'87 Pathfinder-Rear wiper won't turn off

[Slartibartfast]

Definitely sounds like your alt is dead. Whether it took the other stuff with it, I have no idea. The regulator is internal. I've never had one fail wide open, or heard of it--I've heard of it happening on an older American pickup, and blowing the bulbs in the dash, but, yeah, no idea what it would do on one of these. I guess if it lost a diode, it might've pumped pulsed DC or even AC into the system, which some components might not have appreciated. Not sure how that would've killed a fuse link, though.

 

FWIW, the 90A alt from a SOHC Maxima bolts right up (just swap the pulley), and when I bought mine, it was actually cheaper than the stock 70A alt. (Yours may have a 60A alt, if it's original.) Same wiring, same belt. I should probably put a thicker charge wire on it one of these days, but so far I've had no trouble with it.

 

The front wiper amp is the brown box hanging off the wiper motor. Low voltage might well explain it not changing speeds, but, yeah, not stopping sounds like a similar fault to your rear amp. I imagine their innards are very similar. Stands to reason whatever killed the rear one, killed the front one too, whether it was the alternator or not.

 

Hopefully the alt was the problem, and a new one makes it stop generating gremlins!

[Fbanks]

On 8/3/2024 at 3:44 AM, Slartibartfast said:

Not sure how that would've killed a fuse link, though.

 

I'm willing to write off that fusible link as just being old and corroded and past its time. My truck is more than 35 years old now, and that link was looking pretty bad and I doubt I'd ever replaced it before. I've been keeping an eye on the replacement, and so far so good there. 

 

On 8/3/2024 at 3:44 AM, Slartibartfast said:

 

FWIW, the 90A alt from a SOHC Maxima bolts right up (just swap the pulley), and when I bought mine, it was actually cheaper than the stock 70A alt. (Yours may have a 60A alt, if it's original.) Same wiring, same belt. I should probably put a thicker charge wire on it one of these days, but so far I've had no trouble with it.

 

That's a great tip and would have been the way I went had I known, but unfortunately, I had already ordered a replacement from RockAuto. I did check out the Maxima alternator, and they actually did have a no-name closeout for $38, which was about half price of what I paid for the AC/Delco 60A. On the plus side, after reading your post, I decided to take a look and see when the last time I replaced my alternator was (I keep pretty good records). In finding my records, I also found that the replacement was a lifetime warranty replacement from Autozone, originally bought in 1997, and replaced once in 2003. Autozone actually took my old unit back and gave me a new replacement, once the guys at the store figured out how to handle something that old. Surprisingly, they still had the warranty in their records (I did have an old receipt too, which wasn't needed), so I gotta give props to AZ on this one.  I never even opened the one from RockAuto, so that one will go back. The AZ unit is just a 60A, but the last one was as well, and I got >20 years out of it, so hopefully this one holds up as well. 

 

On 8/3/2024 at 3:44 AM, Slartibartfast said:

 

The front wiper amp is the brown box hanging off the wiper motor. Low voltage might well explain it not changing speeds, but, yeah, not stopping sounds like a similar fault to your rear amp. I imagine their innards are very similar. Stands to reason whatever killed the rear one, killed the front one too, whether it was the alternator or not.

 

Hopefully the alt was the problem, and a new one makes it stop generating gremlins!

 

I replaced the alternator this weekend, and so far, so good. Dash voltmeter showing 14V now when running, so all's looking good there. I even tested the front wiper and everything seemed to work just fine (other than the spray nozzles needing adjusting), including the delay switch as well. I did see the brown box by the wiper motor, but left well-enough alone for now. As I recall, this problem with the front wiper not turning off until I shut the truck down was intermittent, and would not happen every time. I tried it several times this weekend and couldn't get it to fail. I do recall replacing the multifunction switch on the steering column before, so it's possible I solved those old issues previously , and the undervoltage caused some similar reoccurence. 

 

 

[Slartibartfast]

Hopefully the new alt doesn't give you an excuse to upgrade for a while!