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Lick my balls
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Discussion Starter #1
I replaced the alternator with a 3G about 1 year ago and I soldered the connections. Several months ago, I installed an after market volt meter. Now to the issue.

When I start up the truck the meter reads 14 volts and will drop to about 13 1/2 volts maybe less, when I turn on the lights and heater. I would have expected the volts to stay at 14 with the alt. upgrade but whatever.

Rescently, I've noticed that my volt meter will stay at 14 volts with everything on but only sometimes. The battery is about 4 years old and the battery check thingy is green on my battery, yet there have been times where my truck barely started. I don't know what to check, besides poor connections to solve the volt reading problem. Is there something I can check, or should I chalk this up to a faulty alt? I should add that when I installed the volt meter, I also cleaned the battery terminals and installed new battery cable terminals.

I will have to buy a new volt meter since both my cheapo meter is not reading correctly and my expensive one drowned one day in coolant when a hose burst.

As soon as I can get my dad out of his garage, or I have a warm day I will be looking into it. Hopefully someone can give some direction here in the mean time.
 

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green ones make me horny
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I would check the battery with a voltmeter. Check it not on and see what it is, start it and see what it is, and then while you are checking it have someone turn everything on. The Voltage should drop and then come back up right away. if not your battery is not getting charged. take it to get tested along with the alt.
 

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Lick my balls
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Discussion Starter #3
I would check the battery with a voltmeter. Check it not on and see what it is, start it and see what it is, and then while you are checking it have someone turn everything on. The Voltage should drop and then come back up right away. if not your battery is not getting charged. take it to get tested along with the alt.
That's what I was thinking too. I used the meter I had and although it is giving me a false reading, it shows an increase in voltage when it is running and a drop when everything is turned on and in this instance, neither the meter in the truck or the one I was using showed a return to 14 volts after everything is turned on inside the truck.
 

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Lick my balls
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Discussion Starter #4
I believe the battery is non serviceable, but I did notice what appeared to be a small amount of acid maybe about 2" in diameter at either end near the caps.

I thought if that hole you looked into showed a green light or a green colour, that your battery was ok.

I will be driving by a garage in the next couple of days, I will see if I can get them to check the bat and alt for free, otherwise, I will be putting a new voltmeter on my parts account and doing it myself soon.
I noticed today also, that my starter wrap has come off the starter and is just hanging there. I suppose my headers may have cooked the starter which is only a couple of years old and my alt/bat may be a non issue after all.
 

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Zombie Hunter
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You probably run into the same problem i do Walt.

A starter turning a cold motor is a huge draw on the battery. Especially when we get into single or negative digits.

being that your in BC, it might not be a bad idea to look into a block heater.

and just so you know, Advanced Auto (i don't know if you have them up there) can check your charging system without physically removing anything from the truck
 

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green ones make me horny
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You probably run into the same problem i do Walt.

A starter turning a cold motor is a huge draw on the battery. Especially when we get into single or negative digits.

being that your in BC, it might not be a bad idea to look into a block heater.

and just so you know, Advanced Auto (i don't know if you have them up there) can check your charging system without physically removing anything from the truck
Shit it hits 55 here and im wanting a bloc heater....i keed i keed.
 

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Lick my balls
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Discussion Starter #7
You probably run into the same problem i do Walt.

A starter turning a cold motor is a huge draw on the battery. Especially when we get into single or negative digits.

being that your in BC, it might not be a bad idea to look into a block heater.

and just so you know, Advanced Auto (i don't know if you have them up there) can check your charging system without physically removing anything from the truck
Actually Rob, I have the problem of my motor turning over when it is at operating temp. Which makes me think maybe the starter and since I don't have a propperly working meter, I can't check the battery. But mind you, I do notice the after market gage is reading as low as 8 volts, IIRC.

Also where I live, it is very mild. today it got as cold as 32*F but the average for the last week has been about 42*F

I may make it sound colder than it is because I hate cold, it makes me break out in these tiny little bumps. I try to see the doctor, but every time I go into the office the little bumps go away.:toothless

EDIT: I'm not sure if I have an Advance Auto up here. I'm sure I will find someone to help me out.
 

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OUT OF BUSINESS / M.I.A.
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I do notice the after market gage is reading as low as 8 volts.
You would notice that, not sure if the truck would even run at that point. sounds like a bad gauge or connection to it.


