Charging System Problems

happilymarried · Mar 25, 2010

Okay, I've searched through the forums, and haven't really found anything that sounds like my exact problem.

I bought my 84 BII about a month ago with a new battery in it. It takes a bit of time to start w/ the oil-fouled plugs from my leaky valve-seals that I haven't been able to replace yet, but I had been noticing the speed of the crank slowing the past couple weeks. This morning it slowed to a halt and wouldn't start. Jumped it and it fired right up though. Barely started on its own and drove home tonight with lights on (not flickering or dimming or anything).

My question is basically: am I correct in assuming my alternator is fine but my charging system is not actually charging the battery, leaving me essentially only so many starts before I've worn down the battery and need to charge it?

The wiring throughout the truck is definitely old and has been messed with. I have found several places where the insulation is missing around the wires (actually, saw that on the back of the alternator this morning, but haven't had time to explore it thoroughly), and there are a few things that just aren't even hooked up to anything. I haven't seen a battery light (or any warning lights, for that matter), so I'm guessing that is either not hooked up or burnt out. Would these be creating a constant drain on the battery? My only doubt about that is that it took a whole month to drain the battery and it was very gradual. I had a short develop on another truck a while ago and it didn't take a week to suck the life out of that battery.

I don't have a ton of time to work on it in the next few days so it would be awesome if someone could point me in the right direction so I could get it fixed quickly (as if "fixed quickly" and "electrical problems" ever go together in the same sentence). Thanks!

srteach · Mar 25, 2010

happilymarried said:
Okay, I've searched through the forums, and haven't really found anything that sounds like my exact problem.

I bought my 84 BII about a month ago with a new battery in it. It takes a bit of time to start w/ the oil-fouled plugs from my leaky valve-seals that I haven't been able to replace yet, but I had been noticing the speed of the crank slowing the past couple weeks. This morning it slowed to a halt and wouldn't start. Jumped it and it fired right up though. Barely started on its own and drove home tonight with lights on (not flickering or dimming or anything).

My question is basically: am I correct in assuming my alternator is fine but my charging system is not actually charging the battery, leaving me essentially only so many starts before I've worn down the battery and need to charge it?

The wiring throughout the truck is definitely old and has been messed with. I have found several places where the insulation is missing around the wires (actually, saw that on the back of the alternator this morning, but haven't had time to explore it thoroughly), and there are a few things that just aren't even hooked up to anything. I haven't seen a battery light (or any warning lights, for that matter), so I'm guessing that is either not hooked up or burnt out. Would these be creating a constant drain on the battery? My only doubt about that is that it took a whole month to drain the battery and it was very gradual. I had a short develop on another truck a while ago and it didn't take a week to suck the life out of that battery.

I don't have a ton of time to work on it in the next few days so it would be awesome if someone could point me in the right direction so I could get it fixed quickly (as if "fixed quickly" and "electrical problems" ever go together in the same sentence). Thanks!

If you can drive more than 15 miles, the alternator is fine.
The system works like this, generally:

Stored energy in the battery is used to turn the starter and supply initial electric until the engine / alternator is spinning
When the engine / alternator is spinning (and working properly) engine electric is supplied by alternator
If the alternator is not working properly, the battery is used to make up the difference or absorb over output from the alternator. Over output can burn up a battery as quickly as repeated deep drain cycling.

From your above statement, the battery is bad.
If you take the truck to a mechanic / parts store, they can test battery, alternator and starting system all at once. If they can't, go elsewhere.

happilymarried · Mar 25, 2010

Okay, that's kinda' what I thought. Would a new battery go bad so quickly? By bad do you mean it just needs a charge or it's defective and I need to replace it? I'll try to swing by a place and have them test some stuff for me today so I can have more information for you guys (unless it's as simple as a bad battery, of course).

Thanks for the input and I'll keep you guys posted.

WTF · Mar 25, 2010

Here's a simple way to test it:
1-start it up and make sure it's idling fine
2-disconnect the battery ground while it's running
3-if your truck dies or the RPMs drop the alternator is going/gone
4-otherwise it's wiring or the battery

There is a tech page on this stuff too. Good luck!! :icon_cheers:

country0001 · Mar 25, 2010

WTF said:
There is a tech page on this stuff too. Good luck!!

AMEN. We often forget about the tech pages. Others have been gracious enough to take note of their expieriences and jot it down for the rest of us.

BeefStew42791 · Mar 25, 2010

look for shorts as well, some may not show up when the truck is off, but show up when your driving which will rob the alternator of power. Thats exactly what my problem was, and the culprit ended up being in uninsulated wiring that was making contact with who knows what.

As was said though it may be as simple as your battery being shorted out (bad). To test if your battery will accept a charge either charge it with a plug-in battery charger or hook up jumper cables to another running vehicle while leaving your truck off. This way shouldn't take more then 15 minutes to a half hour to charge your battery if it will accept (hold) a charge at all.

