Elect 101 for this dummy! :)

[vesparex]

Good afternoon guys! I have a question.

1968 Bronco. New Centech harness installed a little over a year ago. All stock except I installed a 3 gauge cluster for oil/temp/volts. The original gauges in the speedo are not used. Stock alt and points dizzy. New voltage reg. Now, a new battery. No radio. Elect wipers.

I have had a draw. 3 amps registering on my volt meter. Didn't realize it at first till I finally killed my battery. Appeared to be intermittent. It would kill my battery after sitting 3 days or be OK for a month. Finally after replacing the battery and finding the new one dead again I began looking for a draw.

Disconnected the negative batt cable. 3 amps between the neg and post. Began puling fuses, one at a time. Still a draw. Called Centech. Very nice peeps. They asked that I disconnect the alt, in case a diode or something was bad. Still had the draw. They mentioned that EVERYTHING is fused except the hot wire that loops through the original amp gauge and continues to the fuse box. I then found I had USED that wire to pick up power for my aftermarket tach. BINGO! I found the issue. Disconnected that wire and excitedly checked to make sure the draw went away. Well, here is where I need your opinions/guidance.

I still read a draw between the neg cable and post, only now, as the meter probes are on the cable and post the draw lowers to about .09. Lift the probes, wait maybe a minute and re-touch, there's the draw but again it begins to lower.

Is this normal? This is where I am stymied.

Duane

 

[kjmssd]

The usual reason for an inrush of current the way you describe is a capacitor somewhere in the vehicle. Whenever power is first applied, larger amounts of current flow until the capacitor is charged. Now, where exactly the capacitor is is another question - possible stereo?

 

[dave67fd]

Consider the meter as well. I have seen some cheaper meters or meters that have a delay for stabilizing the reading. Also make sure your reading the meter correctly and it's on the correct scale. Many mistake the ma (milliamp) scale for the A (amps) scale especially if auto ranging. Maybe unlikely but happens. Other than that try disconnecting the voltage reg. as well as your coil/distributor if you haven't all ready.

 

[vesparex]

Consider the meter as well. I have seen some cheaper meters or meters that have a delay for stabilizing the reading. Also make sure your reading the meter correctly and it's on the correct scale. Many mistake the ma (milliamp) scale for the A (amps) scale especially if auto ranging. Maybe unlikely but happens. Other than that try disconnecting the voltage reg. as well as your coil/distributor if you haven't all ready.

No radio. Def the amp scale. Meter is a Craftsman.

http://vid4.photobucket.com/albums/y123/vesparex/IMG_00659_zps97e98833.mp4

 

[Broncobowsher]

Unplug the voltage regulator and see what happens.

 

[vesparex]

Unplug the voltage regulator and see what happens.

Did that.

Duane

 

[NJBronco]

I'd check relays. If you have a relay backwards it can do tgat as well. Meaning tge relay is constantly engaged takes more current to click and less to hold it. Easy enough to listen for. Only other thing I could think of is check your battery it self for a draw. It could have a short internally Something is not fused if you pulled all fuses and show a draw. Hook your meter up and start unplugging and re plugging everything. My vote is bad relay or backwards. Next would be a bad battery

 

[vesparex]

I'd check relays. If you have a relay backwards it can do tgat as well. Meaning tge relay is constantly engaged takes more current to click and less to hold it. Easy enough to listen for. Only other thing I could think of is check your battery it self for a draw. It could have a short internally Something is not fused if you pulled all fuses and show a draw. Hook your meter up and start unplugging and re plugging everything. My vote is bad relay or backwards. Next would be a bad battery

Ahhh relays! I will be doing this at lunch. I think I have 3, horn, headlights and heater.

Duane

 

[Nellybell]

I think that you might be seeing a grounded wire or component that heats up as you complete the circuit with the meter. The heating causes the resistance of the circuit to increase and the current reduces until some sort of equilibrium is reached. Does your carb have a 12V dashpot or electric choke? Anything else that might get unfused power?

good luck,

Ted

 

[vesparex]

I think that you might be seeing a grounded wire or component that heats up as you complete the circuit with the meter. The heating causes the resistance of the circuit to increase and the current reduces until some sort of equilibrium is reached. Does your carb have a 12V dashpot or electric choke? Anything else that might get unfused power?

good luck,

Ted

No, no dashpot or elect choke.

Duane

 

[Nellybell]

Did you use the ignition switch kit? I took a look at Mollie in your online garage. Nice ride.

Ted

 

[vesparex]

Did you use the ignition switch kit? I took a look at Mollie in your online garage. Nice ride.

Ted

Thanks!!!!

Yes, I did use their ignition switch. But with the ignition fuse pulled there is still a draw.

So Fri nite I pulled all the relays and flashers, individually, still a draw. So I disconnected the rear harness, still a draw. Disconnected the front harness, still... Got to the starter solenoid, disco'd the starter, still a draw. Went to the battery side of the solenoid. On this Centech harness, there is a yellow (BT) wire and a gray wire which I think is a fusible link? Both attached on the pos batt cable side of the solenoid. Well, when I disconnected the grey wire the draw went away!

So now what???

Duane

 

[Broncobowsher]

Most of the aftermarket wiring kits print on the wire what functions they do. Does that wire have any indication of what it does?

 

[Nellybell]

Can you trace the gray wire if nothing is printed on it? The Centech manual mentions an OPT1 wire that goes towards the fuse box but they indicate it is pink. Maybe they changed colors.

Ted

Edit
http://www.broncofix.com/viewtopic.php?p=1098281 This link shows the gray as a fusible link but not sure where it goes. Looks like Donk knows.

Good luck,

Ted

 

[DirtDonk]

The gray wire is probably the fusible link that Centech provides, to be connected to the 10ga Red "BAT+" wire that connects to the starter relay.
If the Yellow wire is the large 10ga job, it should be marked either "ALT+" or "BAT+" (or ALT CHG maybe?) because that's what would be the alternator's output wire for a stock charging system.

What is connected to the back of the alternator as a charging wire? Normally it would be the Yellow wire. If not, then you might have to trace that other Yellow wire until you can read what it says it is. Pretty sure that there are (usually) no other Yellow wires in that vicinity from Centech.

Paul