Battery Dying After Engine Swap

[pontiacgp]

ok ...whatever you say.....I think that I'd rather have a beer with doober than try to explain anything to you...even if I'm buying... :lol:

Whatever kissass! you can't explain anything to me when i've seen this problem with my own experience. It's simple, you have the battery grounded to the frame and or motor, you have the body grounded to the frame, but you have a motor which sits on rubber mounts but is not grounded to anything>>??? It doesn't make sense does it??? Here's another one for you to read,
http://findarticles.com/p/articles/mi_q ... n13640857/

duh....it's the alternator that charges the battery and the alternator is attached to the engine which is grounded directly to the battery....and am I a kissass because I agree with doober or is it because I mention something about buying the beer....lol

 

[jrm81bu]

It's simple, you have the battery grounded to the frame and or motor, you have the body grounded to the frame, but you have a motor which sits on rubber mounts but is not grounded to anything>>???

You just said it yourself. You are saying the motor isn't grounded because its on rubber mounts. That don't matter if the neg cable from the battery is mounted to the engine. You have your pos going to the starter which gets it ground from the block which is grounded directly to the battery. Right there is the loop.

 

[84GP455]

It's simple, you have the battery grounded to the frame and or motor, you have the body grounded to the frame, but you have a motor which sits on rubber mounts but is not grounded to anything>>???

You just said it yourself. You are saying the motor isn't grounded because its on rubber mounts. That don't matter if the neg cable from the battery is mounted to the engine. You have your pos going to the starter which gets it ground from the block which is grounded directly to the battery. Right there is the loop.

yes but what is grounding the motor to the chassis???? That's what completes the loop!

 

[jrm81bu]

It's simple, you have the battery grounded to the frame and or motor, you have the body grounded to the frame, but you have a motor which sits on rubber mounts but is not grounded to anything>>???

You just said it yourself. You are saying the motor isn't grounded because its on rubber mounts. That don't matter if the neg cable from the battery is mounted to the engine. You have your pos going to the starter which gets it ground from the block which is grounded directly to the battery. Right there is the loop.

yes but what is grounding the motor to the chassis???? That's what completes the loop!

No it doesn't not for the charging system. The ony thing you need the chassis ground for is for things that are grounded to the chassis, light, etc.

 

[jrm81bu]

It's simple, you have the battery grounded to the frame and or motor, you have the body grounded to the frame, but you have a motor which sits on rubber mounts but is not grounded to anything>>???

You just said it yourself. You are saying the motor isn't grounded because its on rubber mounts. That don't matter if the neg cable from the battery is mounted to the engine. You have your pos going to the starter which gets it ground from the block which is grounded directly to the battery. Right there is the loop.

yes but what is grounding the motor to the chassis???? That's what completes the loop!

And if you had to have that 10 guage(or smaller) on there to complete the circuit, then the car would neither charge or start without it. And if that wire completes the circuit then you should be able to un hook the main neg cable from the block, and run just the ground strap from the motor to firewall and another small wire from the fender to the battery, and you would be able to start it and have it charge. Do that and hit the key and watch the amperage fry those wires. Hell even the full output from the alternator alone could do damage with a wire that small for a sole ground especially when it has to go through the body too.

 

[84GP455]

I'm not saying that the engine ground is the "main" ground or it's the only ground that you need, i'm saying that you need ALL the grounds, battery, frame, chassis, motor, in order to obtain the best voltage output. Go ahead disconnect your engine ground and see what happens and take a voltage measurement from the battery and it will be less than 14.5 it might be 14 or 13.5 but it will definitely be less than what you started with.

 

[1984CuttySupreme]

I still havn't had a chance to connect the ground strap that's unattached on the firewall. I have to get some bolts that'll fit the hole on the back of the head. Anybody know what size bolt to get? The car was fine until a couple hours ago. My AC hasn't been turning on at all and finally today it popped on and after a while the charge light started glowing. I got home and tried to started it up again and the battery was dead. So the car lasted 2 days after having the battery on a charger overnight. I dont know if it would've been fine had I not ran the AC but it had the battery issue even before we hooked the AC back up so I don't think there is any connection between the two.

Also, where should I look to connect a ground strap on the bottom of the motor? Or is the one near the engine head & firewall enough?

 

[jrm81bu]

I still havn't had a chance to connect the ground strap that's unattached on the firewall. I have to get some bolts that'll fit the hole on the back of the head. Anybody know what size bolt to get? The car was fine until a couple hours ago. My AC hasn't been turning on at all and finally today it popped on and after a while the charge light started glowing. I got home and tried to started it up again and the battery was dead. So the car lasted 2 days after having the battery on a charger overnight. I dont know if it would've been fine had I not ran the AC but it had the battery issue even before we hooked the AC back up so I don't think there is any connection between the two.

Also, where should I look to connect a ground strap on the bottom of the motor? Or is the one near the engine head & firewall enough?

First thing you should do is take that alternator off and havve it tested. A lot of your problems could be traced to electrical systems failing as your battery dies.

 

[jrm81bu]

I'm not saying that the engine ground is the "main" ground or it's the only ground that you need, i'm saying that you need ALL the grounds, battery, frame, chassis, motor, in order to obtain the best voltage output. Go ahead disconnect your engine ground and see what happens and take a voltage measurement from the battery and it will be less than 14.5 it might be 14 or 13.5 but it will definitely be less than what you started with.

The main ground is your negative post, which is attached though the negative cable to your engine block. Which makes the engine block the best grounded metal surface in the entire car, therefore adding a tiny(relative to the 2 or 4 guage cable) wire that has to travel through the body and back to the SAME cable that the engine block is attached to won't give the charging system any possibility(unless you have a problem with the negative cable being corroded inside the insylation) of having a "better" groun that you say it will. The body doesn't even have to be on the car for the charging system to function properly. The ONLY thing that firewall ground can do is provide a better ground for things that are grounded to the body directly. Adding grounds can't hurt but smaller wires CAN'T provide a better ground then larger wires.

Look at it like this. That firewall ground is around 10 guage. What do you think the amperage rating is for it? 20 amps at most. How much does your alternator put out? 60-90 on these cars. That alone makes that obsolete as far as the Functioning of the charging system goes. The neg battery cable handles 100% of the alternators grounding. Again that firewall ground only provides a better ground for things that are grounded through the body BY CONNECTING THE FIREWALL TO THE NEGATIVE CABLE. This is well after the charging system circuit.

 

[Doober]

These guys are saying exactly the same thing I've been trying to say :lol:

Like I said before, a good body ground is crucial. It matters to anything that is grounded to the body, but it doesn't mean a hill of beans to the alternator, because the alternator isn't grounding through that strap. You can theoretically disconnect all the body grounds (strap to the motor, wire to the battery from the fender, etc. etc. etc.), and everything connected to the body (headlights, interior lights, radio, voltmeter/tachometer/fuel level gauges, and cigarette lighter come to mind), but the engine will still run the same, and the alternator will actually be under less of a load because it's not running all that stuff inside the interior 😛 Thing is electricity goes anywhere it has a path, and you may have stuff acting very weird interior-wise if you tried this.

Yes, to get a good voltage supply in the interior of the car (with all the things I listed in parentheses) you will need a good body ground, but it won't matter where the charging system related to the battery is concerned. If you checked voltage at the battery and it was initially low, there was a poor connection either between the alternator and the positive post of the battery, or between the engine block and the negative post of the battery. Or the regulator in the alternator wasn't energized.