Is it the alternator?

[Jupit3r]

Hi y'all,
I just bought a 2002 Pathfinder LE two weeks ago. Last night I was backing down a ramp driveway and heard a thud/clunk, then she died and wouldn't turn over. No lights or battery operated systems worked, but a faint click click click click sound when the key was turned on. The valet of a nearby restaurant helped me push her off to the grass out of traffic. Tow truck arrived and jumped it, but died 30 seconds later so he towed it to my house, jumped it again, and it held charge long enough for me to put it in driveway.
While I was waiting for auto club, I texted my exhusband (aircraft mechanic) who is not convinced it is alternator. Because of the clunk and the clicking. I'm about to go get a new alternator and battery for a starting point.
In the meantime, any thoughts or suggestions are welcome. I have zero mechanical skills but I guess it is never too late to learn.
Thanks!

[Buzzman]

I would tend to agree with your ex on this one.
Alternators don't usually fail with a clunk (unless something physically has broken off.).
They fail when they don't keep the battery charged anymore, and that is usually a soft failure, not a hard failure like you experienced.
When my alternator died, the first thing that started happening is that the warning lights on the dash all started lighting up. The truck ran for a few more miles after that, until the battery became too weak to keep it running.
I was able to take the battery home, recharge it, and reinstall it. It ran long enough for me to get it home.
Check under the hood for anything obvious that may have broken (serpentine belt???).

[Jupit3r]

Thanks, Buzzman. I had the Serpentine belt changed a week ago. I looked under hood after reading your reply, thinking it may have popped off and made that noise but it looks ok to me and feels snug. Also, the relay box is chattering (ex told me that's what it's called), even with or off. Seems to be coming from headlamp relay but I can't be sure.
I ordered an alternator to be delivered next week and he will get a battery too. My friend can do install. Thanks!

[Buzzman]

Also, the relay box is chattering (ex told me that's what it's called), even with or off. Seems to be coming from headlamp relay but I can't be sure.
I ordered an alternator to be delivered next week and he will get a battery too. My friend can do install. Thanks!

Whoa, I would hold off installing the alternator and battery until you do some proper troubleshooting, especially the alternator.
The alternator is a major PIA to replace if you do it yourself. You have to take it out from the bottom, from underneath the engine.
You cannot remove it from the top of the engine. Trust me, it's brutal.
You can do search on this subject and find some tips, if you insist on replacing it.
Start by getting a volt meter and at least check the battery to see what you get.
No sense going to all that trouble and expense, and then finding out that the alternator and battery were not the problem.
One last tip: If it is the alternator, and the old battery is dead as a result, then the truck should still start and run with a fully charged replacement battery.
You don't actually need a working alternator to get it to run. (it just won't run for very long.)
If it doesn't start and run with a fresh battery, then you have other problems.

[Blindaviator]

Best way to tell if it's an alternator... Take the battery down to Auto parts store and have them charge / test it (assuming you don't have a battery charger)... Put the battery back in and start it up... If it stays running then put a volt meter on the battery terminals and watch the voltage... If it steadily goes down then it is a problem with the charging system...

The voltage should stay between about 13.5 to 14.5 volts... If not then there is a problem with charging... Alternator, charging wire or fusible link...

Whatever you do for testing DO NOT disconnect the battery terminals while it's running to test charging... If you do the voltage may spike and fry the the ECU...

I changed my alternator twice in the last 2 months... Remove the belt, remove upper radiator hose, remove the cooling fan and fan shroud (the fan shroud splits apart so you can remove it easily), remove alternator.... Put new alternator in and reinstall everything...

The hardest part of the whole thing is removing and reattaching the charging wire from the rear of the alternator... I found it made it a LOT easier to pull the 2 bolts holding the power steering pump to the engine which allows you to move it out of the way enough to reach the back of the alternator... The top bolt on the alternator has a self holding nut on the back side that you have to hold in place to tighten it back properly (it has a tab on it that it uses to hold it's self in place)... With the power steering pump mounted it is VERY difficult to reach that nut to loosen or tighten the bolt..

[PathyPop]

Whoa, I would hold off installing the alternator and battery until you do some proper troubleshooting, especially the alternator.

Ditto on this ^. Even easier than using a voltmeter, you can plug this basic tester in the lighter socket to fairly definitively test both the alternator and the battery. Very useful when buying a used car. The led lights are self explanatory. When testing the battery using this device, try to leave the headlights on for 5 minutes (engine off) to get a more accurate reading (removes the surface charge).

https://www.amazon.com/Cal-Hawk-Cigaret ... tor+tester

Available at Autozone, Walmart, etc, too. If your battery has been left in a run-down state for any length of time, or a few times (which sounds like the case with your PF), for most batteries they will become marginal and need to be replaced. As mentioned, you don't want to spend a lot on parts you may not need. Good that you have a friend to help. Don't go to the dealer, find a good, recommended and/or well reviewed independent mechanic first.

