I've had a no start condition about 8 times in the last 3 weeks.

I changed the starter for the hell of it. (picked up a Denso for the Valiant anyway, so I swapped it into the van just to test it, and left it.)

tonight I charged the battery fully (charges fast. @ 12 amps it charged 100% in 20 min while I ate dinner).

I started van, shut it off, bridged analog meter across battery. it read just over 13v.

i started it again. dropped to 9v for a second, then jumped up to 14+v and held steady.

gunned the motor to see if regulator was working. needle jumped 0.2v or so max.

turned off motor, set key to 'off,' disconnected neg cable, connected meter between neg cable and neg post.

meter read 7v, steady.

only key-off voltage draw I know of is clock wire to radio.

that shouldn't be 7v, should it?

any suspects?

I'm going to leave the battery disconnected other than when I'm using the van until i figure it out.

Could it be an unswitched electric choke?

_________________
/6 '67 Barracuda convertible, electronic ignition, 4-OD, street cam, SBP KH discs, 3.55 SG 7.25" 1" t-bars. Bilstein.
340 '67 fastback, Doug Nash 5-speed.
1988 Toyota pickup work truck

One possible way is to remove the fuses one at the time, and see if the VM reading changes. Then at least you may be able to limit any further search to one part of the circuit.

Olaf.

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Aspenized

not likely. Choke is switched @ oil pressure switch. (Current to oil pressure switch is switched @ key, I think.)



I did this first thing this morning. Only one fuse has any impact, and only accounts for about 3v

It was the #6 fuse. I have no manual telling me which fuse does what, but without it, the horn and dash lights don't work.

Although it is only a small part of the "leak" it might be pointing to another problem: The dash light at the headlight switch doesn't work. I wonder if it can short out enough to fail to light, but not enough to blow a fuse.

My battery pos. cable terminal has 3 wires coming from it: a 14 ga wire that I don't know what it does. Disconnecting it has no affect on the leak voltage.

There is a #4 or so wire that seems to go to power everything but the starter and whatever the 14 ga wire powers.

Then there is the starter motor wire.
When isolated, it only accounts for <3v. (I did not disconnect the cable @ the starter to rule out it grounding internally since I purged the toolbox in the van of all metric tools, and could not remove the 13 or 14 mm nut on the denso starter.)

Thanks for the replies.

I would not be looking at voltage, but current. A common sensitive meter is 10,000 Ohms per volt. Meaning that 7V would represent 70,000 Ohms resistance or a trivial .18mA drain at 12.6V. The battery has more self-discharge than that. Measure the drain current (a 1 amp scale is probably alright, but starting at 10 would be better) and let us know what you find.

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Joshua

2.5 A with #4 wire attached.

.05 A w/it disconnected.

I forgot to check with the #6 fuse pulled.

Will do tonight.

Thanks.

(I'm starting to wonder if this has something to do with a badly cracked insulator on the alternator bat. wire. The van was off the road for a couple years. During that time it had a battery drain I couldn't find. I had cleaned up the motor, painted some tinware and cleaned up the wiring harnass. The drain mysteriously disappeared during this time. Maybe crap on the alt. bat. terminal is, and was, grounding it out. I'll disconnect tonight or this weekend and see what happens.)

I rebuilt my engine wiring harness a few years back as the same thing was happening as you described. Three wire had melted and were touching. The alternator charge wire was one of them, the oil light was another, etc......

Replacing the wires and ends in the connector did the trick!
No more strange shorts, odd ball dash readings and battery drain.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

2.5 amps is a hefty drain. I would pull fuses to see if you can isolate it to one circuit.

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Joshua

I did.

With an analog voltmeter (on my dwell/tach) I found one fuse that affected the volt reading by 3v. (as mentioned earlier)

The same fuse had zero affect on the amperage per my digital multimeter.

I think I just have to slice the harness open (I was hoping to not do that until after my HEI conversion, when I should be able to eliminate 1/4 mile of wire from the harness).

A battery charging fast is not a good sign. ( not much plate area left to charge)
Although if the battery was taking 12 amps(measured ) and 20 mins to charge it may still have some life left.
I would be taking the battery to get a load pull done at a battery supplier.
Just ask them to test your battery,usually free)
Do this before chasing current leaks.
The more times a lead acid battery is drained below 80% capacity the shorter its life span.

