Parked the 318 and now it died while driving

[pjoll84]

Well, this is a new one… my new moho has been starting just fine until today.

318 only clicked and then nothing… battery showed full on the charger. Boosted it with my truck and it fired up after.

Drove around a bit to charge the the motorhome (which is what I thought it needed) made the mistake of driving on to the highway and after I put on the windshield wipers, the lights and heater… it started to sputter and then died (which is where I am sitting right now).

Won’t even click or turn over… at one point the flashers didn’t have enough to power to turn on… only the relay and the suddenly they started flashing (lots of angry honking before that)

Anyway, this hasn’t been an issue. It has always fired right up, a few days ago I wired in a toggle switch for the fog lights… it may be a coincidence but seems like it doesn’t like my wiring job lol.

Is this classic dead battery? What do I start hunting down?

Appreciate the help, we are supposed to go camping in a couple of weeks so my wife is not going to like seeing a tow truck in the driveway ‍

 

[Charles Cook]

How old is the battery? If it’s a bad battery you should install a new one and once you get it running, disconnect the positive side and see if it continues to run. That will eliminate the alternator. Don’t let the positive cable touch anything while you’re doing this.

 

[twecomm]

Sounds likely it's the battery. How old is it ? They can be fine one minute and next time nothing. I've had this experience on many cars over the years.
Another possible issue might be one of the diodes in the alternator could be defective dragging the battery down. With battery DISCONNECTED, you might try removing the large wire on the large stud of the alternator, insulate it so it can't short to chassis or engine, and re-connect the battery and try charging the battery with a battery charger and see if it holds a charge. That heavy wire of the alternator is effectively connected directly to battery +.

 

[pjoll84]

vehicle is new to me… I think it’s date stamped 2020… just sputtered and died. Not even the solenoid would click. Barely enough for the hazards to flash.

I’m hoping it’s just the battery and my fog light wiring killed a tired battery

 

[ruffcut]

As soon as I read the OP, I went with the battery as well. It will show correct voltage on the charger, but have no amperage. Jump start and will run off the alternator.
You need a new battery!

 

[pjoll84]

As soon as I read the OP, I went with the battery as well. It will show correct voltage on the charger, but have no amperage. Jump start and will run off the alternator.
You need a new battery!

Appreciate it. When I put a voltmeter to it, it reads 13.56 but won’t even engage the solenoid. Only jump starting will get it going.

After an expensive tow home, I’ve jump started it again and it’s reading 14.82 on the voltmeter… its seems to be charging… but not enough ccs to start it on its own. Does that make sense? Or is that what you’re saying?

Did it die because all those systems were being run by the alternator alone then?

 

[Don Frelier]

13.56 is very high.
The cables and connections are good?

 

[pjoll84]

13.56 is very high.
The cables and connections are good?

I replaced all the battery cables and cleaned up every connection when I bought it. Like I said, it started up like a hot damn every time until today where it turned over VERY SLOW and then died. I threw on the charger and it read 90%. After some time, I tried the key, (and the charger connected) I’d get the solenoid clicking like crazy but not engaging the bendix. Then when I jump started it, it would light off fine.

 

[RemCharger]

It's weird but as a shop, people will tell you to put starters and alternators in their cars all day long. They hate the idea of buying a battery so much that the thought won't cross their mind.
It's a pattern I'm trying to figure out

 

[pjoll84]

lol sorry, I know yall are screaming it’s the battery and I appreciate it!
I hooked up the multimeter and watched it go from 13.56 to 4.56 when I turned the ignition

 

[Fran Blacker]

How old is the battery? If it’s a bad battery you should install a new one and once you get it running, disconnect the positive side and see if it continues to run. That will eliminate the alternator. Don’t let the positive cable touch anything while you’re doing this.

Been told not to disconnect battery with engine running, it would screw altenator up? T or F

 

[RemCharger]

Been told not to disconnect battery with engine running, it would screw altenator up? T or F

Likely not but it's a gamble you take.
Save that trick for emergencies

 

[Charles Cook]

Been told not to disconnect battery with engine running, it would screw altenator up? T or F

When I do it, I turn the engine off before I reconnect.

 

[sam dupont]

If your alternator is working, the armature bearing cap on the rear of the alternator is magnetic.

 

[pjoll84]

If your alternator is working, the armature bearing cap on the rear of the alternator is magnetic.


View attachment 1680398

Ok, I’ll see if some metal sticks. Does it have to be running for this to be magnetized? (Honest question)

 

[pjoll84]

Just picked up a used battery, 4 months old and tested for cheap. Fired right up on the first crank. Voltmeter says 14.9-15.03 when running.

Hopefully this helps others. Solid charge and volts but zero amp, thanks everyone (and @ruffcut) let’s hope I don’t have a parasitic draw somewhere lol ugggh

 

[72RoadrunnerGTX]

Been told not to disconnect battery with engine running, it would screw altenator up? T or F

There is a very high risk of causing severe damage to electrical system components by suddenly removing the battery load while the charging system is in operation on an alternator-based charging system. Never disconnect the battery while running, especially with more modern computer integrated electrical systems. Spikes of over-voltage and over-current can result. There are far safer ways to diagnose alternator performance than disconnecting the battery while running. One of the first things I was taught as a young technician decades ago. That myth dates back to generator-based 12 volt changing systems.

 

[kiwigtx]

Just picked up a used battery, 4 months old and tested for cheap. Fired right up on the first crank. Voltmeter says 14.9-15.03 when running.

Hopefully this helps others. Solid charge and volts but zero amp, thanks everyone (and @ruffcut) let’s hope I don’t have a parasitic draw somewhere lol ugggh

First of all, glad you got up and running again.

Second - I am going to suggest that you look into the starter motor. Something about draining the battery while turning the key makes me wonder if the solenoid in the starter, or indeed the starter itself is all coked up with carbon dust.

This happens. It happened on two of my daily driver cars (one was my wife's car) - installed brand new starter motors and the problem has never returned. The battery in one car went flat over about 3 days while sitting. The other car just drained hard while driving, and overnight failed to re-start.

Yes, it could also be that you had a bad battery that was well below its useful life span...and the cranking was enough to finish it off for good. A cheap battery load tester will not be accurate and can say the battery is OK, when in fact it might not be.

 

[Don Frelier]

Voltmeter says 14.9-15.03 when running.

Again your numbers are high.
Either your meter reads high or it's overcharging which may have been the reason your battery was wiped.
You may still have a problem here.

 

[pjoll84]

Again your numbers are high.
Either your meter reads high or it's overcharging which may have been the reason your battery was wiped.
You may still have a problem here.

I was thinking this too… shop manual says 15.03 is ok but I need to test it with the ballast resistor and not battery directly. If it fails that test, would this suggest my voltage regulator is hooped or somethings wrong with the alternator.

I’ll take a look at the starter @kiwigtx, I certainly want to make sure this doesn’t happen on our trip… I had read somewhere that if you hook up the multimeter and turn the ignition, and you see such a massive drop, it confirms the battery is toast (here’s hoping that’s it lol)