1990 RW E9 Starter & Alternator Upgrade

[davelakeside1]

Alternator not charging 12V side or 24V side. Leece Neville Alternator and Transformer are weak. Can find an alternator but the Transformer, last one in the world , is $485. My thinking is to get a new 12V Leece Neville or Delco 160A or 200A Alternator delete the Transformer and swap out the 24V Starter to a Delco 39MT 12V 11Tooth 7.3KV Gear Reduction Starter #8200308.Now the fun starts.     Questions:                                                                                                                                                                                                                    1- The max Amp input to this starter is 2500 CCA. Should I just use the two 12V 1000 CCA Batts for everything, or keep all four 12V 1000 CCA Batteries, Two for starting and two for everything else just not connected together? Similar to what is currently in use today        12V side and 24V side?                                                                                                                                                                                                                                                                                                                                                                                                                                            2- How would all this get wired together? I couldn't find anything in BMT that gave me some specific directions to do this. I can use the existing 12V wiring from the alternator to the rewired batteries from 24V to 12V Starter circuit. I can use the 24V wire from the                 Transformer and connect that to the 12V Alternator Terminal and run it over to the everything else batteries  but I don't know how they will get regulated?                                                                                                                                                                                                       3- I don't have a clue how to use or remove the S/P or otherwise bypass it. Do I need to add a solenoid on the firewall for the starter or just hook up the battery cables and use the existing start wire to the starter. The Delco starter has a mag switch that feeds the starter      solenoid.

I have a fair bit of electrical/mechanical knowledge but there is too much money involved when working on something like this. Don't want to let the smoke out!  Any help would be greatly appreciated, especially if there was some sort of wiring diagram  to follow, even if it was a hand sketch.  Any help would be greatly appreciated!

 

 

 

 

[Back In Black Pulling]

Just have to take off the cross over cable and wire both sides to starter( 2 pos and 2 Neg) and wire stater the as it is now as far as the ing wire 

can disregard the 24 volt charging wire or put on the 12 v alternator your choice should work like that

don't have to run new wire to cab on right side they will all be connected on starter

Edited May 20, 2020 by Back In Black Pulling

[davelakeside1]

Back in Black Pulling : Thanks for the reply! The room started to spin thinking of what needed to be done with the S/P Mag and any other solenoid on the firewall.

[Vladislav]

In fact you should end up with what a typical 12V starting truck has. Just put 12V starter and organize batt cables to be supplied with 12V from the batteries. If you already have 4 batts connect them the way Back in Black described (I would do that). If you currently have 2 batteries left them alone and isolate or remove the cables to the other side (where you had 2 other batts for 24V) and you will be fine in the most cases to start maybe excepting really cold temps. In fact more batteries with more capacity is more chances for easy start.

The alternator you put its 12V straight to charge 12V connected batts and forget about transformer and other things. Also connect the rest of truck electric to the setup as long as it's 12V and you have 12V at starting/charging.

There could be another way of keeping 24V starter in place with 12V alternator and no transformer if you add series/parallel switch as it was done on earlier trucks such as B-models etc. But seems much better to use 12V starter if such option for a E9 is avalible.

[davelakeside1]

Thanks for the reply's!  As usual, nothing is ever simple!   My current thinking, subject to review, is to put in a battery Isolator. ASE / Eaton has a 240Amp Isolator  that will charge both battery banks individually as required. Each bank will consist of two 12V 1000CCA batteries. One bank for 12V starting only, and one bank for 12V everything else. As far as the alternator goes, it'd like to use a Leece Neville 12V 200A Duvac with a sense line to keep the batteries in tip top charge. The problem is the old E9 100A alternator was self exciting so I need to supply the Isolator with a 12V IGN source to get the alternator charging right up. Just need to find a 12V source off the key. The other issue is the E9 only has a single pulley off the fan to drive the alternator. Even though the pulley's and belt are heavy duty with the wide belt, I don't know if they will hold up/not slip when used with the 200Amp alternator under a heavy charging load after a start up, especially a cold weather start up. If anyone has any input on this I would greatly appreciate it. If the 200Amp is too much, I'll have to drop down to a 160A, which is the Mack recommended Delco Remy replacement alternator for the old E9. I only have one shot at this alternator decision, can't afford to buy two.

I found a 12V starter. It's a Delco Remy 39MT w/Gear reduction. It has an onboard solenoid and a mag switch. Only issue is that this starter should only see 2500CCA on a normal start. Now, in cold weather after few tries the two 1000CCA Starting Batteries will drain down enough so I can safely jump start with the two 12V LH side run batteries or another truck. I'm thinking I should replace the battery cables with 4/0 while I'm at it as they are getting old and dried out. Have to get a 12V solenoid that connects between the key switch and the mag switch on the starter, according to the Delco installation instructions. Except for the starter, everything is just on paper, so making changes now is real easy and cheap. Not having done this before really ups the level of concern, don't want to fry up something, so any help/suggestions/corrections would be greatly appreciated!

[kscarbel2]

For the E9, I strongly suggest that you retained the 24-volt starting system. There's a very good reason why Mack engineering chose a 24-volt starting system. Switching to 12-volt would be a downgrade.

[1965]

Don’t understand why you wouldn’t hook the 12volt batteries together. 