If you want to measure current drain ,do it with your meter set to 10A ,and put the meter wires in Series between your battery and the removed + terminal clamp. Any more than 50 or so milliamps (for radio memory, clock etc) is a problem.
Always ensure your battery is in top order before chasing electrical problems.especially if you have starting problems.
A battery needs to supply many Amps when trying to start a cold engine.(CCA) if it is not in top order it cannot supply the current needed, but will run all the other accessories ok ,as they dont take too much current generally.
Good luck and get that test done on the battery before chasing faults.
Brendan

PS also make sure all your negative straps have clean connection points.

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1963 AP5 Valiant 225 PB 904 Stock except extractors & 2 1/4 inch exhaust.


1962 S series valiant 225 PB auto. factory every thing. Full restoration job.
Currently on hold till AP5 is on the road.

I had a mysterious drain on another car,turned out to be a faulty diode in the alternator....the voltage reg was built into the alt and it was also swapped out during troubleshooting . Perhaps disconnect the alt cable to see if that helps before you go chasing wires in the harness.

I can't attribute a 2.5+ amp drain to a battery.

The only 'starting' problem I have is when the battery drains below 12.1v. I installed a cheap anti-theft battery switch and have no problems with the battery or starting. It's just inconvenient.

Unplugging one engine harness connector caused the amp drain (across the open battery switch on the neg terminal) to drop below .02 amps. (disconnecting all other connectors had no such effect.)

I checked resistance to ground of all the terminals on the engine side of that connector. Only one terminal had a reading that wasn't "0L."

I closed the battery switch and measured amps between that terminal and the corresponding terminal of the battery end of the unplugged connector.

It read >2.5 amps.

The wire was 14 ga (or so) and solid red.

A wire that looked identical was on a connector to the ESA.

I unplugged that and the amps dropped to 0.

I'm going to order the rest of my HEI stuff and finish rebuilding my EI distributor this week.

I think chasing this down will be much easier (or possibly irrelevant) with the ESA eliminated. (Lean burn distributor harness is all stiff and cooked, but disconnecting the engine harness it is connected to does not affect drain.)

Thanks for all the replies.

No ,I see you found it earlier, wire no #4.
I missed that sorry.
Yep that will do it.

I read the first line in your first post: Many a starter motor has been changed due to a dying battery.
good thing you had one spare and did not go and buy another.
I have changed a couple myself only to find out the battery was going bad.
Now the first suspect is always the battery.
Why is it flat ?
failing ,or current drain.
Imagine chasing a similar problem on a modern vehicle!!!!!!!

Well done on your repair
Brendan

PS Steve ,I must remember the leaking diode scenario if ever chasing a current drain.That could cause some head aches.

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1963 AP5 Valiant 225 PB 904 Stock except extractors & 2 1/4 inch exhaust.


1962 S series valiant 225 PB auto. factory every thing. Full restoration job.
Currently on hold till AP5 is on the road.

Still chasing short:

Turns out ground out @ ESA was just looped through bulkhead connector, or so it seems.

W/bulkhead disconnected, short @ ESA goes away.

I pulled the whole harness from the bulkhead conector to the engine harness(es).

I examined all wires for damage and pulled off some unused wires (A/C & cruise which were both eliminated).

Only damage was @ fusible link to alternator and connector to wiper motor.

I repaired the fusible link and made sure the wiper motor wires were fanned out and not toching anything until I can get a replacement connector (or mayby just install a series of female spade terminals).

None of this had any impact on the drain.

I rewrapped the harness. (I will tear apart again after eliminating lean burn and rewrap a little more 'professionally.')

No fuse had any affect when removed so I checked amperage @ fuses w/everything turned off and all fuses installed (if fuses not blowing, and fuse removal not breaking short circuit, affected fuses should read less amps to ground than other fuses).

I could not find a discernable difference.

I pulled all fuses and checked ohms to ground from fuse terminals.

It showed that 4 fuses were grounded out on the supply side.

(one of my checks last week showed continuity to ground on several terminals on the inside half of the bulhead connector, but I thought I was doing something wrong.)

I must have a monster short between the inside bulkhead connector and the fuseblock somewhere under the dash.

I will repeat the fuseblock test w/bulkhead connector disconnected to be absolutely certain the short isn't in the harness that I had gone through this weekend (I don't see how it could be. I examined every inch of every wire.)

I bought a battery and I disconnect it when the van is not running.

(each fuse has 14+v whole running).

Since all fuses present the same volts and amps, I'm guessing the short affects everything to the interior of the bulkhead connector, upstream of the fuse block.

I redid the harness on my 86 last spring. That 14ga wire is probably for the emergency flashers.

Dave

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86 Miser 170,000+
2 1/4" exhaust
Holley 1920 #55
HEI MSD BLaster 2
17.8 mpg