yet I'll have good working fog lamps lol.  

Having the heater on is an early spring/fall occurrence. Then she's parked for the winter. My questions are more around curiosity and education, than real life episodes for my '38 Plymouth. 

 

Still having fun poking away at it here.

[maok]

Just a note, when you measured the output of the generator with your clamp meter, that would not have been the maximum output of the generator, just the amount the electrical circuit was drawing at the time, especially your battery charging requirement.

[keithb7]

Great point @maok!  Spot on. Electricity and all its little idiosyncrasies can be difficult to fully understand all the time. We can't see it, we must understand it based on principles. We can sure feel it though when we forget.

[keithb7]

Some Progress tonight on vintage working fog lamps. Now working.
 

 
 

 

[keithb7]

What period these little clamp-on-dash switches from?  I would guess later than the year of my car, ‘38. The fog lamp switch, plus it lights up too. 
 

I cleaned all connections with emery cloth. Sprayed contact cleaner in the switch. Worked it real good. All new wires from ammeter to switch, all the way to the lamps.I added new return ground wires too, back to a good clean ground point in the engine bay. All wire connections tinned, butt splices crimped, then soldered again. Then heat covered in heat shrink, Then anchored and wrapped in loom and tie straps.  Hopefully it’ll long outlast me. 
 

Old original switch is fused. All seems to work well, as it should. 
 

 

 

 

Edited June 2, 2020 by keithb7

[greg g]

My car will run fogs headlamps low or high, and the heater blower on low with no discharge at cruising speed. Good thing it's got vacuum wipers...Will show a discharge at idle when you throw in the brake lights.  But your battery if it is in good shape should give you a safe margin of reserve till you resume cruise. I think modern 6v sealed beams are 35 watts low, 55 watts highbeam.

 

Those switches were late 50s early 60s aftermarket deals.

Edited June 2, 2020 by greg g

[keithb7]

Thanks Greg. That confirms my suspicions on the dash switch.

 

PS. Those are not Harbour Freight stands!

[Sniper]

as for the wires attached tot eh ammeter, you are correct, one side is only attached to the battery, all the electrical loads and the generator should be connected to the other side.  The only thing the ammeter should be measuring is the flow into and out of the battery.

[greg g]

And keep in mind that the voltage regulators job is to replace electrical load flowing the battery.  So if properly functioning with a fully charged battery I. Good Nick, that replacement lever may or may not equal the load applied at any one time.  That's why you will notice the charge drops to near zero after driving down theroad for ten miles a after a start with no load but the ignition.  The VR replaces the current used to crank the starter, and when that's met, it goes into coast mode, showing no or very minimal charge as reflected by battery need.

[Ward Duffield]

Most of my 6 volt Mopars have shown a red-hot headlight switch in use, I suspect from internal resistance from the old, inaccessible contacts. A major improvement I have made is to control a 6V relay with the headlight switch, and run a new home run to feed the relay, out near the radiator, then feed the headlights from there, all connections and grounds clean, bright and tight.