It took me 3 hours by myself to replace the alternator on my daughter's '02 Pathfinder LE tonight. Not the easiest job but nowhere near the PITA that I was led to believe it would be. I'm sure the fact that it is RWD made it easier without all of the extra running gear up front. Overall I am glad I replaced it myself instead of taking it somewhere.
Symptoms were the brake and battery lights came on and eventually the battery was drained. I bought an OEM Nissan alternator figuring it would be the most reliable. Some notes:
- I put the front up on ramps which made working underneath easier.
- I completely removed the battery and was able to disconnect the snap-in plug as well as the big wire under the black rubber cover from above. A ratcheting wrench came in handy.
- Underneath I removed the plastic shield, the big H shaped brace, the sway bar brackets (so the sway bar could drop down), the entire idler pulley with bracket, and the lower part of the fan shroud. With all of this removed I had much more room to work and was easily able to get the alternator out and back in.
- About the big wiring harness attached to the back of the alternator, instead of trying to release the clamp I just used a long screw driver and popped the whole thing off of the metal tab.
- When I was reinstalling the big wire in my haste to get it done I didn't line up the tabs on the eyelet to the slots in the black plastic piece where it bolts onto the alternator and ended up breaking part of the plastic piece off. The black rubber boot still covers it all so I'm not worried about it.
Anyway, if you have a RWD Pathfinder and are a determined DIY'er like myself then the job is definitely doable.
3 hours to replace an alternator...
-
GrubyFngaz
- Posts: 459
- Joined: Wed Jul 24, 2002 2:31 am
- Car: 2001 Infiniti QX4
Re: 3 hours to replace an alternator...
Dude, if you did it that quick you are twice the mechanic I am, lol. Took me a minimum of 6 hours and a lot of cussing and a lot of frustration. Guess I'm still glad I saved the money in the end, but whew, probably the worst thing I've done on a car to date.
Re: 3 hours to replace an alternator...
Don't know what to tell you, I am not a professional mechanic nor do I have any professional training. I don't have a ton of tools but a few things like ratcheting wrenches really help.
Is your QX4 RWD or 4x4? My Pathfinder is 2WD so I think that helped with having more access. Removing the things I mentioned in my original post made things much easier, in fact it didn't look like it was possible without removing it all. Being a 2WD I felt there was a decent amount of space to see and reach behind the alternator from below. I have no idea what it's like on a 4WD model but I would assume there's a lot more stuff in the way blocking access to the back of it.
I wish I had taken pictures but here's the order of steps that I did:
1. Put the front up on Rhino ramps.
2. Disconnected and removed the battery from the vehicle.
3. With the battery removed I could reach down and unplug the electrical connector from the alternator. Like all of those types of connectors there is a tab on one side that you have to press to release it. Mine was fairly easy to press and the connector came right out when I did. Sometimes they are not so easy so be careful.
4. From up top I pushed back the black rubber boot off of the main wire coming off the alternator and was able to remove the nut with a ratcheting wrench (not a ratchet & socket). Somewhat working blind & by feel as once I had the wrench on the nut my arm was blocking the view. Not a lot of room to work the wrench either but enough to get it done. I think it would've been much harder from below.
5. Removed the engine splash shield.
6. Removed the "H" shaped brace that connects the subframe to the lower radiator support.
7. Removed the sway bar brackets so that the sway bar could hang down.
8. Removed the lower radiator fan shroud.
9. Loosened the belt tension and removed the belt from the alternator & pulley and tucked it up out of the way.
10. Removed the entire idler pulley assembly (bracket is held on by 3 bolts, may have to remove the pulley itself first to get to one of the bracket bolts).
11. Remove the 2 alternator mounting bolts. The long upper bolt has a square nut on the back that is loose. To prevent it from falling and getting lost after I removed the bolt I used my extending magnetic pick-up tool and just stuck it onto the nut so it wouldn't drop out and get lost.
12. There is a big wiring harness with a plastic clip that snaps onto the tab of a metal bracket that is bolted onto the back of the alternator. Looking up at the bottom of the plastic clip there is a spot where you can see how the clip snaps onto the tab. I used a long flat bladed screwdriver to release the clip off of the metal bracket by pushing on that spot. Once the alternator is removed you can swap the metal bracket over to the new alternator.
13. There is one last ground wire bolted to the back of the alternator. With the alternator free from its mounts and able to wiggle a bit I used a 1/4" ratchet with a long extension to remove the bolt.
14. At this point the alternator was now free to come out. The fan has 2 blades that are spaced further apart than the others, spin the fan around so you can use that space to maneuver the alternator out.
15. With the old alternator out swap the metal bracket over to the new alternator.
16. Maneuver the new alternator into place but don't line it up on the mounting spots just yet as you need some flexibility to attach the big wiring harness and ground wire.
17. Wiggle the alternator as needed to get the metal bracket tab to line up with the plastic clip of the wiring harness. Once it is then just push it on.
18. Reconnect the ground wire with the small bolt. I know, easier said than done but with the alternator still "loose" I was able to get it in there.
