How to replace alterntor
How to replace alterntor
My car is a 2005 convertible. I am not sure if the later Zs have the same alternator setup. I noticed my volt gauge read about 12 volts after I started up the car one day. After a few seconds, the reading jumped up to 14.1. It stayed there the rest of the trip. The next time I drove the car, it took a bit longer for the volt gauge needle to jump up. Finally, it did not jump at all. The car eventually died as I was driving it. The battery was fairly new. This led me to believe (correctly) that the alternator failed.
I looked online for step by step instructions and didnt find any. On Youtube, the videos I saw were young guys f@#$ing around, flipping each other off, and eventually replacing the alternator. I pulled up the service manual for the car, and figured out what was needed to replace the alternator. I modified some of the steps. Since many many Zs are modified, you will have to take into account your mods. Im not going to post pictures of where the bolts are, or give a list of tools needed because its fairly straightforward. But a step by step makes the job much easier.
1. The car should be cool. Jack up the car, particularly on the passenger side, as that is where the alternator is located. Make sure its secure with jackstands, chock the back wheels...blah blah blah.
2. Roll down the windows part way. This has to do with the door seals.
3. Disconnect the battery. I disconnected both battery leads, REMOVING NEGATIVE LEAD FIRST. They say you do one first, then the other. I forget which but Ive never had a problem disconnecting either one first. Hook up a battery charger to the battery and charge the battery FULLY. I used 2 Amp setting on my battery charger.
4. Disconnect the airbox from the flexible intake tube, and set it up on the engine. The MAP sensor wire will still be attached to the box.
5. Remove the single 10mm bolt that holds the coolant overflow bottle and remove the bottle. This is the time to clean out the inside and outside.
6. The service manual says to drain the coolant. Mine was fresh, so I placed a small container beneath the upper radiator hose and remove the hose from the radiator and caught a bit of spilled coolant in the container. I bent the hose towards the back of the car to make way for the radiator fans.
7. Remove the grey connector that connects to the passenger side fan. I didnt have to remove the drivers side fan connector.
8. Under the car is either a stock undertray splash shield, a metal one like I have (highly recommended), or no tray at all (bad for aerodynamics). Remove about 10 10mm bolts and remove the tray.
9. On the passenger side fan, there is a lower connector. Press the middle and remove that connector. Now go back up top and remove the 2 10mm bolts holding the fans in and wiggle the fans out. Its a tight squeeze but they come out. I removed a bolt on the drivers side to get some metal hoses out of the way.
10. Look for the belt tension pulley. With a 14mm wrench, loosen the center bolt, but dont remove it yet. Now get under the car and you will see a 12mm bolt near the tension pulley that faces downward. Loosen that 12mm bolt and you will see the belt tension loosen. Keep loosening it until you can remove the serpentine belt. I removed the belt tension pulley and noticed it made noise when I spun it. It also felt a bit rough when I spun it. This means the bearing are going bad. I bought one at Autozone for about $50. If the tensioner seizes, it could throw the belt and strand you. Just replace it if you have doubts.
11. At the bottom corner of the engine is the oil pressure sensor. Remove the connector (I think you press the center and pull it out)
12. While under the car, look for a metal bracket that attaches to the alternator and then to the engine with 12mm bolts. Remove those bolts.
13. Just above the alternator is a long 14mm bolt. This is why the fans come out because the bolt holds the alternator in place. I needed a breaker bar to break the bolt loose! Anyway, loosen the bolt and pull it out. Now the alternator should come free from the engine but is still attached by the positive heavy wire from the battery, a wire connector (3 wires I think), and a bracket with 2 8mm bolts.
14. I pulled the alternator down and removed the 2 8mm bolts holding that bracket on. There was a hose in that bracket, so I pushed the hose away to give me more room. The heavy gauge battery wire terminal is covered by a thick rubber cover. Pull the cover away and unscrew the nut holding the wire on the alternator. Push down on the center of the multiwire connector and the alternator should be free from the engine completely. Wrestle it around the anti-sway bar and take it down to where you buy your new alternator to match it up. They usually want your old alternator for a core.
Installation is literally the reverse of removal. I had a bit of trouble getting the long bolt to bite into the captured nut on the alternator. I suggest cleaning your hands well so the alternator isnt so slippery. Also, I cleaned the area under the engine some. Everything else was straighforward. Make sure the battery is fully charged.
When I started the car, the volt gauge needle shot up to 14.2 and stayed there. Yours should too. Job done.
If you have questions or want pictures or some other clarification, let me know.
