Hello; After working on the truck the last few times I've disconnected the positive terminal from the battery and have left the negative terminal connected. After only 2 days the battery dropped below enough voltage to turn the starter motor. I have no idea where to start looking for issues. The quick specs are as follows:
1951 chevy 3600 converted to 12 volts including adding an alternator, switching headlights to relays. starter is original (6 volt) blower motor is new (12 volt) and in-line fused powered from ignition switch steering wheel horn button is currently disconnected added an accessory terminal block with 6 fused circuits (Hi beam, Lo beam, flasher, lighter, 2 unused (future))
Battery currently reads 10.5 volts without cables attached, but reads 6.5 volts with both positive and negative cable attached. So based on previous threads its possible there's a bad cell in this battery.
I have 2 questions; Can there be a drain on the battery even though the only cable connected was to the negative terminal? Is there any Tech page that would help me isolating the cause of my battery drain issue?
Your “drain issue” is caused by a bad battery. You can not have any parasitic drain on the battery if the positive cable is not on it. No way to complete the circuit.ðŸ›
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
There can be a very slow discharge without any cable, including just the positive in a normally functioning battery but nothing like you describe. There must be a problem with the battery or your cables and connections.
Is there a lot of crud on top of the battery between posts? If so, that could cause a faster than normal discharge. Even a good battery in storage will slowly discharge, but not in two days (maybe two months). I agree with the other guys - there's a problem with the battery.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Does the battery drain with the negative terminal disconnected. Have had a battery with 60 ma current flow with only negative terminal connected. I put piece of old belting under battery to isolate and had no further discharge problem while using that battery
Does the battery drain with the negative terminal disconnected. Have had a battery with 60 ma current flow with only negative terminal connected. I put piece of old belting under battery to isolate and had no further discharge problem while using that battery
If that was the case, then you definitely had a battery problem. Nice temporary fix, nonetheless.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
1. Yes the battery had a bad cell but also 2. there was a 2 amp drain was coming from the alternator.
When I switched from 6 to 12 volt I followed others' instructions to run the excite wire (alternator DA plug wire with diode) from the alternator to the middle post of the ignition switch so that the key will kill the power on shutdown. It worked (turning off the key turned off the vehicle) but I never tried it WITHOUT the excite wire connected. When I found the battery drain I disconnected the excite wire from the ignition switch and the key still shuts off the vehicle. I'm not very experienced in all this but capable of learning. I guess I never questioned the idea of connecting the excite wire from the new alternator so like a lemming I followed along. Glad I finally isolated the drain though.
I believe that the exciter wire is supposed to be wired to light bulb with the other bulb connection going to ground. It has a dual purpose of providing resistance though the exciter wire, thus "turning on" the alternator, and provide an idiot light to indicate when the charging system fails. Wired this way, when you turn on the ignition, the idiot light (wired to the exciter wire) comes on. Once the starter turns the engine over (as well as the alternator pulley) the light goes off. The light stays off until the engine stops running (with the ignition switch still on), or when something in the charging system goes bad. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
I burned up 3 alternators before I fully understood that I didn’t have an actual 1 wire alternator. I ended up attaching the executor wire directly to the other and it has been working great. I never did hook up the second blade.
