Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: 62 CDV on May 10, 2019, 12:26:48 PM

Title: Parasitic draw of power in my '62...
Post by: 62 CDV on May 10, 2019, 12:26:48 PM
Today I located the source of a parasitic draw of electricity in my '62 by pulling fuses when the car was fully shut off. (This includes blocking the door lamp switch to the OFF position). While pulling fuses one by one and then returning them back to normal, I saw the power draw drop from 220 milliamps to almost zero when I pulled the BODY FWD fuse.

Which circuits are controlled by the BODY FWD fuse? I'm betting that it won't be easy to trace them, but I want to trace the correct circuits and not mess up anything else.

Thanks in advance for the due diligence.
Title: Re: Parasitic draw of power in my '62...
Post by: Dan LeBlanc on May 10, 2019, 12:33:16 PM
 Power windows and seats for sure.

Its actually BODY FD (short for feed) 
Title: Re: Parasitic draw of power in my '62...
Post by: Eric DeVirgilis CLC# 8621 on May 10, 2019, 12:34:53 PM
I don't know whether this helps...

http://forums.cadillaclasalleclub.org/index.php?topic=137579.0
Title: Re: Parasitic draw of power in my '62...
Post by: Dan LeBlanc on May 10, 2019, 12:37:57 PM
If you don't have anything hooked in the adjacent accessory terminal, you can move the connector and circuit breaker to that side and then when the key is off, that circuit will have no power until you isolate the problem.

It just means you can only use the windows and seats when the key is in the accessory or run position.
Title: Parasitic draw of power in my '62...
Post by: bcroe on May 10, 2019, 03:36:34 PM
Quote from: 62 CDV on May 10, 2019, 12:26:48 PM
Today I located the source of a parasitic draw of electricity in my '62 by pulling fuses when the car was fully shut off. (This includes blocking the door lamp switch to the OFF position). While pulling fuses one by one and then returning them back to normal, I saw the power draw drop from 220 milliamps to almost zero when I pulled the BODY FWD fuse.

Which circuits are controlled by the BODY FWD fuse? I'm betting that it won't be easy to trace them, but I want to trace the correct circuits and not mess up anything else.

You need to get a detailed drawing of the car wiring.  Then you can continue your
process of disconnecting wires.  I doubt it is windows or seat, has anything been
added to the car that might have a drain?  Bruce Roe
Title: Re: Parasitic draw of power in my '62...
Post by: Cadillac Fleetwood on May 10, 2019, 03:39:56 PM
Interior courtesy lights, glove box light, trunk light, and cigarette lighters are also on that circuit.

-Charles Fares
Title: Parasitic draw of power in my '62...
Post by: bcroe on May 10, 2019, 04:45:19 PM
My wild guess is the glove box light is stuck on.  Bruce Roe
Title: Re: Parasitic draw of power in my '62...
Post by: arch62 on May 10, 2019, 06:13:30 PM
Not a wild guess. It happened to me, so I now placed a 1"x1" balsa wood piece to keep the plunger back. It would push through the vinyl before.
Title: Re: Parasitic draw of power in my '62...
Post by: fishnjim on May 10, 2019, 09:21:34 PM
You would benefit from having a low range amp clamp ammeter and check all the wires in that circuit for the one(s) drawing amps.   
A glove box light is around 3W.(typical 1891)   In a 12 V circuit it will pull 0.25 A or 250 milliamps, so that's a valid lead(or other 3W users) to run down from your measurement .
The other thing is to check for hot spots.   V=IR , 12=.25R, R= 48 ohm of resistance, should heat up a tad, due to corrosion, etc if not a light but leakage.   IR non-contact thermometers are pretty cheap these days.   {I warn about this old wiring corrosion, as left alone, it can flame up.}
Title: Re: Parasitic draw of power in my '62...
Post by: TJ Hopland on May 11, 2019, 08:46:15 AM
Know of anything that isn't working?  Especially something run by a relay?   Run into it before where at some point in a cars life something went wrong causing a relay to always operate so the fix was disconnect what ever the relay was running instead of soling the actual issue.    This left the relay still always on and drawing power as well as something not working like say a direction of the seat?
Title: Re: Parasitic draw of power in my '62...
Post by: V63 on May 11, 2019, 07:22:20 PM
Check the recesses of the lighter sockets for foreign conductives? 
Title: Re: Parasitic draw of power in my '62...
Post by: 62 CDV on May 17, 2019, 08:10:45 PM
At long last, I found the source of the parasitic draw of power. It was located in the glove compartment light bulb. When I pulled the bulb, the power draw went from 220 milliamps to zero. (Maybe I should get a different bulb?).

I now can tell you that things like the power seats, power windows and clock are NOT part of the BODY FD circuit (at least they're not in my car). They all were operable after I pulled the fuse.  I'm guessing that it's just the interior lights and cigarette lighters that are fed from that fuse.

THANK YOU FOLKS FOR ALL YOUR HELP HERE. I do appreciate it.