randyp Posted November 13, 2011 Share Posted November 13, 2011 Batteries were old and worn out on 86 r-model, sometimes it would start and sometimes not. It finally got to where i couldnt even boost it. i got tired of airing tanks up and pulling or parking on hills so went battery shopping. It has 2 six volt batteries on each side. Nobody round this dry isolated hell hole stocks 6 volts, they wanted to order them, werent sure when theyd get them, and price was more than 12 volts. Three,,,yes,,,Threee different truck mechanics told me i couldnt just put one 12 volt on each side, said not enough amps. Well,,,,bullshit,,,I put one 1000 cranking amp 12 volt battery on each side, eliminating extra battery cables to maintain in process, and sumbitch spins over like button on shit house door! We have already had 2 frosty mornings and it cranked both times, wasnt even daylight yet. I dont give a rats ass bout no silly ass 6 volt battery. Thas my 2 cents. Im also shamed 2 of those truck mechanics are "kin" to me. LOL randyp Quote Link to comment Share on other sites More sharing options...
Rob Posted November 13, 2011 Share Posted November 13, 2011 Battery technology has radically changed in the last 20 years or so. Although similar in size and function, a battery built today has much greater capacity and reserve than something produced years ago. Back in the 1970's a 750CCA storage battery for an automobile was available but rare, and needed routine service to yield a decent lifespan. Today's batteries with "sponge lead" technology used, absorb and hold a much deeper saturation level in the plates, and can be sealed not requiring routine service, (within reason). Shock absorbtion is another arena with significant improvement. Vibration is the second most destructive factor in a storage battery and todays units accept it much more readily than the formers. Heat is the greatest enemy of batteries.I run two 1100CCA batteries in everything diesel with the exception of the Cat powered RL, this one will still have three as the engine uses glow plugs for starting.Of course the analogy of "You get what you pay for" still applies. I've seen group 30, and 31 series batteries sale priced at $65.00, and double that. There is usually a reason behind the disparity.Rob 1 Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
MACKS Posted November 13, 2011 Share Posted November 13, 2011 Been doing that for years,running my 96 cl with two 12 volt instead of 4 12 volt and my 90 RD with just two 12 volt,so far so good but im sure they wont last as long as 4,also a lot of trucks running three 12 volts from the factory,seems to work good also. Quote Link to comment Share on other sites More sharing options...
umodelnut Posted November 13, 2011 Share Posted November 13, 2011 my u models only got two 12 volts and when its 30 degrees it will take a few turns but she will start right up. then there is a giant cloud of fog. :twothumbsup: Quote Link to comment Share on other sites More sharing options...
randyp Posted November 13, 2011 Author Share Posted November 13, 2011 Well i figured it would work, but kept getting advised it wouldnt. Im just glad im hardheaded,,,saved me a few bucks,,,,randyp Quote Link to comment Share on other sites More sharing options...
lobo Posted November 28, 2011 Share Posted November 28, 2011 My 71 Mack recently stopped charging. The 6 volts were getting old, one showing only 4 volts, dead cell. I put 2 12 volts in, starts fine, but still not charging. I am going to replace the generator with a new alternator. I would like to switch to neg. ground also. Will that toast my radio or anything else? Why are these lines in my post? Quote Link to comment Share on other sites More sharing options...
Mike Posted November 28, 2011 Share Posted November 28, 2011 My 71 Mack recently stopped charging. The 6 volts were getting old, one showing only 4 volts, dead cell. I put 2 12 volts in, starts fine, but still not charging. I am going to replace the generator with a new alternator. I would like to switch to neg. ground also. Will that toast my radio or anything else? Why are these lines in my post?Hey lobo,Where it said reply to this topic, you accidently touched the letters above the box where you started your sentence. If you look next time you reply to something, you will see a B I U S x x Just take the mouse and click off the letter or letters.mike Quote Link to comment Share on other sites More sharing options...
Freightrain Posted November 28, 2011 Share Posted November 28, 2011 Lobo, like Mike mentioned, you hit the "strike thru" box above your first sentence. This happened: hello, so you need to make sure you don't hit that box with the "S" in it. For your radio, you will likely need to just reverse the two wires. Red will go to 12v source and the black with be ground(body). Your AMP meter will need wires reversed on it also or it will read backwards. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
jaysm35a2 Posted November 28, 2011 Share Posted November 28, 2011 I did that on the B61 I bought in PA and drove to NC. The guy who hosed me on it told me its all great , etc. Then north of DC I shut it down for me and my wife and kids to eat dinner, Went to crank it , nothing. It took me walking 4 miles each way and trying to carry two 12v batts back to the truck , I took the old 4 6v's off , put the two 12v on and bam , cranked right up and never ever had an issue after that. Quote Link to comment Share on other sites More sharing options...
lobo Posted November 28, 2011 Share Posted November 28, 2011 Thanks guys, I did this gen. to alt. switch on a 72 R model we had once. I think it had a pos-neg switch on the radio. I think the new alternator will hook up with one wire straight to battery. Then I will have a field and armature wire from old generator going to voltage reg. I could just tape them up but amp meter may not work. Anybody here know what to do? Thanks again. Quote Link to comment Share on other sites More sharing options...
eddeere Posted November 29, 2011 Share Posted November 29, 2011 I run most of my antique tractors on 1 large 12 volt battery. They were 2 - 6 volt in series originally. Some where tne batterys are visable I still use 2 6 volt. Tractor Supply still stocks a good 6 or maybe an 8 vott at a reasonable price Quote Link to comment Share on other sites More sharing options...
Freightrain Posted November 30, 2011 Share Posted November 30, 2011 I just installed a voltmeter instead. Took a hot lead right off the key so it only worked with it on. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
lobo Posted November 30, 2011 Share Posted November 30, 2011 Thanks Freightrain, hot to volt or amp meter then to ground from 2nd terminal ( on back of meter ) or to neg. battery terminal? Quote Link to comment Share on other sites More sharing options...
lobo Posted December 4, 2011 Share Posted December 4, 2011 Well its charging with a rebuilt alternator. I bought from local Mack dealer bottom and top bracket for alternator. They had parts in stock and the same bolt hole pattern for bottom bracket on engine block. I changed top bracket also because the alternator uses a larger diameter bolt than does the old generator. I bought a rebuilt 160 amp alternator that is isolated, it does not ground through its housing. This type alternator has two wires, positive and negative. I hooked up these two wires to the starter and solinold pos. & neg. battery cable connections. I removed the voltage reg. and all of its wires. When engine started my original volt meter, I thought it was an amp meter, goes up to 14 volts. Also both 12 volt batteries are reading 14 volts with my hand held volt meter. The two 12 volt batteries turn the little 237 over just fine. I put one 12 volt on each side in middle of box and snugged down with original battery hold down for the two 6 volt batteries. My original battery cables hooked up to the two new 12 volt batteries. I did not change polarity yet, still pos. ground, but with this type of alternator I can change polarity anytime I want. Install looks orig. with no fabricating brackets and any stock alternator will slip right on. Brackets where not cheap, 125.00 for bottom and 26 .00 for top. A guy could go to a salvage yard for the brackets, I was in a hurry. I thought it was neat Mack did not change the bolt hole pattern on the block when they switched over to alternators. I always said working on a Mack was like working on an old Chevy. Parts interchange ability. If I get a chance will post pics of install and parts numbers of brackets. Thanks again. Quote Link to comment Share on other sites More sharing options...
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