Don’t  understand why you need such big amp alt.

you can get single wire alt. 1 belt should be sufficient if not running something like water pump 2.

Can’t beat a 24volt crank when it’s working. Keeping them maintained is the key.

[Back In Black Pulling]

Switched mine to 12v spins it just fine . If i remember right think it is 48 mt 

 

Edited June 11, 2020 by Back In Black Pulling

[davelakeside1]

Thanks for the reply's! The 24V Starter is not the problem, works just fine.When everything is right, just touch the key and it starts with a roar! The issue is keeping the 24V starting batteries charged. The alternator is getting weaker by the day. Have to charge the batteries every other day. The 12V-24V Transformer- Rectifier isn't putting out much over 16V. Found a 12V-24V Transformer- Rectifier on line for $465. Outrageous because they haven't made any for almost 20 years! So it all boiled down to simple economics, especially when a fellow on this list said he basically had to replace  the transformer almost every 4 to 5 years. Mine has been running more than that, but is getting very tired. I bought the 12V Delco Starter new for $225, The alternator will be around $250-$300 and the Battery Isolator will be about $125. So for $600 plus another $100 for all new cables it's all fixed up and charging correctly. If I went with the alternator that would match the 12V-24V Transformer that would be $350 plus the transformer for$465, plus the $100 for new cables that would be $915 and would still have a time bomb transformer that it it did go out, there isn't another one available to replace it, so i'd be stuck and probable have to swap over to the 12V starter set up then. It would be like throwing good money after bad. As far as the 200 amp alternator goes, it's not much more than the 160Amp but it would be loafing along and woul hopefully last longer. The 12V electrical load on the truck is approx. 130A with everything on max, so the original 100A alternator has been working overtime on several occasions. The 12V starter that I bought is a Delco Remy 39MT with a gear reduction and 11 teeth. The RPM is almost the same as the 24V and with the gear reduction it has almost the same HP. I know, almost only counts in Horseshoes and Hand Grenades, but it will be good for 10 months out of the year, and plug it in during the winter. I have to plug the 24v system in overnight anyway so it really isn't that much different. I am far, far, from being anywhere near a know it all, and know even less about these Superliners. I'm simply trying to explain what my thought process is, and what I'm thinking of doing, and relying on the years of good practacle experience you guys have to steer me in the right direction! Thanks so much!

[1965]

Guess I should’ve worded differently, how come the battery isolator?

[davelakeside1]

Sorry, I didn't catch that. The purpose of the battery Isolator is to be able to separately charge each battery bank as needed. There are two 12V batteries on each side of truck that came standard on the E9's. RH side batteries were  connected in series  to provide 24V for the starter, These two were charged by 24V Transformer approximately at the rate of 10A so they would be charged up in 15 to 30 minutes. The two 12V batteries on the LH side of the truck were hooked up in Parallel to provide 12V power to everything on the truck except starting. These two batteries were charged directly from the alternator. So, in effect the two battery banks served two different purposes, were totally separate, and were charged separately. I thought that this was a good design by Mack and wanted to maintain the two separate battery banks. This is where the plan to do this presented a few problems. I tried to find a battery step up transformer that would charge the 24V side in similar fashion as the original transformer. Couldn't find one that would handle the load. I didn't want to simply hook up all four batteries together in parallel to give 12V to everything because the Delco 12V starter didn't want to see anything more than 2500CCA. All four batteries hooked up in parallel would produce 4000CCA's. I thought that this many amps start after start would severely shorten the starter life. I tried to find a battery separator that would work but that didn't pan out because it wanted to connect all four batteries together after the start side batteries voltage dropped 3Volts. This much current would severely shorten the separator life. It. took a while but I finally found a battery Isolator that would keep both battery banks separate and would charge each bank separately, and was rated for 240A, it's cost was only a few dollars more than the Separator, all solid state, no contacts to arc over so I thought that this solved the problem. On paper and in theory  this should work. I also need to add a 12V IGN source to excite the alternator because the original alternator was self excited, and a couple of Circuit Breakers to keep everything  safe and prevent anything from burning up. Please let me know if this answers your question. I'm trying to provide enough information on what I'm trying to do here, so as these trucks get older and parts are no longer available, this could be a solution. When all this is installed, and hopefully working, I'll list out the parts, and part numbers that I used so anyone could do this if they chose to.

[1965]

Seems like a plan.

I know if it were me (I’m not saying I’m right at all), if I was going to make it 12volt, I’d hook all them together & I wouldn’t even worry about the amps going to starter. I know this is not really the same but I put a bigger amp alt. on a truck before because of winch, and it would over charge batteries because not enough draw during regular usage, & I know regulator shouldn’t allow but did. 

[davelakeside1]

Point well taken. I can easily drop from a 200A to 160A alternator, and save some money. My only thought for going with the 200A was that this is an around town truck. Lots of starts and stops and hours of sitting not running with flashers, beacons and warning lights on for hours at a time. I was just thinking that the 200A would charge the batteries up quickly. Now, if it was an over the road truck that was driven for hours at a time I wouldn't hesitate to go with a 160A alternator. The other point in the thinking was that the total Amp Draw on the system is approx. 130A so that only gives me 30A head space. Is that enough? I don't know.