Not charging

[shatar4]

Just put the 505 in and the battery will not charge! When the 340 was in it I had no problems. So far I had the alternator checked and its fine, replaced the voltage regulator and the starter relay. Had the red top checked and it fine. Checked all the ground (battery to motor and motor to frame) and all checked out. When running the battery reads around 11.80. When revved up it only goes to about 12.10. I give!!

[shatar4]

Checked it and all clean. Did a voltage drop test from the alt. to the battery and it came up 1.47 drop. How do you find whats dropping it?

[brads70]

I'm guessing it's the bulkhead connector? 99% of the time it usually is?  Try Running a heavy wire from the alternator lug right to the battery.

[shatar4]

What gauge, about a 10g? Is it ok to leave it on there?

[shatar4]

I found the problem. I have two electric fans that turn on about 15 seconds after the car starts and it was drawing all the volts. I unplugged them and the volts shot up to 13.5 at idle. Now that I fixed that problem, no to fix the fan problem!

[brads70]

What gauge, about a 10g? Is it ok to leave it on there?

Yes I left mine on there,it takes load off the bulk head connector. its Moroso battery cable though. I previously has cable that was about 1/4" thick with no issues. If you still have a stock alternator it won't be enough to keep up and will slowly drain the battery. If your driving is just around town you can top it up with a battery charger but on a long trip it will draw down the battery...
I also have 2 electric fans to control them I used the Dakota Digital fan controller and a 250 amp alternator to power them. Your fan shouldn't come on till it gets hot enough.

[dodj]

I found the problem. I have two electric fans that turn on about 15 seconds after the car starts and it was drawing all the volts. I unplugged them and the volts shot up to 13.5 at idle. Now that I fixed that problem, no to fix the fan problem!

If your electrical system is stock, you really need to do the bypass Brad suggested. Those electric fans will likely melt your bulkhead connector.
You can leave it on indefinitely, but your ammeter will not really be giving you an accurate representation of current flow (not really a concern).

Any voltage drop is an indication of a less than perfect electrical connection. The high draw of your fans will make it worse and worse over time due to heating/cooling of those connections. IMO, take your bulkhead connectors apart and make sure they are clean and tight, same for the connector on the passenger side valve cover and the connections on your ammeter (if you still have). Disconnect the battery b4 checking the ammeter nuts - tooo easy to short out in the tight confines under the dash.

[shatar4]

I've already done the bypass. As far as the less then perfect electrical connection, the Contour fans draw as much as 50+ amps at start up. They can suck a bird threw the radiator. Awesome fans! I don't think my alternator can keep up with it, I think that's why I was getting the voltage drop. I had them on all the time because the probe they gave me didn't work and I wanted to be safe then sorry tuning up the new motor.

[dodj]

Ah. Well if that is the case, better buy the super power output generating station that Brad has. LOL.

[shatar4]

I'm not going that big! Mancini has a 140 amp that will be just fine. Thanks for all the help.

[shatar4]

Bought the alt. now whats the best routing for the wire to the battery?

[Chryco Psycho]

I usually go the long way back to the firewall & around the engine bay but you can go forward across the rad support with the headlight wiring

[dodj]

My preference is the shorter route across the rad support with the headlight wiring. It's easier.

[1970 RT Challenger 1970]

I'm guessing it's the bulkhead connector? 99% of the time it usually is?  Try Running a heavy wire from the alternator lug right to the battery.

If you run with the a Battery in the trunk with welding cable, where do you connect the 10 Gauge wire to? To the trunk or the other end of the cable under the hood? Thanks.

[brads70]

If you run with the a Battery in the trunk with welding cable, where do you connect the 10 Gauge wire to? To the trunk or the other end of the cable under the hood? Thanks.

I have the battery in the trunk. I used heavy welding cable from the battery to one of these mounted near the original battery location.   http://www.ebay.com/itm/Large-Black-Junction-Power-Post-Insulated-Terminal-Block-Stud-3-8-Stainless-/151981963191

I then run a heavy cable from the alternator to this "power post"  I also use it for power for other accessories.