Dash voltage is not just the alt / battery combo. It also brings in the supply wires, which could add resistance to the system. Plus the more stuff you have running on that supply line will increase the resistance even more.

1) Check the Battery voltage after a few hours of sitting. It should be ~12.6 volts, any lower and you have......
A) electrical drain in the system.
B) Bad battery.

2) Check the vehicle voltage at the battery with the engine running all that stuff running.
A) If it's ~14.6 you have some resistance in the supply wires to the dash.
B) if it's lower than 14 you have some alternator problems.








My 1986 Bronco with stock dash harness will drop to 12.5 volts with everything running.
BUT I have 14.6 at the battery, so my alternator is fine.
However I have been adding relays for lights, and larger supply wires every time I do something in the dash.
 

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Lick my balls
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Discussion Starter #10
You would notice that, not sure if the truck would even run at that point. sounds like a bad gauge or connection to it.


Dash voltage is not just the alt / battery combo. It also brings in the supply wires, which could add resistance to the system. Plus the more stuff you have running on that supply line will increase the resistance even more.

1) Check the Battery voltage after a few hours of sitting. It should be ~12.6 volts, any lower and you have......
A) electrical drain in the system.
B) Bad battery.

2) Check the vehicle voltage at the battery with the engine running all that stuff running.
A) If it's ~14.6 you have some resistance in the supply wires to the dash.
B) if it's lower than 14 you have some alternator problems.








My 1986 Bronco with stock dash harness will drop to 12.5 volts with everything running.
BUT I have 14.6 at the battery, so my alternator is fine.
However I have been adding relays for lights, and larger supply wires every time I do something in the dash.
Thanks for posting Ryan, I was hoping you would.

You are right, there is a drop where I spliced my meter into. It was the closest to the battery voltage I could find with about .25 to .5 volt drop, can't remember for sure now.

Anyways, I got a new multi meter and after 3 hours of sitting, the battery read 12.72 volts.

With the engine running and everything on, the reading was 14.37 volts and after 3 minutes with everything on, it went up to 14.88 volts.

So it would seem my battery and my alternator is fine.

That leaves me to suspect my starter. Oh and the volts do drop to as low as 8 volts while cranking over the motor.
I will be looking at the starter when I do my oil change tomorrow or the next day.
 

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Zombie Hunter
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voltage is kind of a carrier for current (amps). When you start consuming current (amps), the carrier, voltage, will drop.

There should be a current load on the starter, it's usually on the piece of paper that comes with the starter that everyone wipes grease on and throws out without even looking at it. It should indicate to you how much voltage and current should be drawn to turn the starter over with a load.
 

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I have experienced a new starter cable go bad because it was too close to the exhaust manifold and the heat melted the insulation and corrosion set in on the conductor and caused too much resistance. It wasn't obvious to see visually and a continuity check showed 0 ohms on the cable, but when I tried to start it the current flowing through the damaged cable caused heat and increased resistance. Also, did you check the starter relay and its connections?
 

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Lick my balls
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Discussion Starter #13
voltage is kind of a carrier for current (amps). When you start consuming current (amps), the carrier, voltage, will drop.

There should be a current load on the starter, it's usually on the piece of paper that comes with the starter that everyone wipes grease on and throws out without even looking at it. It should indicate to you how much voltage and current should be drawn to turn the starter over with a load.
I can call the parts store I got the starter from to find out what the load should be, but I don't know how to check that. I will see if my Hanes manual tells me how.
I have experienced a new starter cable go bad because it was too close to the exhaust manifold and the heat melted the insulation and corrosion set in on the conductor and caused too much resistance. It wasn't obvious to see visually and a continuity check showed 0 ohms on the cable, but when I tried to start it the current flowing through the damaged cable caused heat and increased resistance. Also, did you check the starter relay and its connections?
How did you determine the cable was at fault? Did you just replace it and found out that way, or did you test it somehow?
I have not checked the starter connections yet. The relay connections are good, and I'm not sure what to check on the starter relay. The starter engages so it works, right?
 

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It's all about resistance (see last paragraph for an explanation). My starter cable was visibly burnt/corroded near the exhause manifold so it induced excessive resistance and reduced current flow to the starter. If the starter relay has carbon or corrosion buildup on the studs or internally it may be introducing excessive resistance when you try and start. You can bypass the starter relay by turning your ignition to run and then start the engine by laying an old screwdriver across the 2 large lugs on the starter relay; it will throw some spark and make a pop but as long as your handle is plastic or rubber you won't get hurt, do not touch the 2 smaller connections on the relay with the screwdriver. If it starts strong when bypassed like this then get a new relay (or keep a screwdriver in the glove box to start it everytime...not).

