PCM Voltage Control

    First off I know I have a problem and I tend to research and read a ton of stuff when upgrading guns, boat, or the sling. Sometimes to the point of creating a problem with over doing it and making things more complicated than they should be.... I have a yellow top now and I am adding 4x 6.5" speakers and 2x 6" JL audio subs that will run on a 2k marine amp. I also have what I consider a standard led light setup (brows, halo, under, wheel, some inside). That said, I've been debating on the alternator upgrade + wiring to support. I really don't think I need this though with my setup and have had it in the cart numerous times and never pulled the trigger as my plan is to see how this works and if lights dim, then add if I need to.


    Flash forward to this morning and I stumbled across some info on a PCM voltage control module. The conversation started when someone asked why the cobalt alternator was identical and put out 90 more amps than as configured in the sling. While I think some of this has to do with the pulley size on that alternator... Another guy was saying it has to do with the PCM settings on the sling and it's set to output around 13v. He also posted this link to a product that would correct that with the stock alternator - http://www.usalternators.com/g…AdULMu9YB4EMQAX1x_UY_0kPE That said I messaged him for more info and although this is not plug and play it can be wired into the factory harness or they might be a converter (still figuring that out). Anyone done this? As I understand it with the fixed version it would change the output to 14.8v (+/- .02) - which my yellow top would be incredibly happy with as compared to only getting 13v. I would think even though using stock alternator you'd want to change the grounds and power wire?


    Before I order one of these - I'm curious if any of you have done this and what your experience was!

    Should of been working on the sling today, but dang if buddies wife didn't have plans for him today... So honey do list and some more reading. Found this option as well - https://customelectricservice.…xtGr1O3sYFMtjRmUnwEIdQbFs


    So thinking some 1/0 wire from alt to frame, then the +/- with the same gauge wire to the battery. Since I don't need more amps and really want more volts from the alternator - this seems like a good way to go. I read a bunch of cobalt forums today with alternator posts and it varies but most are 13.8-14.5v reported output compared to most sling folks saying stock is 13- to 13.5? This makes me think the PCM is just set on these to limit the alternator more and I need to open it up a bit..


    Kyle D any thoughts? I see you guys have a cable that goes between the PCM/alt for older GM's that was 4pin and added .6v output

    Quote from 3GunSteve

    Should of been working on the sling today, but dang if buddies wife didn't have plans for him today... So honey do list and some more reading. Found this option as well - https://customelectricservice.…xtGr1O3sYFMtjRmUnwEIdQbFs


    So thinking some 1/0 wire from alt to frame, then the +/- with the same gauge wire to the battery. Since I don't need more amps and really want more volts from the alternator - this seems like a good way to go. I read a bunch of cobalt forums today with alternator posts and it varies but most are 13.8-14.5v reported output compared to most sling folks saying stock is 13- to 13.5? This makes me think the PCM is just set on these to limit the alternator more and I need to open it up a bit..


    Kyle D any thoughts? I see you guys have a cable that goes between the PCM/alt for older GM's that was 4pin and added .6v output

    The alternator on the slingshot is intended to be pcm controlled. Since polaris left that wire off for whatever reason, the alt defaults to just over 13v. If that controller creates and send it's own signal to the alt, then it should work.

    ZZPerformance EST 2000 - Go Fast Not Broke

    Kyle D Thank You - that makes sense.


    I did some more research and here's where I'm at. After emailing and then talking to folks at Custom Electric - their box according to them costs a lot less to manufacture (not made in USA) however functions the same as the dial version from USAlternators. I also messaged another sling owner who has it installed and his feedback in this image.



    That said this is the one I ordered and shipped free for $79 - GM/Slingshot Voltage Controller w/ Battery Light Delete – Custom Electric Service

    I went with the below from Amazon for $135 shipped and a good chunk of that was the crimper/cutter that I didn't have for wire this size. I will be able to use on my new boat batteries so saw it as something I should have anyway. CCA or copper clad aluminum was cheaper, but like with the stereo I'm a believer that oxygen free copper is the way to go so doing the same here.



    So we'll see how it works out after the other projects done. Going to try to measure output before/after to confirm. If it does work at $79 for controller and knowing you should do wiring upgraded when you upgrade alternator anyway, I think this makes sense. More to come...

    Question for you guys and couldn't find it in the alternator swap threads. For those of you that swapped your alternator and did the "big 3" wiring upgrade. What did you do with the fusable 40amp blue wire that runs from alternator to starter? In stock configuration this is providing all the charge/power right? Thank You BKL for sharing the thread where rabtech upgraded his to 6 gauge with 60amp inline, but did anyone leave and just add wire to battery? This link is here for a reason so reading how some leave it and some remove it in tons of big 3 wiring upgrade discussions this morning and I'm confused now lol. My thought is if it's left in place and you run wire from alt to battery, then doesn't that defeat the purpose of having that link? or does this allow for more amps to flow directly to the battery (yellow top in my case) which can handle it?