I looked online for step by step instructions and didnt find any. On Youtube, the videos I saw were young guys f@#$ing around, flipping each other off, and eventually replacing the alternator. I pulled up the service manual for the car, and figured out what was needed to replace the alternator. I modified some of the steps. Since many many Zs are modified, you will have to take into account your mods. Im not going to post pictures of where the bolts are, or give a list of tools needed because its fairly straightforward. But a step by step makes the job much easier.
1. The car should be cool. Jack up the car, particularly on the passenger side, as that is where the alternator is located. Make sure its secure with jackstands, chock the back wheels...blah blah blah.
2. Roll down the windows part way. This has to do with the door seals.
3. Disconnect the battery. I disconnected both battery leads, REMOVING NEGATIVE LEAD FIRST. They say you do one first, then the other. I forget which but Ive never had a problem disconnecting either one first. Hook up a battery charger to the battery and charge the battery FULLY. I used 2 Amp setting on my battery charger.
4. Disconnect the airbox from the flexible intake tube, and set it up on the engine. The MAP sensor wire will still be attached to the box.
5. Remove the single 10mm bolt that holds the coolant overflow bottle and remove the bottle. This is the time to clean out the inside and outside.
6. The service manual says to drain the coolant. Mine was fresh, so I placed a small container beneath the upper radiator hose and remove the hose from the radiator and caught a bit of spilled coolant in the container. I bent the hose towards the back of the car to make way for the radiator fans.
7. Remove the grey connector that connects to the passenger side fan. I didnt have to remove the drivers side fan connector.
8. Under the car is either a stock undertray splash shield, a metal one like I have (highly recommended), or no tray at all (bad for aerodynamics). Remove about 10 10mm bolts and remove the tray.
9. On the passenger side fan, there is a lower connector. Press the middle and remove that connector. Now go back up top and remove the 2 10mm bolts holding the fans in and wiggle the fans out. Its a tight squeeze but they come out. I removed a bolt on the drivers side to get some metal hoses out of the way.
10. Look for the belt tension pulley. With a 14mm wrench, loosen the center bolt, but dont remove it yet. Now get under the car and you will see a 12mm bolt near the tension pulley that faces downward. Loosen that 12mm bolt and you will see the belt tension loosen. Keep loosening it until you can remove the serpentine belt. I removed the belt tension pulley and noticed it made noise when I spun it. It also felt a bit rough when I spun it. This means the bearing are going bad. I bought one at Autozone for about $50. If the tensioner seizes, it could throw the belt and strand you. Just replace it if you have doubts.
11. At the bottom corner of the engine is the oil pressure sensor. Remove the connector (I think you press the center and pull it out)
12. While under the car, look for a metal bracket that attaches to the alternator and then to the engine with 12mm bolts. Remove those bolts.
13. Just above the alternator is a long 14mm bolt. This is why the fans come out because the bolt holds the alternator in place. I needed a breaker bar to break the bolt loose! Anyway, loosen the bolt and pull it out. Now the alternator should come free from the engine but is still attached by the positive heavy wire from the battery, a wire connector (3 wires I think), and a bracket with 2 8mm bolts.
14. I pulled the alternator down and removed the 2 8mm bolts holding that bracket on. There was a hose in that bracket, so I pushed the hose away to give me more room. The heavy gauge battery wire terminal is covered by a thick rubber cover. Pull the cover away and unscrew the nut holding the wire on the alternator. Push down on the center of the multiwire connector and the alternator should be free from the engine completely. Wrestle it around the anti-sway bar and take it down to where you buy your new alternator to match it up. They usually want your old alternator for a core.
Installation is literally the reverse of removal. I had a bit of trouble getting the long bolt to bite into the captured nut on the alternator. I suggest cleaning your hands well so the alternator isnt so slippery. Also, I cleaned the area under the engine some. Everything else was straighforward. Make sure the battery is fully charged.
When I started the car, the volt gauge needle shot up to 14.2 and stayed there. Yours should too. Job done.
If you have questions or want pictures or some other clarification, let me know.
Last edited by DeusExMaxima; Jan 21, 2020 at 09:23 AM.
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Joined: Dec 2013
Posts: 1,051
Likes: 318
From: West Coast, Florida
My car is a 2005 convertible. I am not sure if the later Zs have the same alternator setup. I noticed my volt gauge read about 12 volts after I started up the car one day. After a few seconds, the reading jumped up to 14.1. It stayed there the rest of the trip. The next time I drove the car, it took a bit longer for the volt gauge needle to jump up. Finally, it did not jump at all. The car eventually died as I was driving it. The battery was fairly new. This led me to believe (correctly) that the alternator failed.
