Bodywork, Paint, Interior, Trim, & Wiring

discussions about bodywork, paint, interiors, trim, audio, electrical components, wiring, etc.

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BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Wrong flasher can run battery down
Posted by: BlownMGB-V8
Date: March 04, 2018 07:25PM

My MGB with AA wiring uses a 3 post flasher unit for both the turn signals and the hazard. I had an issue with the battery draining over time and eventually tracked it down to the flasher unit. There are now a bunch of 3 post flashers available. I was using one that had "35" in the number and had a 36 in the turn signal circuit. The hazard circuit showed a 200 ohm resistance when switched off and with the fuse pulled. That's a continuous 65ma drain and will ded the battery over a week or so of unuse. Switching the flasher to the 36 fixed it.

I may have got the numbers backwards. If you have this problem just pull the fuse and check for voltage across it. If there is, you can check resistance on the load side to ground, it should be infinite.

Jim


rficalora
Rob Ficalora
Willis, TX
(2764 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

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Re: Wrong flasher can run battery down
Posted by: rficalora
Date: March 05, 2018 11:29PM

Interesting Jim. I'm going to check mine.


Rebrean
James Russell

(1 posts)

Registered:
05/30/2021 09:15AM

Main British Car:


Re: Wrong flasher can run battery down
Posted by: Rebrean
Date: May 30, 2021 09:18AM

Thanks for the advice! Batteries can fail for various reasons, such as inaccurate float charge voltage, loose inter-cell links or connections, loss of electrolyte and high and uneven temperatures, as well as aging and lack of maintenance. The cycle life of Li-ion batteries is affected significantly by the depth of discharge. The depth of discharge is the amount of a battery's storage capacity that is utilized. I found out about all these things while browsing https://batterytools.net/ where there are a lot of articles related to batteries.



Edited 1 time(s). Last edit at 05/31/2021 01:24AM by Rebrean.


Jim Stabe
Jim Stabe
San Diego, Ca
(829 posts)

Registered:
02/28/2009 10:01AM

Main British Car:
1966 MGB Roadster 350 LT1 Chevy

authors avatar
Re: Wrong flasher can run battery down
Posted by: Jim Stabe
Date: May 30, 2021 11:15AM

Maybe I'm just noticing but what's up with the new wheels in your avatar picture?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Wrong flasher can run battery down
Posted by: BlownMGB-V8
Date: May 31, 2021 08:54AM

I anodized them

Jim


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