12V solenoid relay question -

[mike_van]

I need a little help here - I bought two of these http://www.surpluscenter.com/item.asp?UID=2008011915125405&item=11-1108&catname=  hoping to use them in a winch control box I made up. I had two [not like these], you put 12 volts across the small terminals, bang, they close. Take the 12 V away, they open - Simple.  These 2 new ones however, don't work that way, in fact I can't make them work at all. 12 volts on the small terminals does nothing.  I took one apart, here's what it looks like    One terminal goes to the small copper wire, it's wound around the spool & comes out the bottom where it sits on the steel case. OK, that terminal & the case are grounded. The other terminal goes to the flat copper strip which goes to the make/break round copper disk. Theres no electromagnet thing I can see, no matter where you put 12 volts, this thing won't close.  Any ideas how it's supposed to work are welcome.  Two of these are soon to become .223 targets.

[ronwood]

mike_van

Did you attach the case of the solenoid back to the ground on the battery?

Ron

[Ironwood]

Mike,

I have a number of winches and cranes that use selenoids, they are not "momentary" types used on starters. They are much more expensive and can be used in the continously energized mode. I am no electrical engineer, but I am not sure you really got what you needed there. I believe the ones I get retail for $30-35.

                    I hope that helps, Ironwood

[mike_van]

Tried it all Ron,   nada, zippo -  The one I took apart, I put back together, with the top off, if I put 12 volts on the small terminals, then push the plunger down by hand, it will hold there until you break the connection - but there's no way to make it snap in like I believe a solenoid should.  Also, with it put back together, there's no way to manually push it down - I'm about out of ideas.

[mike_van]

Missed your post Reid - I know they make continous duty ones, these are for my truck crane, it's pretty intermittent,  for what it has to do & as small as the winch is, I thought I could get by with the cheaper ones. If I can find two like the other two I have,  I'll be ready to go - I had a Dayton drum switch on it for years, out in the weather, used it & used it - It finally gave out - The plastic/bakelite broke out of it - The copper contacts were still fine after all those years.  This box, I have hooked up with a 6' cable with the  2 way switch in it, so you have a little "range" away from the truck. 

[Furby]

I bought not one but two new ones a year and a half ago for my truck starter.
Both did that same thing and both were faulty.
Think they were around $35 at the store.
Bought a used one for $2.65 from the junkyard and it worked fine.
My guess is you bought junk ones, but that's just a guess.

[easymoney]

the relay you have is made for positive12v to be applied to one of the small terminals. the frame where you mount it acts the ground return to pull it in. the other small terminal is to furnish 12 volts to the coil to make a hotter spark while starting an engine.

[DanG]

I had to replace the one in my Ford truck recently.(Some of you may remember the snake story. :D )  They had 2 kinds, one for $10+ and one for $26+.  Guess which one I chose. : :D  Anyway, it lasted a couple of months and started doing the same thing, sticking in the on position.  I replaced it with another of the $10 variety a couple of weeks ago.  I cut the bad one open and found the contacts to be some sort of iron alloy rather than copper, and the spring was really wimpy, because the coil was really wimpy.  If(when) it fails again, I'll buy the $26 one.

[Slabs]

Is that coil wire in the photo going to one of the heavy terminals on the solenoid?  If so, which terminal  does the other coil wire go to?  Regardless, the energizing power has to go across the two wires going to the coil.  If that terminal in the picture is one of the big ones then that's probably where the battery wire should go and the other terminal going to the coil would have to be grounded to actuate the starter.  That would indeed be a rare configuration but if you have an ohmmeter determine which two terminals have continuity and if one of them is the large terminal then that's probably the configuation I suggested.  The small terminal that that "whisker" on the contactor goes to will definately be a spark booster for the old "Kettering" (Point-condenser) ignitions.

[mike_van]

There's joy in Mudville - The Giants won, and I finally got these solenoids to work. The one combination I didn't try [I thought it was a dead short] worked.  With the case grounded, 12V on the terminal you can see with the fine wire closes the solenoid. The other small terminal with the copper strip must be as Slabs & easymoney said, to sent 12 V somewhere else. Here I thought the Chinese sold me two dead ducks  :D          The picture shows all four in a box, I made up a 6' cable with a trailer plug, you can just see the jack on the right side of the box. There's a momentary switch on the end of the cable, up/down.   Up closes 2 solenoids, down closes the other 2 reversing polarity so the winch motor runs the other way. Thanks for all the help!