Ford starter solenoid as an auxiliary battery relay

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Sluggo
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Ford starter solenoid as an auxiliary battery relay

Post by Sluggo » Fri Mar 22, 2013 11:19 am

A long while ago Colin suggested using a ford starter solenoid as my auxiliary battery relay. I've tried two different ones with the same results. When I hook it up it actually drains both batteries. My battery light comes on and you can watch both of my volt meters rapidly drop. If I disconnect the blue voltage reg wire I use as a switch it works fine but there is no charge to the auxiliary battery. Same thing if I move the blue wire from the "S" terminal to the "I" terminal. If I hook up a standard Bosch relay all is good. I just want something beefier in there because I don't trust a standard relay with all that juice.
:vwgauge420:

1977 Bus with Sunroof - "Lucky '77"
2000cc Type IV w/Dual Weber 36s,
Aircooled.net SVDA w/Compufire,
Redline Weber Fuel Pump,
Holley Regulator,
Half Ass Brush & Roller Rustoleum Paint Job,
Incomplete Custom Interior,
Dual Batteries,
Crunched Slider Door.
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Re: Ford starter solenoid as an auxiliary battery relay

Post by airkooledchris » Fri Mar 22, 2013 1:43 pm

you want beefier - THIS is it

Image
1979 California Transporter

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Sluggo
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Re: Ford starter solenoid as an auxiliary battery relay

Post by Sluggo » Fri Mar 22, 2013 3:16 pm

Actually, I just bought an 85amp marine battery isolator about 20 minutes after making this post. Still curious why the ford starter solenoid had that reaction. :scratch:
:vwgauge420:

1977 Bus with Sunroof - "Lucky '77"
2000cc Type IV w/Dual Weber 36s,
Aircooled.net SVDA w/Compufire,
Redline Weber Fuel Pump,
Holley Regulator,
Half Ass Brush & Roller Rustoleum Paint Job,
Incomplete Custom Interior,
Dual Batteries,
Crunched Slider Door.
------------------------------------------------------

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Re: Ford starter solenoid as an auxiliary battery relay

Post by airkooledchris » Fri Mar 22, 2013 3:26 pm

was it cheaper than this one from Blue Sea? specs man specs!
1979 California Transporter

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Re: Ford starter solenoid as an auxiliary battery relay

Post by Sluggo » Fri Mar 22, 2013 3:35 pm

$16. 80amp (not 85). eBay. Made by Scorpion.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 1009318549
:vwgauge420:

1977 Bus with Sunroof - "Lucky '77"
2000cc Type IV w/Dual Weber 36s,
Aircooled.net SVDA w/Compufire,
Redline Weber Fuel Pump,
Holley Regulator,
Half Ass Brush & Roller Rustoleum Paint Job,
Incomplete Custom Interior,
Dual Batteries,
Crunched Slider Door.
------------------------------------------------------

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Re: Ford starter solenoid as an auxiliary battery relay

Post by hambone » Fri Mar 22, 2013 6:43 pm

Oh yeah Scorpion, I'd trust that name ANYWHERE and ANY TIME.
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Re: Ford starter solenoid as an auxiliary battery relay

Post by drober23 » Wed Mar 27, 2013 10:50 am

I'm not sure you want beefier. The original Westfalia setup had a lower voltage relay, and a smallish wire (10 ga?). The limit of what the wire would carry would keep the strain on the generator in a decent range.

