Help! Changed battery and alternator - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Eternal_240Sx · 04-24-2004, 10:37 PM

Hi, i have recently swapped a s13 redtop into my s14. Right after i took the car out of the shop after getting it wired. My car dies out of the freeway. I tow it back to my house and check the battery, the battery was dead so i got a new one. Then just to make sure i also checked the alternator, it wasnt charging so i figured that it was the alternator, now i just put a new one on and it still does not charge the battery. What could it be???

FastBack 240 · 04-24-2004, 11:10 PM

Check and make sure you have a strong enough ground. If your grond is shitty then you wont hold a charge.

Eternal_240Sx · 04-25-2004, 01:50 PM

how do i know if its strong enought ground or not. I think there is one pluge and 2 other wires to it. The 2 wires are ground?

DS 240R · 04-25-2004, 02:19 PM

Either get a Consult, nProbe, Techtom or voltmeter to check the voltage. You may have a problem with your ground or with your voltage regulator.

When you said "new" alternator, did you get a brand new one or a "remanufactured" one from an auto parts store.

I went through three "new" alternators on my car before I just fixed the voltage regulator on a reman'ed OEM one. In my experience, 2 out of 3 auto part store alternators are bad or fail right away.

Eternal_240Sx · 04-25-2004, 07:30 PM

hmm.. im sorry its not a new one, its actually a used one from my friend who also has a redtop. His was working when he took it off and eventually gave it to me.

DS 240R · 04-25-2004, 07:53 PM

Well, I'd check your idle voltage then. Techtom or nProbe is the easiest, it should be around 13.5 volts, plus or minus a little. You can also use a voltmeter- just ground the one and put the positive on the positive terminal on the alternator.

When my alternator was going bad, it was around 11 or low 12.x volt range. Make sure the car is running when you check

Usually the alternator coil is fine and just the voltage regulator is toast. I know on the B13 and B14 SR20 the VR is integral into alternator, so you have to take it apart to replace. I'm not sure about the JDM DET alternator- I know it is different, but probably the same design.

04-24-2004, 10:37 PM	#1
Eternal_240Sx Zilvia Addict Join Date: Dec 2002 Location: norcal, bay area Age: 41 Posts: 674 Trader Rating: (1) Feedback Score: 1 reviews	Help! Changed battery and alternator Hi, i have recently swapped a s13 redtop into my s14. Right after i took the car out of the shop after getting it wired. My car dies out of the freeway. I tow it back to my house and check the battery, the battery was dead so i got a new one. Then just to make sure i also checked the alternator, it wasnt charging so i figured that it was the alternator, now i just put a new one on and it still does not charge the battery. What could it be??? __________________ Life is good in the bay.

04-24-2004, 11:10 PM	#2
FastBack 240 Zilvia Addict Join Date: Dec 2002 Location: Motor City......MI Age: 39 Posts: 859 Trader Rating: (0) Feedback Score: 0 reviews	Check and make sure you have a strong enough ground. If your grond is shitty then you wont hold a charge. __________________

04-25-2004, 01:50 PM	#3
Eternal_240Sx Zilvia Addict Join Date: Dec 2002 Location: norcal, bay area Age: 41 Posts: 674 Trader Rating: (1) Feedback Score: 1 reviews	how do i know if its strong enought ground or not. I think there is one pluge and 2 other wires to it. The 2 wires are ground? __________________ Life is good in the bay.

04-25-2004, 07:30 PM	#5
Eternal_240Sx Zilvia Addict Join Date: Dec 2002 Location: norcal, bay area Age: 41 Posts: 674 Trader Rating: (1) Feedback Score: 1 reviews	hmm.. im sorry its not a new one, its actually a used one from my friend who also has a redtop. His was working when he took it off and eventually gave it to me. __________________ Life is good in the bay.

04-25-2004, 02:19 PM	#4
DS 240R Leaky Injector Join Date: Jul 2003 Location: LA, CA, in the shop... Posts: 79 Trader Rating: (0) Feedback Score: 0 reviews	Either get a Consult, nProbe, Techtom or voltmeter to check the voltage. You may have a problem with your ground or with your voltage regulator. When you said "new" alternator, did you get a brand new one or a "remanufactured" one from an auto parts store. I went through three "new" alternators on my car before I just fixed the voltage regulator on a reman'ed OEM one. In my experience, 2 out of 3 auto part store alternators are bad or fail right away.

04-25-2004, 07:53 PM	#6
DS 240R Leaky Injector Join Date: Jul 2003 Location: LA, CA, in the shop... Posts: 79 Trader Rating: (0) Feedback Score: 0 reviews	Well, I'd check your idle voltage then. Techtom or nProbe is the easiest, it should be around 13.5 volts, plus or minus a little. You can also use a voltmeter- just ground the one and put the positive on the positive terminal on the alternator. When my alternator was going bad, it was around 11 or low 12.x volt range. Make sure the car is running when you check Usually the alternator coil is fine and just the voltage regulator is toast. I know on the B13 and B14 SR20 the VR is integral into alternator, so you have to take it apart to replace. I'm not sure about the JDM DET alternator- I know it is different, but probably the same design.