12V Conversion but I want to keep the 6V Overdrive Controls

[ALBUQ F-1]

Nope, everything is straight resistive load, just like a light bulb.

[alanco]

Originally Posted by Julies Cool F1

Well here we are again with Alan and his drilling holes in batteries - not only dangerous but un necessary and creates a number of other problems. People stopped doing that (most people) in the 50s.

And congratulations on your math...yes 10 amps at 12 volts is 120 watts. But a 6 volt solenoid drawing 10 amps is only requiring 60 watts Where is the 6V at 10A coming from? A device requires so many watts of energy to pull in against the spring tension. If you operate it on 6V, it will use twice the amperage or 20A to get the power to 120W. . The device is rated for 12 amps at 6 volts or 72 watts output. Hmmm I don't see the problem. So if the device is rated at 72 Watts and not 120W, then it would draw 12A at 6V and its resistance would be .5 ohms. So if you wanted to drop the voltage to it on pull in, it would have to be a .5 ohm resistor with a 72W rating. Try finding that. Then to compound the problem, when the pull in is done, the pull in coil is switched internally in the solenoid and the holding coil is about 20W or 3.3A or a resistance of 1.8 ohms at a 20W rating. What happens if you use a .5 ohm resistor and the solenoid switches to hold in? Try 10.35 volts. How long is that holding coil going to last with that voltage on it?

But Alan is right in two respects - first a Vol-ta-drop is limited in its use, is inefficient because it converts excess voltage to heat, and really shouldn't be used. That is of course why folks regularly install them, the high end restoration shops use them, and they have been working reliably for 60 years Which is a facetious highly qualified statement, For-one thing, most shops use electronic voltage reducers for gauges. I build my own with pc board and zener diodes. but what do they know. And I might ask, what do you know? You do not seem to be knowledgeable about any type of electronic or electrical convention in trucking shops. 24V is common on large trucks and Army Vehicles and conversion via taps and electronic inverters is commonly done. And the other incredible idea of tapping a battery in its mid cell of course is the best solution, I have never claimed that it is the best or the most elegant solution. I am claiming that it is the least expensive solution that will operate properly. that's why every battery manufacturer in the US and Canada produces and sells a battery that has a mid post in it for converted vehicles - like not even one. Technological evolution and safety experience be damned, those people don't know what they are talking about. Because we are talking about 54 year old vehicles and 6V is no longer used, it is no surprise that batteries are no longer made with taps for 6V, but they were. What you do not realize is that a volt-a-drop has to be made for the average current draw of the wiper motor because it runs at two speeds. Another has to be made for the heater motor average draw because it draws different amperages and different speeds. The voltage dropped will be too low at low wiper or low heater and too high at high wiper or high heater speeds. A volt-a-drop is ok for a radio. A volt-a drop can be made for a gauge, but the gauge also draws changing current, so it will not be accurate for it either. When a vehicle has three gauges, all of which work by changing current, how accurate will the volt-a-drop be in dropping exactly 6 V? These problems are engineering problems and if given to an engineer he would not recommend a resistor solution, for obvious reasons. I would also not want 4 volt-a-drops under a crowded dash. It is also not dangerous to tap a battery. But in place of a tap, you could use a 12V to 6V inverter rated at 200W and this would run everything correctly. I am currently using Wipers converted to 12V, Heater converted to 12V, gauges running off my homebuilt zener diode electronic 12V/6Vconverter, and I don't have an OD. If I did have an OD, I would simply use a 12V solenoid, and use a small resistor soldered to the OD relay coil. If you have solenoids and you do not know what they are just try them with a battery charger set at 6V. If they are 12V solenoids, they won't pull in. Same as you might test horns with.

Alan, read the post. I have already had the installation completed and working with the vol-ta-drop. I put thousands of miles on the 55 truck with a 12 volt electrical system, 6 volt overdrive, and a vol-ta-drop. It did work, it does work, and it will work. It's safe and precludes the Jerry rigged situation that a drilled battery presents. That kind of garbage is just BAD work. And trying to convince others those "slip shod" methods are better is just irritating. Your method is wrong and it works only because your OD hold in coil is being used at too high of a voltage. Being defensive and calling sound engineering principles slipshod is the voice of a jury rigger. (Not jerry rigger) I not only do not agree with you, I do not like your bullying. If you doubt what I am saying, take the problem to an engineer. You know that you are wrong.

