Starting last week I started to experience what I thought was an alternator starting to fail. The first symptoms were voltage spikes that I noticed, where the dash lights would get brighter than normal, the windows would go up and down at warp speed, the heater blower would blow at hurricane strength, and the radio would cut out when revs were above 1100 rpm, then come back on when I came to a stop, or revs dropped below 1100rpm. I figured it was the voltage regulator on the alternator. The syptoms were intermittent, sometimes lasting a couple minutes, and other times lasting a bit under 10 minutes.

I sourced a used alternator off EBAY on monday from a '95 that was totaled in a rear end collision. I figured for $30 I have nothing to lose. It's coming from Pennsylvania to Washington state and Fedex Ground isn't due to deliver it til Saturday. As luck would have it - Mr Murphy decided to visit me at 10am this morning. I was driving along and then the battery light came on and the tach stopped working. I thought - crap, and now the serpentine belt is gone too? There was no change in performance whatsoever. I was only about 3 miles from the bank, so I decided to continue until I got there then check out what was going on under the hood.

After getting to the bank, I looked under the hood and was surprised to see the serpentine belt was just fine. I go into the bank, come back out and try to start. NOTHING. Not a sound. All the dash lights come on, the shift lock clicks, the brake switch is operational, the heater blows at normal strength, the radio comes on, and the windows operate normally - So I know it wasn't a dead battery. The starter was replaced in november, the ground cable was replaced at that time as well. I checked the fuseable link for both the altenator and the ignition and neither are blown.

I parked in front of a womans house across the street from the bank and she saw me under the hood and asked if I needed any help. I decided to ask for a jump just to officially rule that out (and she was a hottie so I was looking for excuses for her to stick around!) The jump was unsuccessful (the car, get your minds out of the gutter) No change. No sound. No click. I had an appt I needed to get to, and the woman offered me a ride in that direction, so I decided to just leave it parked and come back to investigate later. I won't get back over there until tomorrow morning, but wanted to get some ideas.

Would a fully blown voltage regulator prevent a restart. I'm a bit baffled since even after the battery light came on, and the tach ceased functioning - the truck still drove just fine. When I go to investigate tomorrow, I'll cross the positive on the starter with a screwdriver to see if I get anything. Any other suggestions?

THANX!

I should add that I won't be back on the computer til tomorrow morning - so excuse me in advance for any tardiness in answering any questions posed...

 

I have no clue.
Keep us posted as to what you find.

 

No, I blown regulator wouldn't keep it from starting. You don't even need an alternator to start it.
When you try to start it it sounds like the starter solenoid isn't even clicking. True?
If so, you need to trace out with a meter or test light where the current stops.
It does sound like you might have a bad regulator too, but that's probably unrelated.

 

Thanx. That was my thinking on it, but I've learned to never let myself be certain when it comes to Rover Electrics!

True - the solenoid would not even click.

I tried shorting the starter and had no luck. So I was starting to think it was just the starter again, but that would not explain the battery light, no tach, and voltage spikes. Then it dawned on me - immobiliser? Sure enough, I went to lock and unlock the doors with the key and nothing. I then got in and manually locked the drivers door to see if the other door locks would activate. Nothing. On a whim, I tried starting it with the drivers door locked and unlocked. Wouldn't ya know it. The damn thing started.

I live about 15 miles away from where the truck was parked, but since I'd put a drain on the battery with all my testing - I wasn't comfortable taking the chance of driving home and having the battery run dry on me since I've still got the battery light on with no tach - I'm assuming I've got zero output from the alternator. So I thought it best to drop the battery off at the local auto parts store for a full charging and am now sitting at a coffee shop waiting for an hour for it to charge.

As soon as I get it home, I'll start trying to sort out what I now am thinking is a problem in the alarm circuit. I've ZERO knowledge of the factory alarm/immobiliser on these things - so I'll be reading up over the next hour. Any suggestions as to where the likely problem areas are (or even better - how to just disable the damn thing if possible? I seem to remember reading something about attaching a ground wire to some part of the system found in the passenger floorwell?)

