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Power drain with new battery, starter and alternator, PLEASE HELP

  • Ignition control module.

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  • Ignition coil

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  • Engine control module

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  • Relay control module

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  • Fuse box or relays?

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  • Wire harness!?!?!

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  • Something else altogether.

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Help! Voltage drain with new everything! 1998 astro

2K views 16 replies 8 participants last post by  rootbeer99 
#1 ·
I have a 1998 4.3 RWD astro van i just purchased. I put a new battery. New alternator. And a new starter on it. My fuses are good. (i didnt replace relays). And i have done a full tune up. (spark plugs. wires. Distributor cap and rotor button). I have not done the engine control module or ignition control module but might need to. I also have a problem with my headlights. Buzzing in fuse box when i turn on brights while lights are off. And when lights are on. The brights dim my light instead of getting brighter. Im replacing relays next. But For some reason i have a power drain. Only when the key is on. I can jump the van and she starts right up. But my voltage drops until it stalls in less than 5 minutes. Any suggestions on what could be draining the power? Ive had her a week and already put over 1000 in repairs. I also checked grounds for alternator and motor grounds. What else could it be????
 
#2 ·
Put a meter on it and pull one fuse at a time until you isolate on what circuit the drain exists on. Then trace the entire circuit to find the fault.
 
#4 ·
As leeann said You need to use an Ammeter to measure the current draw in various places. Eventually you will be able to find out what device or wire is drawing more current than it should, or current for longer periods of time (like maybe all of the time) instead of only when it should. The first place to start is at the fuse block. One fuse at a time replace the fuse with an Ammeter. You may want to fabricate an adapter out of a fuse so you can plug it in, in place of the fuse and the adaptor will have wires going directly to your Ammeter. I suggest you get yourself a good DMM (digital multimeter) which has a current measuring (Ammeter) capability. Most DMMs do have current measuring function, but most of them are limited to 10 Amps. So with the DMM you will be able to check most circuits on your fuse block, but as you can see by the fuse ratings there are several fuses greater than 10 Amps. You will need another way to measure the current in those circuits. A plain old analog Ammeter with 30 Amp full scale should do. Or you may find one of those center zero Ammeters that read -30 0 +30 Amps. Eventually you will find somethinng that draws current all of the time, even though everything in the circuit is supposedly turned off, or something that draws too much current.
 
#5 ·
The shop wont open until monday. So for the weekend im going crazy trying to diagnose the problem without the van at the moment lol. But i do have a battery light out as well. I know the only two major parts it could be is the ignition control module or the Engine control module. ( as far as what i know anyways ) ill find out what they say monday or tuesday and ill hopefully have it fixed. But the battery light could be a power issue also. Im not sure what to do if its not those those control units. Because my battery cable and ground are stable. ( not new. But barely worn and stable. Ill keep you all updated. I appreciate opinions and i cant learn unless i ask.
 
#8 ·
Um, that's what turning the key on does.

You don't have a drain, you have no charging. Either the alternator is bad or it's not hooked up.

Did you disconnect the battery before you replaced the alternator?
Have you traced the wires from alternator to battery and starter?
Have you put a meter on the terminal to see that it's charging at the battery?
 
#9 ·
Ive checked the wiring and it all seems fine. I didnt check with a meter. I did disconnect the battery before taking the alternator out. I read online the battery light out could cause the alternator not to ground properly causing the alternator not to complete a circuit back to the battery. And engine control module tells the ignition control module how much voltage to give the distributor cap. To then distribute the voltage through the wires and plugs. I didnt check either control module . my concern is after i resolve this issue. Will my voltage be at 14 steady. If not it would be making another post. but unfortunately. My van is in the shop. Im getting the inspections. Ill find out tomorrow and then fix the issue. But im still unsure of what i could do in the meantime. With the jump box hooked up i can keep the van running smooth. The second i disconnect the box from the battery it drops voltage to a stall.
 
#10 ·
Mechbob. As far as automotive and electrical classes. Ive been working on cars for 10 years. I am no mechanic for sure. Yet i know enough to do everything except the motor and trans. Everything around the motor i can do. I also use to build computers so i know enough to hand a circuit. Just dont know enough about cars to say that im anything more than a diy home mechanic. I replaced 3 out of 5 parts in the batteries circuit. The only two i havent done are the two that control the power going to the motor. And the battery light of course but thats just a light. It could however stop the flow of electricity to the fuse box. Thus causing the battery not to receive a charge. Im just confused. Definitely not a pro. And just need some advice lol
 
#11 ·
CoffeeBee said:
The second i disconnect the box from the battery it drops voltage to a stall.
This statement alone... SAYS A LOT!
There is NOTHING confusing about this!

The jump box is essentially the same as a battery, but in this case it's acting as a 2nd battery.
Since it works and the main battery doesn't, you have to find out what's wrong with the main battery.

1) Did you try charging it?
2) Does it hold a charge AFTER you disconnect the charger?

You may have issues with the connectors at the battery.

3) What is the voltage of the battery while engine is off?
4) What is the voltage of the battery while engine is running?

5) What is the running voltage at the output terminal of the alternator?
(only important if no charge is reaching battery)

Either the battery is getting charged, or it's not.
Either the battery is able to hold a charge, or it's bad.

You need a charged battery going forward to determine where the problem is.

Every question above is vital!
You must take voltage readings!
Then we can probably start to help.

If you won't answer each.. then it's just a guessing game.

CoffeeBee said:
My van is in the shop... But im still unsure of what i could do in the meantime...
In the meantime?
I'm pretty sure you can't fix it at home if it's in the shop.
 
#12 ·
CoffeeBee said:
Ive checked the wiring and it all seems fine. I didnt check with a meter. ....
Then you didn't check the wiring.

Looks can be deceiving. A clean shiny insulating jacket can have oxidized/corroded/broken/intermittent conductors inside.

I'm not trying to pile on the new guy, just trying to point out something you've missed.
 
#13 ·
The second i get it back from the shop ill make sure i check all wires and grounds with a meter. Hopefully they can resolve my power issue. But im still concerned. New parts but i got the alternator from autozone and ive heard they have problems with the voltage regulator on their alternators. Luckily i got one with a lifetime warranty !
 
#14 ·
Mmusicman. 1. I tried charging it. New battery but i tried after the initial stall. 2. It did not hold a charge. 3. A little over 12 volts. 4. Started and it went from 12 to 10. Then back to twelve and dropped to less than 9 and then stalled.
5. Havent checked with a meter but the moment i get it back from the shop im checking all wiring with a meter. Hopefully they can find the issue today.
 
#15 ·
CoffeeBee said:
2. It did not hold a charge.
You now need to determine if the battery discharged while hooked to a "power-drain" or if it discharged on it's own.
Charge battery, leave it unhooked for a while, and see if it holds a charge and has enough cranking power.

IF the battery is bad.. then replace it. They make "load" testers.
Different test than just voltage. Most auto parts places will test if for you.

Don't leave a new battery hooked up to a vehicle if it has a power-drain, or you will kill and ruin the new battery too.

Take voltage readings on everything, running and off.
 
#16 ·
Fixed the issue. It was the wiring for the alternator. Just the ground plug that went into the back of the alternator. Not the maim power. But the plug. I got it fixed along with a full brake job. I still have a brake light on though. Im not sure what could have caused that. Its been on and i have no brake issues. I did the spark plugs and wires. And I have gotten four new tires also. And to top it off i only have one code getting pulled on a obd 2 meter. Its po340. The camshaft position sensor circuit. Im going to replace the sensor and hope that fixes the issue.
 
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