For Ross, I guess you could measure the resistance. I'm trying to figure what that is going to tell you though. I'm not quite sure I'm following you though on measuring at the "terminals"....Those solenoids should have two wires coming from them. I would think that if you were trying to ascertain if they were 6 or 12 volt, you would "pop" them using a 6 volt battery and measure the amperage draw on each. The six volt solenoid should work and the 12 volt solenoid should chatter.

In short, tapping or using an inverter or using two 6V batteries is the engineered way to go, but I would, due to the ease in changing the wiper motor and heater motor to 12V, and the simplicity in using electronic voltage reducers for the gauges, and just using a 12V solenoid with a 12V OD relay, to go that way. I managed to buy a 12V wiper motor for $35 by using classifieds on this forum, E-Bay, and HAMB, and finding a 6V wiper system in the first place. (My cab did not have wipers.) My heater came from a 56, so it was already 12V, but only the motor needs to be changed, and you can get a new heater motor for $40. I recently sold a 12V OD solenoid and relay and wiring and kickdown seitch for $120 through this forum. The 12V relay was new. Looking in classifieds like Craigs List, E-Bay, this forum and HAMB will turn up a lot of parts at good prices.

Regards,

Alan

PS. I am a graduate EE from University of Nevada. I am also a NASE Certified mechanic and I do computer automobiles with fuel injection. I have closed my shop except for friends and my own stuff.

Here are two formulae for figuring out electrical problems:
E=IR and by simple conversion, E/R=I and E/I=R E=voltage, I=current (Amps), and R=resistance in Ohms.
P=E X I (Power in watts= voltage times Current (amps)

[Julies Cool F1]

Originally Posted by alanco

PS. I am a graduate EE from University of Nevada. I am also a NASE Certified mechanic

Well Alan, that's pretty impressive.

And after reading your responses above, well, I guss those who choose to believe you and your "sound engineering principles" can.

Alan - you're an idiot - really! I've never experienced anyone with your philosophies who didn't come out of "the hills" and maintained a mechanical philosophy so backward (not even ameturish but just plain messed up- in all respects) as to try and convince others that they were "sound mechanical pratices." Torro Guano!

As someone whos credentials [which really are not appicable here - yours or mine] far excede those, I simply don't understand why someone with your education can't seem to contribute more responsible inputs- from a simply technoligical standpoint. Seems that credtials don't build trucks.

As a matter of fact my experience has shown that credentials don't reflect intellengence or a thought provess either. Knowledge, experience and an intelligent grasp of fundamentals, coupled with the ability to analytically rationalize solutions to problems is the key.

A smart person with a high school education is a smart person. A moron with an advanced college degree is a moron - it happens - sorry.

And Alan, only people with big educations and little intelligence try to post their certifications on web sites to justify really bad or unqualified inputs.

If I might suggest, I'd be much more subtle.

[alanco]

Julie:
Your method or denigrating someone who does not agree with you is what my concern is. Your method is to insult my person, and my solution and attempt to make fun of me. That is simply bullying.

You made inaccurate sweeping statements in your assertion that all restoration shops use vol ta drops and anyone using a 6V tap is an idiot. Well that is a nasty mean bullying statement that is incorrect. Many shops would just buy the gauge conversions at about $100 a gauge, or would put in a new gauge panel. It also depends on whether the panel has one or three gauges. Most 55s do not have 3 gauges and do not have an ammeter or oil pressure gauge. A simple electronic voltage reducer is the easy solution. However I would never use your solution for an overdrive solenoid. That you got a vol ta drop to work shows a great jury rig. If you got a resistance high enough above .5ohms like 1 ohm which would drop 8V so the solenoid would still pull in at 4V then the overvoltage to your hold in coil is reduced ti 7.7V which obviously has not burnt it out. But no one can say that this is an elegant solution, but it does work

For you to accuse me of not knowing my math, or using engineering skills in building cars and trucks I used my certifications, because if I did not have them many people would not have used my services, particularly with the NASE. If you don't have knowledge and common sense you won't pass the NASE test. I am proud of both certifications because they were a lot of work and study. They helped me immensely in my approach to building on a budget and doing it correctly. None of my trucks has ever broken down on the road, and only one of my cars. I learned not to use nylon line for an add-on oil pressure gauge.

I know that you think that I threaten you and you are defensive and defiant, but nothing is gained by your bullying and arrogance. You give everyone a lot of help with basic electrical problems, and you are very active in this forum. I do not pretend to have the time to devote in the forum. I only post on things that are legitimate questions that I know the answers to. But I can figure out the tough electrical questions that you can't, In short, in a instance like this, I could have helped you out, unless the fellow wants to jury rig his OD. Ce la vie.

Regards,

Alan.