Good luck and let us know how it goes.

[Jupit3r]

It's a 3 yr old battery so I don't mind replacing it, but before I do anything, I want to check into the strut tower. Now that I know she lived her early years in New York, I'm getting nervous about that. I forgot to mention the relay box has been ticking away since Saturday. Seems loudest around the relay labeled headlamp. I can hear it now through the window because it is parked right next to it.

[Jupit3r]

Thanks everyone, I do want to pick up that battery tester. Changing anything myself is unlikely, but I like to at least try to understand the problem. I'm lucky that I have a friend who is a bit on hard times but great at fixing things so he's happy to work on it for a fraction of what shop labor would charge. He will be here tomorrow to work on it, so fingers crossed that he finds no rust on the strut tower (will take it to dealer later to inspect properly), and that the battery alternator relay noise can get her back on the road.

[Jupit3r]

Ok. Battery is charged and still won't crank. No lights no nothing. Discovered carpet under driver mat is soaked. Feels and smells like water. Thoughts?

[Blindaviator]

No power to anything I would check fuses first thing.

Water on floor is likely a leak from maybe the windshield, drivers side window or sun roof (if equipped). Get inside it and close it up tight, have a friend run a water hose over all the door and window seams on that side and look for drips. It's possible that if the windshield is leaking it may have dripped into wiring and caused fuses to blow.

[Blindaviator]

It's a 3 yr old battery so I don't mind replacing it, but before I do anything, I want to check into the strut tower. Now that I know she lived her early years in New York, I'm getting nervous about that. I forgot to mention the relay box has been ticking away since Saturday. Seems loudest around the relay labeled headlamp. I can hear it now through the window because it is parked right next to it.

If you still hear the ticking then start pulling the relays one at a time until it stops. That will tell you at least partially what an issue could be.

[Buzzman]

Ok. Battery is charged and still won't crank. No lights no nothing. Discovered carpet under driver mat is soaked. Feels and smells like water. Thoughts?

Have a look through this thread on the water issue. It's not uncommon, unfortunately.
topic503477.html?hilit=water%20in%20passenger

As for the battery/no start issue, you definitely need to figure out what's going on with the electrical noise.
I suspect that's where the real problem is, and not with the battery or the alternator. Good luck.

[Jupit3r]

Thanks, guys! So, we did change alternator and battery and all is good, so far. I def agree that water on fuses and/or the relay for headlamps is still a potential problem. I'm into this thing for enough dough now that I will be taking advantage of the experts here as I get this rig back in shape. Thanks again.

[PathyPop]

Good to hear that you got it fixed! My son's 2003 Pathfinder 4x4 cost $3500 and I told him that even after we included known repair costs he should still budget 10-20% for repairs and maintenance we didn't catch or were not told about. After two months only $200 spent, so far so good, but tires and suspension will be needed by year end.

[Jupit3r]

Well, folks, I spoke too soon. She's kaput again, despite firing up and running fine after the new alternator & battery installation. The relay box is chattering again, and the truck is dead again. The starter appears new, so we are stumped.

[Jupit3r]

I agree it is the electrical--either the relay box or the wiring under the dash that gets wet when it rains. Gonna get a tarp today so I can keep it covered for now...

[Buzzman]

Have you pulled or swapped out any of the relays?
I went to the junkyard a few years ago and grabbed a bunch of relays as spares. Cost me pennies. I use them for troubleshooting and repairs.
If you don't have any spare relays, then move a few of them around.
There are more than one of the same type, so swap them around first.
Even though the relay may be the same, they don't all use the same contacts. Depends on their function. That's why swapping them sometimes works.

[Jupit3r]

That is a good idea, and no we have not tried that...my friend is coming back tomorrow afternoon to carry on with it. Picking up some spares is a good idea, too. I will look into that.

[Rockwood]

I had something similar happen a couple of months ago. Everything in the truck died going around a corner. It took me a couple of weeks of off and on troubleshooting to figure it out.

There is a red connector on the side of the positive battery terminal. It has two 8 gauge wires that go to the fuse box behind the battery. Everything in the truck is powered thru those two 8 gauge wires. The inside of the connector had corroded and the wires would not carry enough current, so my truck would randomly just die.

Those wires should detach from the connector easily by pushing down on the lock tabs. If they won't come out, they are corroded in place like mine were, and that could be your problem.

Can't buy that connector separately from the dealer, so I just replaced the positive terminal and put some ring connectors on the ends of the two 8 gauge wires and bolted it all together. It's not pretty, but the truck has not hiccupped since.

It's worth checking!