Bradshaw

hey guys. so i've got a 94 vx with a brand spankin new duralast gold battery. i was cleaning out my tahoe the other day and found my cig lighter voltage gauge. i know its not super accurate for getting voltage loss from a system hitting hard but its nice to know since there isn't a gauge in the dash.

plugged it in and i've been noticing that under 50mph, it seems like nothing is charging. it sits at 12.5v. as soon as i pass 50mph it shoots up to 14.3v and stays there until i go back under 50. i feel like if the alternator was bad, it just wouldn't charge at all. none of this on and off nonsense. is this just a thing the vx models have in an effort to save gas in city driving? or should i look into a new alternator sooner than later?

i'm sure its the original alternator. i also have a 2nd batter in it (been tested as well and its good. only 1 year old) and an RD 1750.1 amp pushing a 12" SA12. i don't really bast it too often honestly so i doubt there is any voltage drop. only reason i threw an extra batter in the back is because i only had 4 gauge and that wouldn't be enough to power my amp unless it was right next to the 2nd battery. which it is. and the 4 gauge to the front is only to charge the 2nd battery. alternator isn't gonna even put out enough charge to need more than 4 ga. will all be upgraded eventually.

for those who don't want to read:
do vx models have a special system that only lets the alternator charge above 50mph?

seems really dumb to me. probably just gonna check out some of dc powers alt's since i really like the only in my tahoe.

Bradshaw

should have done a bit more searching before posting, but i found something about ELD (Electrical Load Detector)

this thread

https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/alternator-connector-pinout-alt-cutout-switch-2977344/

sounds like what happening. seems extremely pointless to me. i mean REALLY how much load can an alternator charging at 12.5 vs 14.2 be? doesn't that mess up circuts and ohm readings?? i guess it makes it calculations based on what the current voltage is at? oh well i guess i got my answer lol

Former User

The ELD system is a fuel saving feature.

Bradshaw

i understand that. i just don't know how much fuel that could possibly be saving. and at the expense of wearing out a battery faster?

regardless, i'm looking into one of these guys in the near future. i'll look into disabling it then as well.

Former User

Depends on your use of electrical accessories. If you drive at night primarily (lights on), then there would be little benefit. If you drive a lot without any accessories on, then gas mileage would be noticeably improved. The idea is that every little bit helps.

What gives you this false impression? That would only happen if you rewired your system such that some electrical accessories bypass detection by the ELD.

The ELD does not prevent charging blow 50 mph. The ELD measures electrical load and maintains 12.5V alternator output only if the load is low, regardless of vehicle speed.

Bradshaw

gotcha, thanks for the explanation for some reason i thought the alternator just shut off. makes more sense now that its charging, but only at 12.5 volts. i just figured out as well if i want it to run at 14 volts i can just turn the parking lights on or something. looked into the bypass stuff and it seemed pretty complicated so i'm just gonna leave it alone lol

KeithsDAteg

Just run all the time with your parking light on if it bothers you. Wouldn't that cause the ELD to be disabled?

Bradshaw

yeah thats what i was saying. if i'm turning up my music or doing some testing or just have a need for 14v i'll just turn the parking lights on. i confirmed earlier today that the parking lights will put it at 14v

Bradshaw

i know i started this thread a little earlier, but two weeks ago i was having the strangest things going on. my voltage was at 15v and went up to almost 17 at some points in time. this happened for a week straight. i figured that the voltage regulator on my alternator was done for. i disconnected my power wire for my head unit and amp (only aftermarket connections to battery) and it was back to normal.

craziest thing about it was i had crazy good gas mileage that whole week i was having high voltage charging. my usual is about 42-45 mpg. my avg that week was 55mpg. i haven't connected them back in 2 weeks since then but my last 2 fill ups were both back to normal at the mid 40's for mpgs.

i know my ignition timing needs some adjustment so maybe the higher voltage did something with that or maybe i was getting better spark. who knows.

just thought i'd put this bit of information here.

Former User

How are the radio and amp wired into your car?

Bradshaw

well the reason i have a wire from the battery to the head unit is because i wasn't getting any power from the constant 12v power in the back of the headunit. it was also all hacked up before i even got to it. it was cut off already so i taped it off and ran a new wire/fuse from the head unit to the battery. every other wire works perfect. 12v switched, ground, and speakers.

been wired like this for months and never had a problem. just went back tonight and hooked it back up. we'll see what happens tomorrow when i head to work.

Former User

Wiring directly to the battery bypasses the ELD, but this would not cause the alternator to put out excess voltage. I think the alternator is probably toast.

Bradshaw

possibly. but its been working perfectly since then. going between 12.5 and 14v. i had it tested and they said the alternator charged but the voltage regulator was done. we'll see i just want to get a few more pay checks before i buy a new one. ideally a nice high amp DC power like i have in my tahoe since i have some plans for a big system in the future.

any idea how to disable the ELD? or wire through it so when i turn my system up it goes to 14v? gonna do some searching.

Former User

Yeah, a bad voltage regulator is consistent with the high voltage output. If you don't replace the alternator, you risk destroying the battery and it exploding.

There's a way to disable the ELD, but it will throw CEL code 20.

The ELD does not prevent the alternator from increasing the system voltage when needed. When the electrical load is high, the ELD will not prevent high voltage output.

Bradshaw

well i found myself here. seems they've done some research.
http://forum.sounddomain.com/ubbthre...page/0/fpart/3
no matter what a new alternator will be in the works soon.