brickhouse15 Posted April 4, 2018 Share Posted April 4, 2018 Good afternoon, Is it worth it to switch from a generator to an alternator on a 1962 B-61? If so, what's a good alternator that can replace my current generator? I have limited knowledge about electrical systems. I have read that Mack used a positive ground? Can someone explain what that means and what's involved with converting to a standard ground? Thanks! Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/ Share on other sites More sharing options...
eddeere Posted April 5, 2018 Share Posted April 5, 2018 (edited) A one wire alternator works . A good starter, generator, alternator repair shop will give you the size once they know the battery size and what you are doing . Just switch the wires on the fuel gauge, amp or battery gauge, and heater fan switch . I used my old generator bracket and some all thread to get the correct alignment on the belts . If your old generator works and you are concerned a good shop can rebuild it . Most older system are pos. ground which means the battery is grounded to the frame on the + side of the battery. Negative ground the - side of the battery is connected to the frame. Edited April 5, 2018 by eddeere add more 1 Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-395965 Share on other sites More sharing options...
h67st Posted April 5, 2018 Share Posted April 5, 2018 (edited) An alternator is definitely more reliable; if you go to a one-wire unit like eddeere says, you can eliminate your voltage regulator...lots of people do that on older cars & trucks. Your lights work the same whether positive or negative; you don't have to change anything on those. If your truck has a series/parallel switch, I don't know what has to be done to change to negative ground. Edited April 5, 2018 by h67st Forgot to add something Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-395970 Share on other sites More sharing options...
Freightrain Posted April 5, 2018 Share Posted April 5, 2018 (edited) Just had to replace the one wire alt on my truck after 15 yrs(it was starting to not charge all the time). Kinda pricey, but is 160 amp version. More power then I need for a all mechanical truck. I'm thinking like $200? Have to dig up receipt to confirm. I got it at local starter shop. You can re use the stock generator bracket, just had to make spacers to locate the alternator between the original tabs on the mount. Long bolts or some all thread and nuts. It lined up perfectly with crank pulley. Had to revamp the slide bracket for adjustment as it was not correct to match up with alternator slot. Not a big deal. Then just one good, like #6 wire, run back to the batteries(bigger the better) and one good ground from alt to frame. I replaced my AMP meter with volt meter. You will need to change your battery connections to NEGATIVE ground. The starter will still work fine(the series/parallel switch should be fine too since you are just changing polarity). If you keep the AMP meter, you will need to pull dash and swap the wires around since it will read backwards with the change of polarity. I put a 12v starter in mine the same time I swap to alternator. My s/p switch was giving me fits and I was tired of messing with it. I don't recall swapping wires on gas gauge or heater motor. The heater motor should be shaded pole, meaning it only runs one way no matter what direction you put power to it. I could be wrong. I was once before...... Edited April 5, 2018 by Freightrain 1 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-395975 Share on other sites More sharing options...
brickhouse15 Posted April 5, 2018 Author Share Posted April 5, 2018 My truck is air start...and after reading these responses, it seems like I can just keep the generator for the time being. I really appreciate the help guys! Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-395984 Share on other sites More sharing options...
Freightrain Posted April 6, 2018 Share Posted April 6, 2018 1 hour ago, brickhouse15 said: My truck is air start...and after reading these responses, it seems like I can just keep the generator for the time being. I really appreciate the help guys! Air start! Yes. Lol. You don't have all the starter wiring to deal with(multiple batteries). I still left both my 12v batteries even though I put air start on last winter. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-395996 Share on other sites More sharing options...
Hobert62 Posted April 7, 2018 Share Posted April 7, 2018 Amp for amp. What's the diffrence between an automotive alternator and a truck one? Is the truck one just made heavier for the long term use? Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396072 Share on other sites More sharing options...
eddeere Posted April 7, 2018 Share Posted April 7, 2018 Just a question . On my truck when I pull the heater knob out the fan starts at a high speed . The farther out I pull the knob the slower the fan gets. Not that it makes a difference . Would switching the wires change this . Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396104 Share on other sites More sharing options...
Freightrain Posted April 8, 2018 Share Posted April 8, 2018 The heater fan switch has a resister built in and that is how the switch functions. Off, hi, lo. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396121 Share on other sites More sharing options...
h67st Posted April 8, 2018 Share Posted April 8, 2018 On 4/5/2018 at 7:59 PM, Rob said: You can use a standard GM 10SI series alternator which is not "one wire". All the one wire means is the electrical connection(s) point is internal to the case. The standard 10SI series has the external plug. Looking at the rear of the alternator and the field winding plug/terminals on the top, connect the right terminal to the "Bat" terminal. It is now electrically the same as the "one wire variety but you've now done it externally at about 1/3 the cost. You can leave the left terminal open, or environmentally seal it. Photos are on my 62 B-67ST and it works like a charm. You will be best to purchase a wider sheave which is about $10.00 for an "A", or "B" industrial drive belt(s) as automotive vee belts are an in between size and the Mack belts will work but ride high in the sheave groove. Where does the left terminal wire connect to on your truck? Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396129 Share on other sites More sharing options...