Thanx! (The whole thing had me baffled all night thinking about it)

 

This may help you:
http://forums.lr4x4.com/index.php?showtopic=86

 

Thanx again Tom. Mine is a '95. I noticed the writeup specified '96-98? Do you know if there is a spider unit in the '95 as well? I've removed the warped dash to replace it with a new one that I picked up for the ridiculous price of $20, so I've been deep into the dash area and don't recall seeing that little black box. The symptoms certainly seem to match though!

 

suede the battery sounds like it got fried by the alternator when it finally went completely caput.get a fresh battery and alternator and im sure it will fire right up,and next time dont wait so long to replace it voltage spikes are bad

 

I had something similar happen to my 98. It was like it when I bought it. I had the alternator rebuilt, tested...everything was fine. I had the dash apart (I could see others had been in there as well before me), and checked relays etc. What it turned out to be is the serpentine belt was routed the wrong way. Sounds too easy to be true, but routed incorrectly it will charge ok until ya get up to high speeds. Then the belt will begin to slip, but still spin - - just not enough. Tooling around town it would was usually ok. At highway speed, when conditions were right, the belt would begin slipping, and (I assume), voltage would drop and the tach would drop, sometimes jump around like nuts, dash lights would go out, the ECM light would come on, all the things you mentioned. On long enough journeys the battery would drain to the point it wouldn't start. However, let's say I pulled into town and by the time I got home, that little bit of lower speed driving would let the battery charge to the point where it would start again next time. So it took a bit to figure out. I don't know if any drivetrain relays would chatter though. On top of that, my vehicle did not have a routing diagram on it so no way to verify. Someone here clued me in on the routing and I put a new belt on it and routed it properly and problem fixed. BTW, my battery was shot anyway from the continued discharging. I mean, it worked, but barely at that point.

Now, my vehicle didn't seem to have increased voltage, so maybe it's not related to your condition. I'd check your belt routing, check the battery, check your starter solonoid (could have multiple problems). Might be a good idea to take your alternator to a alternator shop for a comprehensive test (usually free) just to rule it out. It might also be the Spider Relay issue as well but this gives you something else to look at. Please keep us up to date on what you find.

 

Sorry, missed the year. No, the '95 doesn't have the spider, luckily.
If the lights work, and heater blower works normally, but the starter solenoid won't operate, it's not likely the battery.
That's not to say that the battery may not also be weak, but the solenoid should at least click.
It sounds like you have several things going on, but it doesn't sound like the battery or starter to me, based on the fact you've managed to get it started since the problem began.

 

Ok guys, thanx for the suggestions. I returned home about an hour ago and I'll update with what I've learned thus far.

1: The battery tested out fine at the auto parts store and accepted a full charge with no issues. It's about 6 months old and is showing it's still quite healthy.

2: The power door locks are still not operational, but I was able to determine that it wasn't the door lock position that changed the start/no start state, but turned out to be if the door was opened or closed. When I was trying to get it started yesterday, I'd leave the door open each time I'd get in and out - so it never occured to me that would make any difference until I started thinking the alarm system was at issue. When I came out of the auto parts store and reinstalled the battery - I was again getting no response. I tried cycling the door lock a couple times, but to no avail. It then started to drizzle, so I shut the door while I pondered. The next time I turned the key - she started right up. So I shut her off, opened the door, and tried to start but no start. Reclosed the door, and she started right back up. I left the door open and held my hand on the doorlight trigger button and she started right up. So I'm now pretty certain that we're on the right path in assuming a problem with the alarm system.

I currently have my motorcycle taken apart in the garage and can't pull in the disco out of the rain - so I've decided to table doing anything else until after the alternator arrives on saturday. I'll update with my findings after I've installed the new alternator and traced down the power door problem that's likely causing a hiccup in the alarm circuit somewhere. I'm thinking that the voltage spikes probably blew a fuse, or fried a board somewhere along the line. We shall see - but at least she can now start reliably, and battery & starter have been eliminated as potential culprits.

THANX AGAIN!