electric help needed

[john sutton]

I have a1970 911T, that I wanted to change out the batteries. I thought the old ones were weak and old, but with only the left battery connected I checked the amp draw and found it to be 5.5 amps!
I later tracked the draw down to the single red wire that goes to the back of the car and runs just about everything; alternator, ignition ecu, alternator ect.
Other than disconnecting every item that is powered by a red wire one at a time, are there any short cuts that might help zero in on the culprit with less skinned knuckles and improvised curses.
thanks
john

[Bob Kontak]

If you pull one fuse at a time you could possibly isolate the circuit.

[john sutton]

did that. The large single red wire form the left battery runs to the hot side of the upper fuse block to 1 and 2. However 1 and 2 are ganged together prior to the fuse and run as constant hot to the stuff I mentioned. Pulling fuses won't help, I thought that someone might be able to figure which component might be the weak spot in a '70.
thanks tho
sutton

[HawgRyder]

Sounds like you have a bad diode in the alternator.
Or possibly a bad regulator.
Any draw over a few milliamps when sitting key off and no lights on is bad.
You must track down the culprit.
Bob

[Neel]

Originally Posted by HawgRyder

Sounds like you have a bad diode in the alternator.
Or possibly a bad regulator.
Any draw over a few milliamps when sitting key off and no lights on is bad.
You must track down the culprit.
Bob

Bob's right on track!! Unplug your VR and see if the drain goes away.. I don't remember if your car had a contact point VR.. It was very common in the 'day' for the contact points to stick together and cause a drain..

[schumicat]

Bob is right, that is a large draw so you can probably rule out something like a dome light. If not the alt. diode maybe the rear defroster; those use lots of juice.

[john sutton]

Ok, guys, I'm officially stumped. Here is what I've disconnected both individually and altogether. the regulator, the alternator ( directly from the back of the alt.), both the cannon plugs that go into the console that holds the rear fuses ect; the and the rear heater element, cigar lighter and horn relay. I gotta hook them back up.
On top of that, the schematic that I have for a 1970 911 colored wires are different than the colors of the wires in my car. ( why would I be surprised)
what would you check next because I still get a 6.65 amp draw when I hook up the ground wire from the battery in series to the chassis ground.
thanks

[DRACO A5OG]

Trunk and door switches are jimmied closed and clock fuse pulled, right? This what I would do on my 3.2

[john sutton]

yep, clock disconnected and no lights on..........???

[DRACO A5OG]

If I may suggest, start pulling one fuse at a time to zero in on the offensive current draw. Slow but effective

I don't think you have constant fuel pressue from your fuel pump like the 3.2. Try the fuse trick.

[john sutton]

the draw of amps is from the hot side of the fuse number 1 and 2 which is ganged together. The draw is from the single red wire that comes off of the positive battery cable.
hope that helps.

[HawgRyder]

At one time from previous owner...alarm system installed?
If so...he may have "tapped" into the hot wire and bypassed the fuses...not correct...but some installers were lazy.
You really need to pull the fuses to find out if the draw is going through one of them.
Bob