glitchwrks Posted April 8, 2018 Share Posted April 8, 2018 On a 10SI, #1 terminal (the one that doesn't go to battery positive) can go to an idiot light on the dash. IIRC if you have the light hooked up, it'll start charging at lower RPMs but I may be remembering incorrectly. You wire from switched positive (accessory, ignition, etc.), through an indicator lamp, to the #1 terminal, if you want the idiot light -- personally I always hooked them up, even though I almost always had an amp or volt meter in the dash, since it'll come on as soon as the alternator stops putting out power. Just another warning mechanism! #2 terminal, the one that most people connect right to battery positive on the stud on the back of the alternator, is for charge sensing. IIRC the official answer is that it's supposed to run back to the actual positive terminal on the battery, so that the alternator's regulator can detect voltage drop and vary its output accordingly. Almost everyone connects it to battery positive right at the stud on the back of the alternator, which is fine most of the time. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396136 Share on other sites More sharing options...
glitchwrks Posted April 8, 2018 Share Posted April 8, 2018 Yeah, I've seen plenty of 10SIs wired up just like yours, and they run fine for many years. We use them on pretty much everything on the farm, once the original alternator dies -- big trucks, the older Ford tractor, air compressor, welder, generators, etc. Apparently they're even a drop-in for Volkswagen/Bosch alternators on old VW diesels, as long as you don't need the tach output! Just thought I'd offer my understanding of what/why the other two terminals exist Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396157 Share on other sites More sharing options...
Freightrain Posted April 9, 2018 Share Posted April 9, 2018 I just replaced mine because it took forever for it to kick on. I'd have to drive it for 5-10 minutes before it would suddenly start to charge. When I took it to have it checked, the guy came back and said "Yup, it's got problems. It needs to see 3500 rpm to charge". Ya, that's a problem(with a motor that on goes to 2100 rpm). New one kicks off instantly and hopefully keep up with the load. That was the other issue, with all the lights on, it would hardly keep 12v. With air start it is not really a problem, but still not good. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396258 Share on other sites More sharing options...
Phase 1 Posted April 9, 2018 Share Posted April 9, 2018 On 4/7/2018 at 3:03 PM, eddeere said: Just a question . On my truck when I pull the heater knob out the fan starts at a high speed . The farther out I pull the knob the slower the fan gets. Not that it makes a difference . Would switching the wires change this . On 4/7/2018 at 6:08 PM, Rob said: It shouldn't. The switch is in a series configuration in the blower motor circuit. You are adding resistance when you change motor speed and the switch itself is dissipating the additional current through heating of the resistance of the switch. Don't matter which end is in, or out. Basically you are cutting the voltage back that reaches the blower motor as the switch slows it down. Correct me if I'm wrong, but I believe that is done on multi position motor controlling switches to aid the motor. It is better for the durability of the motor to start at full power. Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396260 Share on other sites More sharing options...
Freightrain Posted April 10, 2018 Share Posted April 10, 2018 I limped it along for a few summers. It always got me there/back so I wasn't too concerned. Not like it needs power to run once its started. With two batteries, my lights would survive a few hours without it which covers most of my trips. I am glad I finally changed it though. Had issues with my '69 F100 years back. It too would not really keep up if the electric fan kicked on(motor cooling). Thought it was strange and finally pulled the alt and took it back to Azone. They confirmed the regulator was bad(likely one side of diode pack toasted). I apparently had gotten the "gold" one and it was lifetime warranty. They handed me a new one and wow...it charges like crazy even with the fans on. Unlike the wagon, unloaded it in Pittsburgh last fall and made it to the staging lanes and suddenly no charging. Ugh. Had to get a ride back over to Turnpike to get to an Azone and replace it. Using the Mack was going to be a real PITA due to pit parking was packed and no real place to go once I got in. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396312 Share on other sites More sharing options...
Freightrain Posted April 10, 2018 Share Posted April 10, 2018 The alt on the Mack is not an Azone unit. It is a truck unit from local shop. Yes, the other ones were from Azone. I know they don't have "quality" stuff, but I can't say it has caused me any real grief. Having Azone stuff on the wagon is good, cause I can get parts anyplace I go. I have friends that buy the high end special stuff(starters/alt) and if they have issues at the track,,,,they are screwed. When I plumbed the air intake on the new motor I used 4" steel exhaust tubing from Summit Racing. I didn't have alum welding capabilities back then. I do now. Try Summit racing. They list alum tubing, straights, turns. Summitracing.com Link to what I found: https://www.summitracing.com/search/product-line/vibrant-performance-aluminum-tubing?SortBy=Default&SortOrder=Ascending&tw=aluminum tub&sw=Vibrant Performance Aluminum Tubing I ordered silicone couplers from a place online. They have anything you could need. http://www.hps-siliconehoses.com/hps-silicone-coupler-coupling-hose.html Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396326 Share on other sites More sharing options...
1965 Posted April 10, 2018 Share Posted April 10, 2018 I’ve had very good luck with the duralast stuff from autozone. There battery’s 2. Way better than NAPA Quote Link to comment https://www.bigmacktrucks.com/topic/53015-generator-to-alternator/#findComment-396328 Share on other sites More sharing options...
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