The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 09-24-2017, 10:21 PM   #26
AussieinNC
Moderator
 
AussieinNC's Avatar
 
Join Date: Jun 2017
Location: Cherryville, NC
Posts: 2,204
Re: can parasitic draw be caused by wrong bulb size?

Unplug the regulator and let us know the draw ..ign off...

Thanks
AussieinNC is offline   Reply With Quote
Old 09-24-2017, 10:39 PM   #27
andrewpclayton
Registered User
 
andrewpclayton's Avatar
 
Join Date: Aug 2017
Location: Eugene Oregon
Posts: 128
Re: can parasitic draw be caused by wrong bulb size?

.95
__________________
1977 SWB (c20 conversion) SBC350
Springfield Oregon
Instagram: @nevernotchevy
andrewpclayton is offline   Reply With Quote
Old 09-25-2017, 07:31 AM   #28
drfloyd
Registered User
 
Join Date: Sep 2015
Location: Scranton, SC
Posts: 248
Re: can parasitic draw be caused by wrong bulb size?

Quote:
Originally Posted by franken View Post
The answer to the original question is no.
A - current flow means you have the meter leads connected backwards of what the meter thinks is right. Actual current flow direction theory is up for debate, but makes no difference.
Swapping parts for no real reason wastes money. That's called shotgunning. Troubleshoot.

Electric systems are simple, but hard to figure out. A circuit is a circle from the source and back through a load. A load is something like a group of lights such as park lights or whatever. From the battery/alt the exact same current flows to and from said circuit. Its a circle. Nothing is lost or gained in the circle.
E=IR
or elecromotive force, (Volts) is equal to current times resistance. You can transform that w/ simple algebra.
Thanks Captain Obvious. Nice Google search.
drfloyd is offline   Reply With Quote
Old 09-25-2017, 08:08 AM   #29
mjshealy
Registered User
 
Join Date: Sep 2017
Location: Shacklefords, VA
Posts: 21
Re: can parasitic draw be caused by wrong bulb size?

Different reading with the alternator can be misleading. This is because on a lot of older cars/trucks, the alternator wire runs to the starter solenoid, and sometimes there are other factory/accessoriesattached there or at the alternator stud itself. The OP needs to be familiar with meters and settings. When you originally said .75 amp draw, I am unsure of if you know what the actual reading is.... .75 amps, 750 milliamps, .750 milliamps? the first thing I would do is buy a small cheap battery load tester and test the battery. You can also start the vehicle, let it run for at least 10 minutes, write down the battery voltage running, then take off the battery terminals as quickly as possible and hook your meter leads to the battery. Write down what you first see when you hook up the leads, then what it finally settled at.
mjshealy is offline   Reply With Quote
Old 09-25-2017, 08:36 AM   #30
Bigdav160
Registered User
 
Bigdav160's Avatar
 
Join Date: Apr 2011
Location: Klein Texas
Posts: 3,852
Re: can parasitic draw be caused by wrong bulb size?

Another way to find a parasitic draw is to place your meter in milivolts range and place the meter leads across each fuse. A circuit carrying current will show a small amount of voltage drop across the fuse.
__________________
My Classics:
'72 K20 Suburban + '65 Dodge Town Wagon
'72 Corvette Roadster +'67 Corvette Roadster
'73 Z-28 Camaro
'63 Ford SWB Uni Pickup
'50 Ford Coupe
Bigdav160 is offline   Reply With Quote
Old 09-25-2017, 08:40 AM   #31
mjshealy
Registered User
 
Join Date: Sep 2017
Location: Shacklefords, VA
Posts: 21
Re: can parasitic draw be caused by wrong bulb size?

In my opinion, it won't be the bulb, if it's a regular bulb type. LED's can operate on minimal power, so the slightest residual power left through the switch could drain power, but if it was the middle of the night and dark outside, you would see the light on, dimly lit.if you want to "throw parts at it", replace the wrong bulbs with the correct ones. But as long as the power requirement on the incorrect bulbs you installed are at or above the correct bulb specs, it's not going to drain unless the actual light is left on. When the switch is off, there is no or very little residual power to the bulb.
mjshealy is offline   Reply With Quote
Old 09-26-2017, 12:04 AM   #32
andrewpclayton
Registered User
 
andrewpclayton's Avatar
 
Join Date: Aug 2017
Location: Eugene Oregon
Posts: 128
Re: can parasitic draw be caused by wrong bulb size?

Found it! The PO removed the horn for some reason but the horn relay switch was plugged in. The steering wheel is pretty hammered and there isn’t even a spring in it for a horn button.. I’m thinking they couldn’t get it to work with this “new” steering wheel.. I’ll find a new one soon enough but I think I’m good on the parasitic draw and I have a shiny new alternator lol
__________________
1977 SWB (c20 conversion) SBC350
Springfield Oregon
Instagram: @nevernotchevy
andrewpclayton is offline   Reply With Quote
Old 10-16-2017, 05:15 PM   #33
andrewpclayton
Registered User
 
andrewpclayton's Avatar
 
Join Date: Aug 2017
Location: Eugene Oregon
Posts: 128
Re: can parasitic draw be caused by wrong bulb size?

OK I didnt have it like I thought.

when I disconnected the horn relay, I also had the external regulator disconnected so the reading went to 0

if when I disconnect the external regulator the reading goes to 0, is that indicative of a faulty relay?

I purchased a replacement external regulator and connected it, the reading went up to 2.35, so I put the old one on and we are still at .80
I did not however turn the truck on so maybe it didnt get a chance to "activate"?
__________________
1977 SWB (c20 conversion) SBC350
Springfield Oregon
Instagram: @nevernotchevy
andrewpclayton is offline   Reply With Quote
Reply

Bookmarks

Tags
battery, lighting, parasitic draw


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:20 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com