Odd Charging Issue
 

I went through the old posts looking for some info on the charging system since after the alt swap I am still having some of the same issues. I replaced the alt with a 105A CS130 and now have a good charge mostly. At an idle with the lights on and the door open the lights flicker. Not off and on but dim to bright. The needle on the gauge bounces and when I step on the brakes the voltage drops to 11-12V. I have a window of a day and a half to figure this out and I hope someone here can help. I have move dthe relays in the engine compartment around and no change. The fusible link for the acc's was a huge wire that was wrapped in electrical tape and was badly oxidized. I haven't found any info on the link or how/what to use to make a new one. What should I look at next?:017:

ha! thats the exact same problem my car has had for the last 8 years, im still looking for it. my next step is to check my starter becasue ive seen them draw on vehicles b4 like this, but it prolly wont work. next im doing elimination testing, im gonna start disconnecting things and see which one is casuing the draw. basically what ive found is its an in cab ground problem, most likely in a component. i made a thread about it some time ago, prolly would have found it in the search. if you find anything, let me know!!!!! im looking too, and ive even gone to school for electrical diagnostics!

Does your needle jump when you hit bumps on the road. Mine does and that makes me wonder what is loose.

mine only bumps on big roads, needles kinda will do that a bit, but not major. hows the alt mount and belt tension?? its a weird problem that bound to be found one day, hard to do when i daily drive the thing. and the more i drive the more it gets to me, specially on rainy days when i need wipers, lights and the heater, i get down to 10.7 volts at idle, 12 while driving. no acc. i get 12 at idle, and 13.8 while driving.

Hum... Interesting problem you both have. I have not had that prob w/ my GM alt (puts out ~14.5v). I ran a 4 gauge wire from the alternator to the battery, and two 4 gauge ground wires (one to the body, one to the motor).

Shady... did you install a bigger alt to bat wire?

I get 14.5+ sometimes but it usually hangs in the 11-12 range. I changed the batt cables to 2 ga, the charge and body grounds to 4 ga and added the right connectors for the GM alt and still have the same problem. When you look at the prints for the charging circuit there's not much to it but all of the rest of the wiring kida complicates it. This one will take some time.

i used 4 guage to 120 amp breaker, and changed out the fuseable links to maxi fuses. the batt cables are 1ga.!!!!!! i really re-did the battery area circuitry, it helped gain .2 volts when i did it. wooweee. i got a bad ground somewhere, but cant rip it all apart while dd it. its part of a compenent failure, most likely, plus my fuel pump only runs after i start the car, makes it dang hard to start too, so im thinking realy probs too. gotta get the datsun truck on the road, then i can park the car until i redo some stuff. but b4 that happens, i gotta finish the 20x24 shop with hoist in my backyard!!

Holy shite batman! You have a lot going on these days. I'm seeing that the load really hits when I step on the brake pedal. That's when the volt gauge is showing the biggest drop. Hopefully it won't be a 12 hr weekend again and I can start checking that wiring to see what I can find. Mine is a dd too adn it definately makes it hard to get anything done. I like the change to Max Fuses I need to look into that.:038:

yeah the brake pedal does the biggest on mine too, sucks when your idling at night really bad, in the rain!!! i checked my system loads, with everything on im drawing 85 amps, no wonder i went thru 3 nissan 60 amp alternators. the chevy keeps up, but it still aint right. now i have extra electrical goodies, like a dual fan, and high flow pump, better headlights, bigger stereo, and msd 6a box and coil (big draw there)

Saw a place online that was advertising up to 265A Gm style alts. Maybe that's your next step. LOL...

the old alt tested fine but I know it's a dud. The one night I was heading home it dropped off the gauge and the car barely ran. I stopped for some food and when I left the restaurant the volts jumped up to 14 and stayed there as long as I didn't slow down. I bet their load test is at a high RPM and low amp so the alt would never show bad.

your going thru the saga i went thru. the one wire may have broken off at the alternator that keeps the feild charged. there is a wire at the back that goes from the stud to the white plug. take a peek, dont bother with the nissan alternator, get the gm one.