I looked online for step by step instructions and didnt find any. On Youtube, the videos I saw were young guys f@#$ing around, flipping each other off, and eventually replacing the alternator. I pulled up the service manual for the car, and figured out what was needed to replace the alternator. I modified some of the steps. Since many many Zs are modified, you will have to take into account your mods. Im not going to post pictures of where the bolts are, or give a list of tools needed because its fairly straightforward. But a step by step makes the job much easier.
1. The car should be cool. Jack up the car, particularly on the passenger side, as that is where the alternator is located. Make sure its secure with jackstands, chock the back wheels...blah blah blah.
2. Roll down the windows part way. This has to do with the door seals.
3. Disconnect the battery. I disconnected both battery leads. They say you do one first, then the other. I forget which but Ive never had a problem disconnecting either one first. Hook up a battery charger to the battery and charge the battery FULLY. I used 2 Amp setting on my battery charger.
4. Disconnect the airbox from the flexible intake tube, and set it up on the engine. The MAP sensor wire will still be attached to the box.
5. Remove the single 10mm bolt that holds the coolant overflow bottle and remove the bottle. This is the time to clean out the inside and outside.
6. The service manual says to drain the coolant. Mine was fresh, so I placed a small container beneath the upper radiator hose and remove the hose from the radiator and caught a bit of spilled coolant in the container. I bent the hose towards the back of the car to make way for the radiator fans.
7. Remove the grey connector that connects to the passenger side fan. I didnt have to remove the drivers side fan connector.
8. Under the car is either a stock undertray splash shield, a metal one like I have (highly recommended), or no tray at all (bad for aerodynamics). Remove about 10 10mm bolts and remove the tray.
9. On the passenger side fan, there is a lower connector. Press the middle and remove that connector. Now go back up top and remove the 2 10mm bolts holding the fans in and wiggle the fans out. Its a tight squeeze but they come out. I removed a bolt on the drivers side to get some metal hoses out of the way.
10. Look for the belt tension pulley. With a 14mm wrench, loosen the center bolt, but dont remove it yet. Now get under the car and you will see a 12mm bolt near the tension pulley that faces downward. Loosen that 12mm bolt and you will see the belt tension loosen. Keep loosening it until you can remove the serpentine belt. I removed the belt tension pulley and noticed it made noise when I spun it. It also felt a bit rough when I spun it. This means the bearing are going bad. I bought one at Autozone for about $50. If the tensioner seizes, it could throw the belt and strand you. Just replace it if you have doubts.
11. At the bottom corner of the engine is the oil pressure sensor. Remove the connector (I think you press the center and pull it out)
12. While under the car, look for a metal bracket that attaches to the alternator and then to the engine with 12mm bolts. Remove those bolts.
13. Just above the alternator is a long 14mm bolt. This is why the fans come out because the bolt holds the alternator in place. I needed a breaker bar to break the bolt loose! Anyway, loosen the bolt and pull it out. Now the alternator should come free from the engine but is still attached by the positive heavy wire from the battery, a wire connector (3 wires I think), and a bracket with 2 8mm bolts.
14. I pulled the alternator down and removed the 2 8mm bolts holding that bracket on. There was a hose in that bracket, so I pushed the hose away to give me more room. The heavy gauge battery wire terminal is covered by a thick rubber cover. Pull the cover away and unscrew the nut holding the wire on the alternator. Push down on the center of the multiwire connector and the alternator should be free from the engine completely. Wrestle it around the anti-sway bar and take it down to where you buy your new alternator to match it up. They usually want your old alternator for a core.
Installation is literally the reverse of removal. I had a bit of trouble getting the long bolt to bite into the captured nut on the alternator. I suggest cleaning your hands well so the alternator isnt so slippery. Also, I cleaned the area under the engine some. Everything else was straighforward. Make sure the battery is fully charged.
When I started the car, the volt gauge needle shot up to 14.2 and stayed there. Yours should too. Job done.
If you have questions or want pictures or some other clarification, let me know.
I looked online for step by step instructions and didnt find any. On Youtube, the videos I saw were young guys f@#$ing around, flipping each other off, and eventually replacing the alternator. I pulled up the service manual for the car, and figured out what was needed to replace the alternator. I modified some of the steps. Since many many Zs are modified, you will have to take into account your mods. Im not going to post pictures of where the bolts are, or give a list of tools needed because its fairly straightforward. But a step by step makes the job much easier.
1. The car should be cool. Jack up the car, particularly on the passenger side, as that is where the alternator is located. Make sure its secure with jackstands, chock the back wheels...blah blah blah.