19. The alternator can now put into mounted position and bolted up. For the long bolt I pushed it through so just a short bit of it was sticking out the back, like 1/4" worth. With a pair of long needle nose pliers I held the square nut up to the end of the bolt then started started turning the bolt until it threaded into the nut. Luckily it didn't take much to get threaded in and once it is the nut is designed so it won't keep spinning so you can let go of it and tighten up the bolt.
20. Reinstall the idler pulley & bracket, "H" brace, sway bar brackets, lower fan shroud, and splash shield in the opposite order that you removed them.
21. From up top reconnect the main power wire to the alternator. Just like when it was removed you will be somewhat working blind and by feel but use a ratcheting wrench again. Keep in mind that the end of the wire that fits over the threaded stud has tabs that fit into cutouts of the plastic piece that the stud is through. If you don't line up the tabs into the cutouts then you will break the plastic piece like I did (doh!) when it is tightened down. Make sure the rubber boot is put back into place after it is connected.
22. Plug the electrical connector into the alternator.
23. Reinstall the battery.
24. Double check everything and if it's all good fire it up.
Is your QX4 RWD or 4x4? My Pathfinder is 2WD so I think that helped with having more access. Removing the things I mentioned in my original post made things much easier, in fact it didn't look like it was possible without removing it all. Being a 2WD I felt there was a decent amount of space to see and reach behind the alternator from below. I have no idea what it's like on a 4WD model but I would assume there's a lot more stuff in the way blocking access to the back of it.
I wish I had taken pictures but here's the order of steps that I did:
1. Put the front up on Rhino ramps.
2. Disconnected and removed the battery from the vehicle.
3. With the battery removed I could reach down and unplug the electrical connector from the alternator. Like all of those types of connectors there is a tab on one side that you have to press to release it. Mine was fairly easy to press and the connector came right out when I did. Sometimes they are not so easy so be careful.
4. From up top I pushed back the black rubber boot off of the main wire coming off the alternator and was able to remove the nut with a ratcheting wrench (not a ratchet & socket). Somewhat working blind & by feel as once I had the wrench on the nut my arm was blocking the view. Not a lot of room to work the wrench either but enough to get it done. I think it would've been much harder from below.
5. Removed the engine splash shield.
6. Removed the "H" shaped brace that connects the subframe to the lower radiator support.
7. Removed the sway bar brackets so that the sway bar could hang down.
8. Removed the lower radiator fan shroud.
9. Loosened the belt tension and removed the belt from the alternator & pulley and tucked it up out of the way.
10. Removed the entire idler pulley assembly (bracket is held on by 3 bolts, may have to remove the pulley itself first to get to one of the bracket bolts).
11. Remove the 2 alternator mounting bolts. The long upper bolt has a square nut on the back that is loose. To prevent it from falling and getting lost after I removed the bolt I used my extending magnetic pick-up tool and just stuck it onto the nut so it wouldn't drop out and get lost.
12. There is a big wiring harness with a plastic clip that snaps onto the tab of a metal bracket that is bolted onto the back of the alternator. Looking up at the bottom of the plastic clip there is a spot where you can see how the clip snaps onto the tab. I used a long flat bladed screwdriver to release the clip off of the metal bracket by pushing on that spot. Once the alternator is removed you can swap the metal bracket over to the new alternator.
13. There is one last ground wire bolted to the back of the alternator. With the alternator free from its mounts and able to wiggle a bit I used a 1/4" ratchet with a long extension to remove the bolt.
14. At this point the alternator was now free to come out. The fan has 2 blades that are spaced further apart than the others, spin the fan around so you can use that space to maneuver the alternator out.
15. With the old alternator out swap the metal bracket over to the new alternator.
16. Maneuver the new alternator into place but don't line it up on the mounting spots just yet as you need some flexibility to attach the big wiring harness and ground wire.
17. Wiggle the alternator as needed to get the metal bracket tab to line up with the plastic clip of the wiring harness. Once it is then just push it on.
18. Reconnect the ground wire with the small bolt. I know, easier said than done but with the alternator still "loose" I was able to get it in there.
19. The alternator can now put into mounted position and bolted up. For the long bolt I pushed it through so just a short bit of it was sticking out the back, like 1/4" worth. With a pair of long needle nose pliers I held the square nut up to the end of the bolt then started started turning the bolt until it threaded into the nut. Luckily it didn't take much to get threaded in and once it is the nut is designed so it won't keep spinning so you can let go of it and tighten up the bolt.
20. Reinstall the idler pulley & bracket, "H" brace, sway bar brackets, lower fan shroud, and splash shield in the opposite order that you removed them.
21. From up top reconnect the main power wire to the alternator. Just like when it was removed you will be somewhat working blind and by feel but use a ratcheting wrench again. Keep in mind that the end of the wire that fits over the threaded stud has tabs that fit into cutouts of the plastic piece that the stud is through. If you don't line up the tabs into the cutouts then you will break the plastic piece like I did (doh!) when it is tightened down. Make sure the rubber boot is put back into place after it is connected.
22. Plug the electrical connector into the alternator.
23. Reinstall the battery.
24. Double check everything and if it's all good fire it up.