As a side point though, its pretty much common knowledge that disconnecting the negative battery cable while your vehicle is running can fry a LOT of things (including the truck's computer, alternator, a butt load of fuses, etc.) so thats something that I'd highly discourage.

trail B2 · Mar 25, 2010

If you think it could be a short or drain disconnect the battery at night hook it back up in the morning see if that helps.

If your thinking its the battery have it tested or swap batteries with another running vehicle is nice.Ive had a new battery quit before got charged $80 for the news.Don't forget if the battery runs out of juice and freezes it can make it short out.

If your thinking its the alternator check the voltage after it starts should be right around 14 volts at the battery.You can test these at the parts house too if you want to be more thorough.Also if you disconnect the battery while its running it will spike the voltage.

kimcrwbr1 · Mar 26, 2010

It could also be the starter going bad not turning it fast enough to start easily and drawing too much power for the alternator to recharge the battery. classic starter symptoms just went thru it especially if you do alot of short trips if you still have the computer working do not disconnect the neg on the batt while it is running you can damage the computer even for a few seconds, use the test procedures in the tech library to test the charging system. It takes me about 5 mins to pull the starter have it tested it can ruin the charging system. With a fully charged battery check the voltage ignition off start the engine wait till the voltage stabilizes it should not be over two volts from batt voltage at around 2,000 rpm then turn the lights and heater on it should not be less than 0.5 volts. If it fails that test in the charging system section it will show you how to determine if it is the alternator, regulator or battery. Mine had a connector not pushed all the way in on the regulator my lights no longer surge from a idle at a light when I give it gas so check all the connectors and wires also before you buy anything. It is cost effective to change the regulator with the alternator and dont assume it is good assure it is working properly after you change any parts as any one can ruin the others in a short time.

kimcrwbr1 · Mar 26, 2010

I also had a slow drain on my battery and found out the EEC relay for the computer was stuck on do you hear a click on the passenger sidepanel when you turn the key on and then a few seconds after you turn the key off. The contacts were welded closed and I just grabbed one one day at the bone yard one day looking for stuff (I like to do that) and never had that problem again before I did the duraspark. New valve guide seals and the duraspark conversion are in your future if you want to bring the animal out get rid of all that emission crap that is if you dont have to pass emissions.

happilymarried · Mar 26, 2010

Well, I took it to the auto parts store yesterday for some testing and the battery tested bad. It did appear to be getting a charge though (right at about 14 idling and up to about 14.4 when I gave it some gas), so I swapped it out for a new battery and I'm hoping that fixes it. I'm a little skeptical though, so I'll definitely be listening for it to start cranking slower (it cranks super-fast with the fresh battery though, so I don't think I have a starter issue).

I am about to order the valve seals and a new set of plugs to get it starting quicker (unless anyone has a good tip for cleaning the month-old platinum plugs that are now all gummed up with burnt oil). By "duraspark conversion" do you mean upgrading to some fancy plugs, or is that the aftermarket ignition box set-up? Also, does anyone have any tips for the old-school rope in the plug hole trick for changing out the valve seals since I don't have easy access to compressed air? I just want to make sure I do that right and don't drop a valve.

Thanks for all the help guys...I really appreciate it!

Robert_1967 · Mar 26, 2010

I never heard of the "rope in the plug hole trick" before, and the "duraspark conversion" can be found here: http://www.therangerstation.com/tech_library/DurasparkII.html

Robert

kimcrwbr1 · Mar 26, 2010

I just ground a tip from my compression tester the size of the plugs put each cylinder on TDC and put 20 lbs pressure to hold the valves up. put the pistons all the way up so you dont accidentallty drop one into the cyl. I heard of the rope thing just stuff a few feet of nylon rope into the cylinderand turn the crank until it stops I would guess the more the better so it holds the valves shut then turn it back enough to pull the rope out. If your doing the air dont compress the spring all the way until you pop the keepers loose so they dont fly away I got real lucky almost lost a couple. Just turn the crank back enough to pull the rope out I dont know how much it matters but turn the crank clockwise just in case. With the air i used a long skinny screwdriver to find top of stroke until it started to drop a little then back a little just dont bind the screwdriver turn it slow and pull it out when you feel it push up. Use the tech library it explains what you need part numbers and wiring diagram it costs around 130 dollars for the dizzy,cap,rotor,adaptor and module you can get the harness at the bone yard if your lucky the only wires you need are the water temp and oil pressure sensors and alternator wires everything else goes by by harness vacuum solenoids the only vacuum you need is for the distributor. you can use your carb with a metering block or put a non feedback carb from an earlier year the ignition is easy but the carb can be tricky.

chazzone · Mar 27, 2010

You might want to pick up a cheap air tank, instead of the rope.

You could even use a hand pump to replace the air you lose in each cylinder.

Been there, done that.

Just a thought...

Charging System Problems

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