2. Roll down the windows part way. This has to do with the door seals.
3. Disconnect the battery. I disconnected both battery leads. They say you do one first, then the other. I forget which but Ive never had a problem disconnecting either one first. Hook up a battery charger to the battery and charge the battery FULLY. I used 2 Amp setting on my battery charger.
4. Disconnect the airbox from the flexible intake tube, and set it up on the engine. The MAP sensor wire will still be attached to the box.
5. Remove the single 10mm bolt that holds the coolant overflow bottle and remove the bottle. This is the time to clean out the inside and outside.
6. The service manual says to drain the coolant. Mine was fresh, so I placed a small container beneath the upper radiator hose and remove the hose from the radiator and caught a bit of spilled coolant in the container. I bent the hose towards the back of the car to make way for the radiator fans.
7. Remove the grey connector that connects to the passenger side fan. I didnt have to remove the drivers side fan connector.
8. Under the car is either a stock undertray splash shield, a metal one like I have (highly recommended), or no tray at all (bad for aerodynamics). Remove about 10 10mm bolts and remove the tray.
9. On the passenger side fan, there is a lower connector. Press the middle and remove that connector. Now go back up top and remove the 2 10mm bolts holding the fans in and wiggle the fans out. Its a tight squeeze but they come out. I removed a bolt on the drivers side to get some metal hoses out of the way.
10. Look for the belt tension pulley. With a 14mm wrench, loosen the center bolt, but dont remove it yet. Now get under the car and you will see a 12mm bolt near the tension pulley that faces downward. Loosen that 12mm bolt and you will see the belt tension loosen. Keep loosening it until you can remove the serpentine belt. I removed the belt tension pulley and noticed it made noise when I spun it. It also felt a bit rough when I spun it. This means the bearing are going bad. I bought one at Autozone for about $50. If the tensioner seizes, it could throw the belt and strand you. Just replace it if you have doubts.
11. At the bottom corner of the engine is the oil pressure sensor. Remove the connector (I think you press the center and pull it out)
12. While under the car, look for a metal bracket that attaches to the alternator and then to the engine with 12mm bolts. Remove those bolts.
13. Just above the alternator is a long 14mm bolt. This is why the fans come out because the bolt holds the alternator in place. I needed a breaker bar to break the bolt loose! Anyway, loosen the bolt and pull it out. Now the alternator should come free from the engine but is still attached by the positive heavy wire from the battery, a wire connector (3 wires I think), and a bracket with 2 8mm bolts.
14. I pulled the alternator down and removed the 2 8mm bolts holding that bracket on. There was a hose in that bracket, so I pushed the hose away to give me more room. The heavy gauge battery wire terminal is covered by a thick rubber cover. Pull the cover away and unscrew the nut holding the wire on the alternator. Push down on the center of the multiwire connector and the alternator should be free from the engine completely. Wrestle it around the anti-sway bar and take it down to where you buy your new alternator to match it up. They usually want your old alternator for a core.
Installation is literally the reverse of removal. I had a bit of trouble getting the long bolt to bite into the captured nut on the alternator. I suggest cleaning your hands well so the alternator isnt so slippery. Also, I cleaned the area under the engine some. Everything else was straighforward. Make sure the battery is fully charged.
When I started the car, the volt gauge needle shot up to 14.2 and stayed there. Yours should too. Job done.
If you have questions or want pictures or some other clarification, let me know.
Suggestion: please revise your information on which battery terminal to remove. ALWAYS ALWAYS ALWAYSSSS remove the negative terminal first and reconnect it last. NEVER disconnect your positive first. Disconnecting the positive first /reconnecting last is very dangerous and runs the risk of shorting your electrical system and / or delivering a very nasty shock if your wrench slips and connects ground. Disconnecting the ground will cause no harm if you slip and ground your wrench out. This will then render it safe to disconnect the positive. Think of it this way, would you stick a wrench between your positive and negative terminal and connect them together? That is essentially what happens when you leave the negative hooked up and accidently ground the positive / wrench.
Second, unless I am reading it wrong, how did you only have to disconnect one connector to remove the radiator fans? Each fan has a connector for the actual motor, and then another connection about a foot away where each plugs in to the harness from the main harness. You can see the two motor plugs and partially see the other connectors in this pic. Did you disconnect them at some other point where there was only a single connector?
813 350z: Thank you for the suggestions. I added a disconnect the negative lead first to my first post. With respect to the fans, I actually disconnected both fans, but then discovered that the driver side fan did not need disconnecting. If I can find some time this weekend, Ill get some pics of what I disconnected.
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