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Discussion Starter · #1 ·
I am wondering if anyone else has had this problem. I never noticed it until I moved the battery to the trunk. Now after I drive around a while you can hear a noise coming from the battery. I already had a optima spray crap all over the battery box. The battery shop said that battery was dead. I assumed that the gel discharge was becasue the alt was charging a dead battery.

I already replaced the powermaster alt with a new one and its a new Optima redtop. Volts at idle and after reving up a little are within Powermasters range. I do have a cut off switch. The alt power goes to the ford solinoid which I think will have to be changed to meet NHRA rules. I think i have to run the power cable all the way back to make the shut off switch work.

Do you think that the cable going to the trunk could be too small? Or maybe I need to add a new ground from the block to firewall?

Any ideas?

Thanks everybody!
 

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You need to add a ground from the block to the fire wall. Not grounding the block to the chassis can cause all sorts of nasty issues.
 

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Discussion Starter · #3 ·
Thanks mugen, I just put back the factory ground cable, I had a new one that I forgot to put on. It goes from the intake bolt to a screw on the blower motor cover into the fire wall.

If the output is correct at the alt post and its almost the same at the battery, could it be that this noise always comes from optimas??? Like its just venting? I guess the next step it to set up a temporary volt meter gauge so I can see whats happening when I am driving.
 

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Sounds like the battery is being overcharged. The regulator is leaving the alternator on too much. Poor ground or too much voltage drop from the battery cable could be the cause.
 

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Discussion Starter · #5 ·
upsizing the battery cable is next then. Thanks
 

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I would up size the cable. Also it's not a bad idea to ground the battery to a good location on the body in the rear then run another cable from that ground point to the engine. This will help in charging and help with starting. A poor ground can also cause premature bearing wear in the engine and tranny.
 

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Discussion Starter · #7 ·
Thanks Mugen.
I also forgot to mention that there is a 2 gauge ground strap from the trans to the frame. As mentioned above the factory ground strap from the intake to firewall and the neg on the battery goes to the frame. All the aftermarket cable is 2 gauge welding cable.

I already have the 1/0 welding cable to run from the battery to the front just need to put it in, maybe this week.

Should I run some temporary wire from the trunk to front seat and set up my amp/volt meter to see whats happenening when I drive around? Would that help figure out the culprit? Am I right in that the amps are the thing to watch for or would it be the volts?
 

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Start the car. Turn on some accessories and lights. Using a volt meter, measure the voltage at the battery and the voltage at the other end of the battery cable at the front of the car. Let us know what the difference is.

Also measure the voltage at the engine. Pick a spot on the block and put the other voltmeter lead on a chassis ground. If you see any voltage, you probably have a bad ground.
 

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Discussion Starter · #9 ·
thanks for breaking it down for me. I'm on it and will report asap!!
 

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There should be less than 0.5 volt drop between the two ends of the battery wire (or any other wire in the system) I run 00 welding cable from the trunck of my 66 mustang to the solenoid. I don't get any drop.
Paul
 

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Discussion Starter · #11 ·
When checking the front i was checking at the side of the solenoid where the alt is wired to.

When checking in the rear I was checking the 2 batt posts, the trunk latch to the pos post and the post off the disconnect switch. All these numbers seemed to be the same.

The elec fan ran the whole time while the engne was running.

not running there is little differance (.01) between the solenoid volts and the battery volts. 12.66 before I started the car in front and 12.67 in rear.

not running there is no voltage present from the engine bay ground to any parts.

running showed a differance of no more than .02 (would be 13.72 in front and 13.70 to .71 at the rear.

interesting notes: while running with one probe on the shock tower bolt and one on the block it showed a negative amount of voltage in the 13. range. Also I didnt run the engine more than 5 or so minutes and it seemed like the voltage kept growing. 12.8 at start up 14.01 by the time I shut it off. I could not run it more right now but i will try and drive it around and check the volts tomarrow.

Thanks... more later

____posted pics yesterday, let me know what you think!!

<font size=-1>[ This Message was edited by: karguy1 on 10/24/06 11:44am ]</font>

<font size=-1>[ This Message was edited by: karguy1 on 10/24/06 11:46am ]</font>
 

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Discussion Starter · #12 ·
did another test run tonite.

lights on, fan on and drove around for about 20 minutes at the end it was 13.66 in the front and about the same in back.

The alt did seeem a little hotter to the touch than i think it should be. Installinng the new cables later this week and a dashmounted volt meter. Getting worried that i am headed down path.
 
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