Ghost in the electrical system

[Chet Zerlin]

Been out of town for a while. Just visited my BN6, put the key in the ignition, turned it and.....nothing. I had the battery on a trickle charger while I was gone (which showed green indicating the battery was ok) but I figured it was not correct and I had a dead battery so I decided to hook up my battery charger.

The minute I connected the charger to the battery my fuel pump and my pusher fan came on even though the ignition switch was turned off (and the key out of the switch).

Thinking that perhaps something had happened to the ignition switch and it was making a connection even though it was "off", I disconnected the wires from the switch, plugged the battery charger in again and....the fuel pump and pusher fan came on...even though my ignition switch was completely disconnected and the wires separated.

It's as if something is bypassing my ignition switch...

Never had any problem like this before! Any suggestions on what to check (and what might be happening)?

Thanks!
Chet

 

[LarryK]

Re: Ghost in the electrical system????

Unhook and test battery. Check grounds.

 

[Keoke]

Re: Ghost in the electrical system????

Generally speaking trickle chargers may not maintain an older battery at charge over significnt periods of time, I suggest a Battery minder for this application.

 

[Chet Zerlin]

Re: Ghost in the electrical system????

Thanks everyone for your quick replies!
Keoke, I misspoke - it was a battery minder that was hooked up not a trickle charger.
All of the battery cables are new and clean and it is well and tightly grounded to the chassis...

The issue is that hooking up the battery charger to the battery (let's assume it's dead) turns on the fuel pump and pusher fan even though the ignition switch is not in the on position. That's never happened before without turning on the ignition switch....so I'm mystified what happened to make it do that? And how to check it. How would those items get electric directly from the battery and not through the ignition switch?

Suggestions are greatly appreciated!
Chet

 

[Healey Nut]

Does the car have a battery isolater switch ?

 

[Chet Zerlin]

It has the stock battery master switch in the boot - is that what you mean? When I turned it off the fuel pump turned off and so did the fan. Turned it back on and fuel pump and fan came back on.

Clearly something is making that circuit live without involving the ignition switch.....

 

[Healey Nut]

Yes the battery master in the boot , .
Is the car positive or negative ground ?

 

[Healey Nut]

Im thinking some rodent has chewed your wiring while the car is stored creating a short circuit .
Check your wiring harness for damage .

 

[steveg]

Im thinking some rodent has chewed your wiring while the car is stored creating a short circuit .
Check your wiring harness for damage .

Agree with Healey nut. Lighting and horn circuits hot all the time could be supplying juice through a short. Remove horn fuse to help narrow it down.

 

[vette]

Chet, again I have not checked a schematic but i believe the contacts in your voltage regulator may be stuck together. The reason your battery went dead is because the contacts stuck and this will drain the battery.

 

[Keoke]

Re: Ghost in the electrical system????

OK Chet:

Open the output wired side of the ignition switch with the charger connecte, if fuel pump ETC turn off switch may be deefective???

 

[vette]

thinking more about it, the fuel pump is feed off the same terminal of the top fuse that has the power coming to it from the ignition switch. The fuel pump is not fused in original configuration. When you pulled the wires off the ignition switch you probably did not separate them. The run terminal of the ignition switch had 3 wires on it. One of the wires is the one that goes to the top fuse which then supplies the fuel pump without going thru the fuse. Off the other side of the fuse is such things as the wipers, and turnsignal flasher. IF I am right they also will work at the same time as the fuel pump. the 3 wires that were all on the same terminal at the ignition switch , one of them goes to the charge indicator light. the other side of the indicator light goes to the voltage regulator and is directly tied to the generator. I believe because of the stuck contacts in the voltage regulator that the power is feeding thru the charge indicator light to the 3 wires that were all together at the ignition switch, then up to the fuse and then to the fuel pump.

 

[Chet Zerlin]

Thanks everyone for your replies.
"Healey Nut" my car is negative ground. The car has been in an air conditioned garage that was newly built a year ago so I doubt rodents are involved
"Vette" I will certainly take a look at my voltage regulator as you suggested. However, when I disconnected the wires from the ignition switch I did separate them as you suggested...with no change in the result. Considering that, would your theory about stuck contacts in the voltage regular still be a suspect?
Looking at the wiring diagram, the "Petrol Pump" has two wires: one is to ground and the other goes to the "35 Amp" fuse. One wire on that same side of the fuse goes to the ignition coil and then a wire goes from that coil to the ignition switch (one of the two wires you mentioned). The second of those two wires goes to the "starter switch". Looking at that diagram I don't see any wire going from that fuse to the Voltage Regulator.
So I'm still at a loss to see where something would provide voltage to the fuel pump when the three wires going to the ignition switch are disconnected and separated?
What am I missing?

