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Hi, im pretty much a noob when it comes to working on cars so i apologize if this is a stupid post.

Basically, a few month back i bought a 1995 240sx with an sr20det swap (as well as the accompanying jdm transmission). There were several issues but most of them are pretty simple to fix even for someone with as little experience as me.

One of the things i noticed off the bat is that the front door speakers were cutting in and out when i tried to play music (not by any means a big issue but it was something i could work on while I was waiting for better weather). So, i popped the door sills off and took out the front speakers. The solder points were rusted so i figured I'd grind them down and reconnect them down the road, or get some better speakers. But, the next time i took the car for a test drive, the battery died.

At first i just figured the alternator had gone, but recntly ive been wondering if removing the speakers and having the wires hanging in the open could be somehow related to the baterry draining so quickly. I ordered a new alternator but it hasnt shipped yet. What im wondering is if i should rewire the speakers and see if the batery holds a charge so i could cancel the order, or if it wouldnt even make a difference?

Again im new to this whole scene. I want to learn everything i can so any help would be appreciated. Thanks in advance.
 

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Sup Mod keeping the peace
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A properly working charging system puts out about 13.2 to 15.0 volts, but this is a general spec. and the factory service manual should be referenced for the correct charging system voltage specifications for a particular vehicle. A battery should have a static charge of 12.2-12.6 volts. If a battery is not good, the charging system may not be able to charge properly. If a vehicle is not charging properly and the battery is good, the first thing to do is to turn the ignition switch to the "ON" position without starting the engine and make sure the charging system warning light is operating. If the bulb is burnt out, the charging system will not charge. If the bulb is OK but still does not illuminate, the circuit must be tested. If the warning lamp does illuminate, then the next thing to check is to make sure the circuit between the battery positive post, or fusible link, to the connection in back of the alternator is good. On Nissans, this will be a thick (approx. 10 gauge) white wire to the "BAT" post on the back of the alternator. It's not uncommon for this wire to get corroded and burn up, creating resistance in the circuit. So, before assuming an alternator is bad, make sure this circuit is good and battery voltage is getting to the alternator. It's also important to make sure the alternator belt is tight and not slipping and the battery connections are clean and tight.

As long as the radio is turned off, there should be no voltage at the speaker wires. With the ignition switch and everything else turned OFF, there should be NO parasitic draw of power from the battery. Insure that your tail lights and interior dome lights are off.

Assuming the charging system voltage is correct and the battery is good, the next thing to do would be to have a parasitic draw test performed; there should not be more than a 50 milliamp draw on the system with the ignition switch in the "OFF" position. If there is a higher draw, you need to do some testing to find out where the draw is coming from. Remove fuses one at a time until the draw goes away or falls into acceptable range.

When replacing electrical components such as alternators, starters and distributors, fuel injectors and sensors, always replace with new or reman'd Nissan OEM components; aftermarket components generally don't last long, don't work right and many times are DOA.
 

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Out of curiosity, can you still buy Nissan OEM parts for a 1995 240SX? Seems to me most aftermarket alternators would be remans. Surely buying one from a quality company such as Denso or AC Delco would be fine?
 

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Sup Mod keeping the peace
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Out of curiosity, can you still buy Nissan OEM parts for a 1995 240SX? Seems to me most aftermarket alternators would be remans. Surely buying one from a quality company such as Denso or AC Delco would be fine?
For a lot of older cars, a Nissan dealership only sells "OEM remans" and yes they also get them from companies like Denso or AC Delco. A retailer like RockAuto also gets them from the same source but charges way less then a dealership. The term re-manufactured usually (not always) refers to a part that, for all practicable purposes, has been completely re-manufactured to the standard of a new part.

The parts you need to avoid are the aftermarket ones, which you see alot on Ebay, that advertise has being "new" or "new improved" and no mention of "OEM re-manufactured". Also to avoid are "OEM rebuilds", a rebuilding company will use a vehicle's old part and replace just the worn components. If the vehicle's old part cannot be rebuilt because it is too worn, they will use a part from another vehicle (referred to as a "core"). If a core is used, than they will replace only what is needed in the core.
 
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