Weird Electrical no power, then power

[Rileysowner]

I have has a weird problem and ideas on a fix would be appreciated. I will say everything that happened even if not related. Monday I made a quick stop 1-2 minutes and when I tried to restart the van it wouldn't stay running sputtered and the start was sluggish. I tried 2 times, then waited a minute or two and it started fine, and continued to start fine.

Today my wife pulled into our campsite, turned off the van and I suggested she move it further off the road. She tried to start it and it was like it had no power. A module under the dash made a clicking/vibrating sort of noise (If I disconnect that module there is no power but I have no idea what it is), door locks would not work. It was like a dead battery. I figured something might be draining the battery so I disconnected it while I thought of what it could be. Later, maybe 15 minutes, I reconnected the battery and it started fine. Lots of juice and a good charge according to the volt gauge.

Any idea what this could be? I am camping right now, and using the free wifi at McD's so I hope someone can make a suggestion I can look into while camping. Since it is intermittent and we have the car with us for driving around I won't need the van until I need to tow the trailer home, but I am hoping a fix will be easy and inexpensive.

I am off to the camp site again. I will check back tomorrow.

[1Gary]

Suggest you take a hard look at your grounds.

[Rileysowner]

That is what I was thinking. I had a similar problem once when I didn't tighten the battery connector firmly enough. I'm happy for corroboration on my thinking on this.

[kentek]

I thought I might post here to see what happened with this issue and to say that I have a similar problem.
So far I have replaced the battery, alternator twice, and then I was told by a service station who spent well over an hour on it that it was my computer not getting the signal as per extensive testing and thankfully $50.00 charge, but alas I still still have the same problem, sometimes it works and sometimes it doesn't, we boost it and everything is fine, drive for a distance of couple hours and bam there we go again... We've tried everything we can think of and still can't figure it out? The alternator is 1 wire plug and live positive wire.. battery is new $70.00 10 year warranty,, Alternator is twice new 1 yr warranty.. Computer is number two used $50.00.. recoded by dealer.. $75.00...

our next move was to try and run a new line from the plug on the alternator to the computer but not sure where to run it to..
or/Then strip the harness and trace the feed UGh! so tight working in there!

Any suggestions would be great?

[MountainManJoe]

Can you please fully explain your symptoms, kentek?

[kentek]

just as I said from time to time it will not charge. Battery Light comes on, power reduces till can't run anymore then we boost it and sometimes it's good and other times No... it's like a dead short as they so call it,, definitely seems like a short or could be a bad ground I guess but we're talking Alternator Here so what is not getting the ground then? can anyone be more specific? it's a maze under there..

Like I said new battery,alternator, then told it was the computer, but the problem persists as it was, and has not changed...?
Pretty sure it's gonna be in the harness somewhere????

[kentek]

when it's good charge is 'A' OK but when it drops charge indicator drops too, so we know when it's happening

[astroturf]

Sounds like your battery is not charging.

[MountainManJoe]

Do you have a voltmeter or multimeter? If not, get one because they are dirt cheap and immensely useful tools.

Post your voltages at the following points with the engine running:
- Battery
- Starter motor
- Alternator

[kentek]

and I will get two voltages for each of those locations since what I'll have to do is activate the Fault because when the volatge is good it's pushing 14+ but when it dips it will draw down gradually.. You understand that right?

when it's good it's just good but when it's bad it draws down, Like a short! only happens sometimes, I mean I could drive it all day and nothing then suddenly something happens and we get the drop in power then it's only running off of battery power and not charging...

Since it's a single wire Charge I was thinking it may have something to do with the single line from the plug sending the charge signal back to the computer?
I wondered if maybe I snip that wire and route a new one through to the computer but need to know where to attach it. if anyone knows or if you see that being the problem. Right now I have the alternator out for the third, fourth time... Perhaps if I did a continuity test on this wire and wiggled the heck out of the harness till I see it short out. I have half of the harness undone ready to play with the leads and follow collors? ;-)
I have to have this back on the road by Monday my wife works as a traveling aid doing red cross nursing in home for private residents..

[MountainManJoe]

That wire is for your dummy light.

You need to measure, at minimum, the voltage at your alternator while the problem is happening. And I don't mean look at your gauge. Actually measure it.

[astroturf]

Sounds like an open, and not a short to me.

Have you inspected your grounds?

[MountainManJoe]

Jim, if he's going to inspect wires, why would he only check ground? You also need good positive connections to complete a circuit.

[astroturf]

TB I never said only check grounds.

Check your grounding points first, as they are the most likely culprits...

[MountainManJoe]

Out of curiosity, why are grounds the most likely culprits?