    I haven't done the alternator/wiring upgrades, but it's generally a good practice to use a fuse or fusible link with any high current cable and mounting it as close to the power source as possible. Adding a special circuit for an amp generally calls for adding a fuse close to the battery (the power source) and Polaris mounts a fuse package near the rear-mounted battery on the Gen 1 Slingshots (2019 and earlier). Skipping the fuse or fusible link on a long wiring run means you have a lot of potentially heat-generating cable to possibly cause a fire if it overheats and the fuse or fusible link near the start of the circuit adds extra protection. In my mind, better safe than sorry.

    Edited once, last by BKL ().

    If you need more power for your stereo amplifiers you will have to add a stronger alternator and a heavier wire between the alternator and starter terminal. But when you do make sure you add a fuse in between. Like yall mentioned above its a fusable link that your swapping out. The link between the starter and battery is good enough to carry the higher amp alternator amperage back to the battery.


    My stereo would actually kill the engine when the bass hit hard. The alternator would make the engine just shut off. . When I was done adding the 200amp alternator and the heavier jumper wire it doesnt even notice the bass hit unless they are really rapid. And even then it just drops a couple hundred RPM. Remember the battery doesn't really make that much difference when your talking about stereo power. Once the car is running it sucks the power from the Alternator. I didnt mean the battery was not completely unimportant. You need a good battery and great connections.

    Quote from Kyle D

    The alternator on the slingshot is intended to be pcm controlled. Since polaris left that wire off for whatever reason, the alt defaults to just over 13v. If that controller creates and send it's own signal to the alt, then it should work.

    That is why i never see the Alternator make 14 to 14.5 volts like most do when the battery is in a weaker state. I have wondered why it never made more than around 13 volts.

    Good to know. I was expecting it to be like my truck and ramp the voltage up to 14 or 14.5 right after the vehicle starts and then slowly drop down to around 13. I believe the most I have seen is 13.7 volts on my AEM display.

    Quote from rabtech

    That is why i never see the Alternator make 14 to 14.5 volts like most do when the battery is in a weaker state. I have wondered why it never made more than around 13 volts.

    Good to know. I was expecting it to be like my truck and ramp the voltage up to 14 or 14.5 right after the vehicle starts and then slowly drop down to around 13. I believe the most I have seen is 13.7 volts on my AEM display.

    This is why I think folks have success with the big amp alternators as I'm not seeing where they are PCM controlled. I can't tell for sure on JS one, but this one specifies no plug and mentions how it self excites. I'm not 100%, but to me that's not PCM controlled then -https://www.universalaudiosolu…et_Alternator_Kit_.html#/


    It's going to be a few weeks as that controller is coming USPS and still is enroute...but this is what I'm planning on. PCM controller on stock alt. I'm doing the two 1/0 grounds (battery and bock) and then running the positive 1/0 from alternator post to battery. I'll put that wire on alt first, then blue fuasable feeding starter on top and off that same + alternator post. On the battery end of the 1/0 - going with inline ANL fuse holder and then got fuses from 40-120amp.


    Knowing electricity is going to go least resistance, my system will still get fed and I'll have a direct line to my battery. My thought is that 40a fusable is really feeding current draw for the sling and what's left goes to battery although I'm pretty sure there isn't much charging going on now. Some articles that I found that helped me learn more about this and what voltage is needed to charge batts. Plan is to do a before and after reading as well so I see what I have. Stock configuration and wiring, at alternator and then at battery to see line loss. Then same test with PCM controller and the upgraded 1/0 wires ran to see what the difference really is. Just don't want a fire in the process!


    DIY with diodes - http://www.smartgauge.co.uk/alt_mod.html

    Good article on charge voltage - https://www.matec-conferences.…cconf_aigev2017_01076.pdf

    Optima charging info page - https://www.optimabatteries.co…tegories/support/charging

    Optima article on batt voltage - https://www.optimabatteries.co…heck-your-battery-voltage!

    My 1/0 inline fuse holder showed up...Damn this sucker is huge! I know I know...teed it up for ya'll... - I got mini ANL fuses though, so sending these back as I need full size ones. Other things to work on anyway while I wait for the right fuses :)


    Quote from 3GunSteve

    My 1/0 inline fuse holder showed up...Damn this sucker is huge! I know I know...teed it up for ya'll... - I got mini ANL fuses though, so sending these back as I need full size ones. Other things to work on anyway while I wait for the right fuses :)


    Tripod liked this 30 minutes ago and has yet to respond...? "sucker is huge" "ANL"


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