I bet a search on that setup would reveal some good answers.
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(plus more busses than sense)

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Re: Ford starter solenoid as an auxiliary battery relay

Post by Sluggo » Fri Apr 05, 2013 4:58 pm

The one I got seems to be working well. It has a very loud click when it cuts on & off though. I am using 10g wire with 30amp fuses to cut down on current draw.
:vwgauge420:

1977 Bus with Sunroof - "Lucky '77"
2000cc Type IV w/Dual Weber 36s,
Aircooled.net SVDA w/Compufire,
Redline Weber Fuel Pump,
Holley Regulator,
Half Ass Brush & Roller Rustoleum Paint Job,
Incomplete Custom Interior,
Dual Batteries,
Crunched Slider Door.
------------------------------------------------------

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Re: Ford starter solenoid as an auxiliary battery relay

Post by Amskeptic » Fri Apr 05, 2013 10:47 pm

Sluggo wrote:The one I got seems to be working well. It has a very loud click when it cuts on & off though. I am using 10g wire with 30amp fuses to cut down on current draw.
I don't see why it is that people are attempting to reduce current draw through the size of the wires. That is a recipe for hot wires.

The wire *could* be asked to pass full alternator output if the secondary were dead out dead at start-up. That would be a nice 55 or 70 amp load, would it not?
Colin
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Chloe - 70 bus . . . 217,593 miles
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Pluck - 1973 Squareback . . . . . . 55,600 miles
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Re: Ford starter solenoid as an auxiliary battery relay

Post by Sluggo » Sat Apr 06, 2013 10:45 am

I've been running it with 10 gauge wire for a few years now with no issues. I've drained the battery at our campouts on several occasions without incident. Next time I'll go out and feel the wires after a full discharge and and charge.
:vwgauge420:

1977 Bus with Sunroof - "Lucky '77"
2000cc Type IV w/Dual Weber 36s,
Aircooled.net SVDA w/Compufire,
Redline Weber Fuel Pump,
Holley Regulator,
Half Ass Brush & Roller Rustoleum Paint Job,
Incomplete Custom Interior,
Dual Batteries,
Crunched Slider Door.
------------------------------------------------------

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Re: Ford starter solenoid as an auxiliary battery relay

Post by drober23 » Mon Apr 08, 2013 6:44 am

Colin,

I am not sure of the merits of running a smaller wire. I am just observing that the OG version was set up this way.

I am going to do this before my vacation this summer, and am also in the process of deciding how to do it. Keeping my eyes on this thread for ideas. I have seen discussions of this on the Samba, and folks seemed to make decent arguments for both ways.
DJ

'75 Westfalia, '79 Deluxe
(plus more busses than sense)

In a time of chimpanzees I was a monkey

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Re: Ford starter solenoid as an auxiliary battery relay

Post by Amskeptic » Mon Apr 08, 2013 8:30 pm

drober23 wrote:Colin,

I am not sure of the merits of running a smaller wire. I am just observing that the OG version was set up this way.

I am going to do this before my vacation this summer, and am also in the process of deciding how to do it. Keeping my eyes on this thread for ideas. I have seen discussions of this on the Samba, and folks seemed to make decent arguments for both ways.
I am not recommending a smaller wire . . . I was answering any notion that limiting current draw *by virtue of a smaller wire* does not make intuitive sense to me.

Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: Ford starter solenoid as an auxiliary battery relay

Post by sped372 » Tue Apr 09, 2013 5:58 am

Amskeptic wrote:I was answering any notion that limiting current draw *by virtue of a smaller wire* does not make intuitive sense to me.
It doesn't make any kind of any sense. Wires aren't supposed to be used as resistors, they're conductors. Trying to limit current by downsizing wiring is exactly the wrong technique.
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Re: Ford starter solenoid as an auxiliary battery relay

Post by RSorak 71Westy » Tue Apr 09, 2013 5:18 pm

Trying to limit current by downsizing wiring is exactly the wrong technique.

This only results in an overheated wire, with the amount of the heating directly related to the amp draw thru said wire, never a good thing.
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Re: Ford starter solenoid as an auxiliary battery relay

Post by Amskeptic » Wed Apr 10, 2013 7:08 am

RSorak 71Westy wrote:Trying to limit current by downsizing wiring is exactly the wrong technique.

This only results in an overheated wire, with the amount of the heating directly related to the amp draw thru said wire, never a good thing.

You read it here ^
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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