Is that the wire that has a piece that looks like a capacitor? That was hooked to the "E" terminal on the old alt and not the Batt terminal. That could definitely be an issue. I'll change that puppy tonight and see what diff it makes.

yeah, i just used a piece of wire instead of the thingy, its only to help with interferance, didnt notice a diff with noise.

ok i found something and its leading to progress. i found that there is a major voltage draw at the acessory relay behind the glove box. its the closest one towards you when you sit in the seat. unplug it for me and see if the problem gets better, mine did now i have to trace that and find the voltage drop. i changed out the relay with a spare, but no dice. i ttok the fuses out of the acc. spots and no dice, but when i unplugged the relay, i could turn my headlights on and the voltage stayed at 14 at idle, my car has never done that!!! can someone do a voltage drop test at their fuses in the acc system?? pre 80's s130.

I installed an MSD coil and have had static only with the radio ever since.

I also installed a GM alt and it charges like a mother! :038: The only issue I see is that the idle is too low to excite the field. If I give it a touch of gas it'll crank the needle up and it stays there. I am still going to look at the relay though, just to make sure.

my idle is the same, but it wont fling the needle up with acc. on only with no load. unless i unplug that relay, then the headlights can be on and the car at idle with 14 volts!! all from unplugging that one relay. but no acc then.

so i took my car to a electrical specialty shop and had them test to see how much draw my car is pulling out of the battery when everything is turned on. guess what, my car uses 113 amps when its all on (and running). that is way way too much. is there anyone with access to a inductive amp meter that can test there car for me???? i know my msd draws lots and my electric fans draw near 30 amps, but jeez i got a problem somewhere. this shop is also building me an alternator that can charge 100-110 amps at idle!!! so that part will be fixed, but i still wanna reduce some of the load to save hp. heck i dont even have an amp or sub hooked up yet till i figure this thing out.

Shady, so, what exactly do you have "on" when you're at idle?

I can't imagine any way a relatively stock electrical system could be drawing that many amps, especially when your alternator is probably a 60 or at most an 80 amp unless you've upgraded it to a 100amp GM 1 wire or equivalent.

im at the gm 3 wire (idiot light and guage) 100 amp max alt right now, next is the 100 amp idle unit. when at idle i have "on"
my lights (upgraded)
my wipers,
my brake lights,
my radar detector
my heater
my dual 12" electric fans
my msd 6a box
my rear window defrost
my radio (no amp or sub)
upgraded fuel pump
and the stuff to make the car run (stock otherwise mentioned)

it is an insane amount of power being draw, ive chased tons of things around and re-wired the links and alternator lead to 4 guage. ive done voltage drop testing and cant really get a good amount of work done as the car is my dd. the fans alone draw 25 amps running, and msd is said to have near 25-30 as well. so right there is 50 extra the car never had.

do you know if a rear window defroster would stop working if it was getting enough volts but not enough amps?

anything will stop working with no amps. volts are the horse power (pushing amps) amps are the torque that does the work.

I am having a charging issue. To much. with everything on-15 volts. everything off. 18+. at idle. this just started yesterday. and is not the first time. I fixed it before by replacing the Alt. but only 1 year on this one. and i got it new. I'm thinkin volt reg. but why would they keep going out. i leave my headlights on till the car is off so i don't fry nothing at 18+ volts. The car has always ran at 13-15 volts. alt type-oem replacment. I am also having an issue with tail/break lights. seems to only come arounf when the ail fcks up. press the breaks, the tail light(bi**hing betty) coes on. after you release, it goes away. and the break lights out light also comes on, and don't go away till i turn the car off and then back on. i've checked em out. all tail lights and break lights work fine.

Deep Cycles are the best. The alt is not even charging the battery, hince 18 volts. it's not powering the engine either. the heater got slower. and slower. the engine started poping and grunting. and right as i pulled into the driveway. i noticed the heater was barely running. the engine was barely running. i turn the heater off. the engine got better. turned heater back on. the engine died. The alternator is powering the lights. and defrost. but not the heater and engine. so for two days. the battery has lasted.

hmmm thats very odd. yeah i got a yellow top optima they are very nice, and not so spendy any more. the 18 volt thing happened once to me when the batt fuse got blown, and all the power ran straight to the fuse panel. it blew my intermitant wiper amplifier. i have since re-wired and put maxi fuses and a 120 amp breaker and 4 guage wire from the alt directly to the batt. then all the stuff comes off the batt, not the alt. much better way of wiring it. nissan didnt really think that part thru.

i found a loose terminal. but that did not work. this thing is het wire. what fuse was that? cause unless the engine actuly fires up. none of the inter stuff will work. volt meter reads 0. no lights nothin.