The more resistance in a circuit the less the current there is. There is a formula called Ohm's law which simply put states that voltage=current x resistance. It can also be figured as current = voltage/resitance or resistance = voltage/current.
 

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Lick my balls
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Discussion Starter #15
It's all about resistance (see last paragraph for an explanation). My starter cable was visibly burnt/corroded near the exhause manifold so it induced excessive resistance and reduced current flow to the starter. If the starter relay has carbon or corrosion buildup on the studs or internally it may be introducing excessive resistance when you try and start. You can bypass the starter relay by turning your ignition to run and then start the engine by laying an old screwdriver across the 2 large lugs on the starter relay; it will throw some spark and make a pop but as long as your handle is plastic or rubber you won't get hurt, do not touch the 2 smaller connections on the relay with the screwdriver. If it starts strong when bypassed like this then get a new relay (or keep a screwdriver in the glove box to start it everytime...not).

The more resistance in a circuit the less the current there is. There is a formula called Ohm's law which simply put states that voltage=current x resistance. It can also be figured as current = voltage/resitance or resistance = voltage/current.
I knew that. I feel dumb for asking now.

I need to find out the specs for my starter.
So, once I know how much current the starter should be drawing, I just hook up my multi meter to the battery and read the amps, or the drop in amps at the battery? I don't know.
 

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UPDATED
Youre probably not going to be able to read the amps in the circuit with a standard multi-meter, they are likely too high. You could read the total resistance of the circuit (and then divide the the battery voltage by the resistance) but you would have to disconnect the batter and send a 12v start command to the relay to measure its internal resistance...figure that one out. You could measure the voltage drop across each item in the circuit while starting the engine; if any component showed that it was dropping voltage across it that would indicate that there is resistance and current reduction therefore the part is bad. Only the starter should be dropping any significant voltage. Following the diagram below, connect your volt meter to each component where each set of matched letters indicates (red connector to the red A and black to black) and then turn over the engine with the key but pull the coil wire so it will not start. Each location will show 0 volts while not trying to start the engine but if any one location shows a the voltage increase when turning the engine over then it has resistance and it should be replaced.

Click here for the diagram

Or you could throw the screwdriver across the relay and prove or disprove that the relay is the problem and then visibly inspect the starter cable or remove it and check it for 0 ohms of resistance (0 is good, 5 or greater is likely bad). also, make sure your ohm meter is zeroed out before starting.
 

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Lick my balls
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Discussion Starter #17
Cool, thanks. I will try that. I will just have to read that a few more times to clear up some of that Greek lingo.
 

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I will turn you into an electrical engineer before you know it. It's all pretty simple when you sit back and look at it.
 

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Zombie Hunter
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UPDATED
Youre probably not going to be able to read the amps in the circuit with a standard multi-meter, they are likely too high. You could read the total resistance of the circuit (and then divide the the battery voltage by the resistance)
Ohm's Law! w00t!

Remember that pie chart i had as my avatar Walt? V= I x R. Manipulated into I= V/R

I should of stated that. The amp draw on a starter is well beyond that of a multi meter you bought at the hardware store, if you physically want to measure it, you'll have to manipulate other data to get your answer.

Or you could throw the screwdriver across the relay and prove or disprove that the relay is the problem and then visibly inspect the starter cable or remove it and check it for 0 ohms of resistance (0 is good, 5 or greater is likely bad). also, make sure your ohm meter is zeroed out before starting.
You're definitely old skool, us new kids like them digital multimeters. The only thing i have to do before checking resistance is touch my leads together to prove the leads have no resistance.

I only know of two guys that still use analog meters, and they've been in the business for years. They also yell at you if you use their meters to make sure that you're using the right lead in the right spot!
 

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When I get to the point where I need a multimeter I am so depressed that I don't care if it's an analog, digital or .45 auto.

I have been in the electronics field since 1985 (we used to walk to and from school in our bare feet, uphill both ways). I have learned that a cheap analog meter is fine for automotive use and you can take it on a rough trail with you and worry about it betting broken or lost.
 
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