The Three Amigo's - Weird electrical fault

[nwoods]

My Monty has been a bit persnickety lately. Recently had to replace the brake switch (though after about 200,000 miles, it was due), but last night the Monty surprised me with a weird combination electrical fault. The ABS light came on, the gauge cluster on the top dash (compass, oil pressure, and voltage gauges) died, and the radio died. And then they came back on. And then they died again. And then they came back on.... and then they died again.

I checked all the fuses, all appear okay. No clue why the radio and ABS would be on a related circuit. Not sure how to trouble shoot this. Any suggestions?

Edit: 1998 Gen 2.5 Montero with Winter Package

 

[DSouth]

I've had strangeness like that on other cars when the battery was about to die. They would get more and more frequent until one day it wouldn't start. Start with the simple stuff first.

 

[nwoods]

Fairly new battery and alternator. Both about a year old. Although I think my alternator is crap. Lights pulse and flicker in time to the beat of the engine. It's such a PIA to change out the alternator though, I've been reluctant to pull it and take it in for testing or replacement.

 

[nwoods]

Okay, I don't know what the symptoms of a failing alternator are, but I am experiencing some weird stuff. At low idle my voltage meter is about 9 volts. At fast idle, about 12 volts, and driving, it's maxing out and pegging the meter over 16 volts. All the light bulbs are super bright, even the headlights.

Is there a voltage regulator that might have failed? Is my alternator sending too much current through the system?

 

[nwoods]

I just found this diagram, that suggests the voltage regulator is inside the alternator. Is that correct?

 

[tyty13]

Auto zone dose a free charging system test

 

[nwoods]

Auto zone dose a free charging system test

THey said no, they want to remove the alternator first.

 

[JamesW]

Sounds like the regulator could be busted. It's probably a better bet to fit a different alternator if you haven't any faith in that one though.

Could also be bad earthing between the body and the battery,had it happen in my Jimny,it would give electrical faults,that would go away on their own,it was the earthing strap between the battery and the body had a loose bolt and would break contact now and again,though the 16V is a bit of a giveaway it is the alternator,it doesn't cost anything to put a bit of contact goo on the earthing strap

 

[Jay Ayala]

James, I assume earthing strap is Irish for ground strap? I've never heard that term before but I like it. I think I'll start using it from now on.

 

[billygoats]

Really sounds like a bad alternator. If oil drips on it, they go south very quickly! Removal shouldn't take more than an hour. Remove the airbox. It comes out easy through the top.

 

[plh]

and you are roasting your battery at 16v.

 

[JamesW]

James, I assume earthing strap is Irish for ground strap? I've never heard that term before but I like it. I think I'll start using it from now on.

It must be,earth is usually used in mains electric speak,but here it seems to be used for cars too. Never actually thought about it until now,and I work in electronic design,and always use the term ground there,but always say earth on cars.

going to be really noticing that from now on :sombrero:

Most of the electronic stuff in your truck should be able to survive the extra voltage,but personally I'd avoid running it,as if it makes a big spike it could do a lot of damage to ECUs for the engine or gearbox,and any aftermarket alarm or immobiliser that could be a giant PITA for you later on

 

[nwoods]

The plan was to park the Monty until I had time to pull the alternator, but then my Volvo died all of a sudden, like 10 miles into a trip to Vegas for a tournament. Circled back home and loaded the truck with all the gear and hoping for the best. Timing could not have been worse!

 

[nwoods]

Back from Vegas, survived the NASCAR fans on the road (holy crap can they not drive when rubber necking at all the bright lights and fancy buildings). Pulled the alternator out (was super easy thanks to Brian's tip about simply pulling the aircleaner box out for access). Brought back to Autozone for testing, and it IMMEADIATELY failed in all categories tested. So they thought maybe it was hooked up wrong, and retested it. Again, immediate fail. Third time just for kicks, FAIL.

Unfortunately, no alternators in stock....anywhere in OC. I called Autozone, Oreillys, Sears, NAPA, etc... Zip, nada, zilch. So I drove to LA and got the one and only stocked item listed by PepBoys. It was a new unit, not a reman, for $233. Installation went easy, and tada! Everything appears to work correctly.

Took the old alternator back to Autozone and they gave me $250 back. Sweet! I only paid $188 originally, so I guess I got a core charge credit also?
I am a happy camper. Now to figure out what happened to the Volvo.... Sometimes I hate having my "new car" be a 9 year old Nissan Armada with 105k on it. Everything else in the home fleet is just aging too fast to keep up with!

 

[billygoats]

Good news to hear Nathan! Glad you got it worked out, and post like this can be archived for anyone with the same symptoms!