Thanks everyone for your help! Continuing ideas and suggestions are VERY appreciated!

Chet

 

[steveg]

A wiring harness Short could be introducing electricity into the switched circuit. From horn or lights circuits downstream from ign switch. You've proved the switch not the problem.
Friend had short in green brake switch wire which fused to adjacent horn wire making all circuits downstream of ign switch hot. Had to disconnect battery to stop car running.

 

[steveg]

How new is the fan install and is it running off the brake switch green wire? If so that might have burned the wire if fan still running when you put car away.

 

[vette]

Chet, the fact that you have separated all the wires from the Ign Sw and also from themselves would negate my theory. But another possibility that i have seen before is that the wires from the same circuit and still electrically near each other are touching together. This happens when the circuit wires have gotten very hot in the past and started to melt into each other. When I restored my BJ7 the wires on the back of the Ign. Sw were melted together near the switch, when I took them off the switch they were still touching. Of coarse if your harness looks very good then this is not the case. By the way, since your car has a separate starter sw then I will look at the schematic for the earliest 6 cyl. cars. Pg, 298 in the Bentley manual. Just for the record, your Ign. Sw has just 2 terminals and on the schematic you will see that there is a white wire coming off the switch going in a down direction and it goes to the Ignition Charge Warning light #37. The other side of this light bulb is a yellow wire that goes to the "D" terminal of the voltage regulator. It is possible that with stuck contacts in the voltage regulator that the D terminal is getting voltage from the A terminal which is connected to the battery at the starter solenoid.
By the way, I was in Sarasota for a spell the last 3 winters and boy do I wish I was there now. So I assume you can work on your car immediately.
Ok, if all the wires are separated at the ignition sw, then lets look at how the fuel pump can be getting power. There is something that we need to investigate. You mentioned that the pusher fan also runs with the fuel pump. where is that fan connected and could it be giving power to the A3 terminal of the 35A fuse. I presume that the fan is on at least 1 relay because they usually pull alot of amps. Now to me the fan/relay circuit for the fan is suspect. A couple other things to check. With a voltage tester, check for voltage on both the white wires that you took off of the ignition sw. They should both be dead. The one white wire I said goes to the charge indicator light, the other one goes to the ignition coil but also goes on to the A3 terminal at the 35A fuse. If the fuel pump is hot this white wire at the ignition sw will be hot as well. Power is suppose to go from the ignition sw to the A3 not the other way around. If this white wire is hot at the Ign. Sw. then the circuit is back fed and I am now suspecting something with the pusher fan. Do some of these checks and get back to us.
Didn't mean at repeat some of what Steve said. I type too slow.

 

[steveg]

Also your ignition coil is likely toast and maybe your points.

 

[steveg]

OK, not typing on my phone anymore (was on a road trip back from Barrett Jackson)...the critical thing here is did you just install the electric fan? If that is true, your problem stems from that.

 

[Chet Zerlin]

Hello again all,
The electric fan was installed by the previous owner a lot of years ago - it was in it when I bought it in 2015. Everything was working fine until I left town for the holidays!
I'm not able to get to my shop for a few days but when I do I'll check out all of these excellent suggestions and report back.

Thanks!
Chet

 

[RAC68]

Hi Chet,

While you are looking to identify the location of the fault, I would suggest that you isolate and better protecting each circuit/component with a fuse installation, either in the form of an additional box (easy access) or In-Lind as I did (for more direct application and easily hidden installation - will require the creation of a directory of Fuse locations). Although added work, the incorporation of individual circuit/component fuses on everything from fuel pump to headlights will greatly aid in identifying the cause of the issue you are addressing and may have even eliminate it from happening.

Since you are still looking for the source of this issue, it may be a good time when checking each electrical path to start a progressive installation that can continue at your pace after your present issue is rectified.

Just a thought,
Ray(64BJ8P1)