Alternator Doesnt Charge Battery Until I Blip the Gas

[vegita319]

So after getting a new alternator and redoing the lower wiring harness, the alternator doesnt charge my battery until I blip the gas pedal. My voltage will be at around 11.9 - 12.1 or so. As soon as I blip the throttle, it jumps up to 13.8-14.2 where it should be.

After talking to a bunch of people, they say that my voltage regulator is not getting a signal and thus when I blip it, it bypasses the signal and charges the system anyways. This is the reason why I redid my lower harness. I checked for continuity on all my wires and they all check out ok. I also sanded down the connectors and cleaned out the pins and plugs.

Now I'm stumped. Maybe I'm not looking at the right places. I printed out the wiring diagram for the charging system and everything checks outl.

Anyone know anything about charging systems that can offer me some input on other locations to check? Maybe its some other place besides the voltage regulator.

P.S. All the fuses are good and the car does drive once i blip the gas. It's just the initial startup. I read somewhere that the alternator might need the engine idle to be at a cerrtain rpm before it charges the system. I turned up the Idle and nothing, still the same thing.

[SilviaSky32 S13]

is your car battery relocated to the trunk? i had this problem

[the head]

could be you have a bad voltage regulator...your system is responding like a self exciting (one wire alternator) system where the charge is RPM based not current draw based...have you tried a different alternator?

[vegita319]

Originally Posted by the head

could be you have a bad voltage regulator...your system is responding like a self exciting (one wire alternator) system where the charge is RPM based not current draw based...have you tried a different alternator?

I just got my alternator rebuilt, and one of the things he replaced was the voltage regulator. So I have no freaking clue. I know our cars our internally regulated unlike the older datsun and other american cars. To answer your question though, no, I have not tried a different alternator besides rebuilding it. It's hard to source an alternator for the sr but I have heard you can use a KA and swap the pulleys over though.

To SilviaSky32 S13, my battery is in the factory location.

Also, my belt keeps squeaking. I've replaced the belt already and on top of that found the best belt dresser I could (dont remember the name). It still squeaks. Everytime I tighten the belt some more, it will stay quiet for a week or so, then will squeak again. I'm thinking it could be caused by my pulleys, but not sure. I doubt this is related since my alternator problem still persists whether the belt squeaks or not.

Thanks for the response so far guys.

[shayrgob240]

did the guy test the alternator after he rebuild it? I had my RB alty rebuilt and my probs persisted so I think you should look into getting another alternator.

[vegita319]

Yeah, I even brought in the alternator again to test it to see if it was the alternator acting up. The problem still persists.

[shayrgob240]

are u checking voltage at the battery or at the alternator? Check both and let us know what readings you get. Maybe there's excessive resistance in the wiring between the alterntor and the battery.

[vegita319]

My readings are at the battery. So I'll get readings of before alternator charges at the alternator and at the battery; doing the same after blipping the gas as well. But the thing is, the alternator is hooked up to the battery as well. So how would i check the volatege of the alternator without the battery influencing the signal? This is just going off the top of my head when i looked at the wiring diagram, troubleshooting this thing.

P.S. Thanks for the quick response shayrgob240!

[theicecreamdan]

do you have a lot of load on the electrical system?
How is the condition of your battery? it might be reluctant to be charged and that extra current from being at a higher RPM is enough to push it over a threshold.

what is your car idling at? I forget which types. but there are alternators that don't charge well at idle, but are quite efficient above idle and at higher RPM.

[the head]

Originally Posted by theicecreamdan

do you have a lot of load on the electrical system?
How is the condition of your battery? it might be reluctant to be charged and that extra current from being at a higher RPM is enough to push it over a threshold.

what is your car idling at? I forget which types. but there are alternators that don't charge well at idle, but are quite efficient above idle and at higher RPM.

Most self exciting alternators are like this car charges above 1200 or 1500 but below alt puts out little voltage

are you by chance running and underdrive pully?

[JohnC]

I had the same problem.
I had my alt rebuilt after I started overcharging to
16v. After the rebuild no more overcharging but starting
the car would cause the same symptom as you described.
Had it rechecked and all but two moths later alt went bad again
and started overchrging again so I just bought a new one
for my SR and that was it.

[redsuns3838]

everything is dim in my car until i blip the gas after start up. , guage, headlights, etc. im almost sure it has to do with my lower-wiring harness, because its a total hackjob. (dont even ask) did you redo your lower harness yourself? you might want to double check everything on it.

[GSXRJJordan]

I know this seems backwards as hell, but I'd put up a tank of gas that it's your battery ~

A bad battery actually puts a static load on the electrical system, and causes the squeaking and the low voltage. I have a small race battery in the front (that's so close to dead it's not even funny), and a huge ass brand new battery in the trunk, wired as a single load. When it's cold out, I get the squeaking belt too, but as soon as I disconnect the race battery, squeaking goes away and voltages jump from low 12s, to mid 13s.

You have to remember that unless you disconnect the battery, the reading you get from the terminal OR from the alternator is the same reading: voltage from alternator minus static load from your probaby bad battery.

[Creizai]

Did we ever figure this out lol my Ka24e just started doing this oh well least i got my backup car now

[ledzeppelin240]

-The voltage regulator is controlld by the ECM.
-You have to put a load on the system to correctly test the alternator.
-Check voltage drops as well as chaging voltage.
-A battery is the ultimate voltage regulator, if it does not need anymore voltage it will not take the voltage.
-How many amps does the alternator put out at 2000rpm under load?
-Make sure the belt is tight and not slipping.
-Place a screw driver at the back center bushing and it should be magnetic, which means the following:Voltage regulator, Brushes and Rotor in the alternator are all working
-A Delta wound stator is the type of alternator that puts out high amps under higher rpm's.