Solenoid differences?

Over the years, I've learned to assume less, and ask more. Went to NAPA to pick up a new solenoid, counterguy asked if I wanted the Chinese one or the American one (more expensive). I went for the American one, but after I got home and checked the jeep, I noticed one difference between the two of them. The old one has three terminals, 2 big ones, and 1 little one. The new solenoid has 2 little terminals instead of one.

My plan is to use just the smaller terminal on the right and ignore/cap the one to the left of it, as the old solenoid has a flat spot to the left of the small terminal which is left blank. There is a terminal there instead of a blank spot on the new one. Will this work out, or should I take it back? In all other respects, they are identical.

I just want to make sure I don't fry the new solenoid, or the new starter, or the new yellow top, or the DUI, or the whole jeep. I once watched a friend of mine turn his brand new 1971 Triumph Spitfire into a flaming hulk, because he didn't notice the thing had a positive ground when installing a stereo. Took about 30 seconds from smoking harness to completely engulfed in flames. Witnessing something like that tends to stay in the old memory bank, even 35 years later.

 

Go ahead and use it. The extra terminal ("I" terminal?) provides +12V to the ignition at starting in some applications. The factory solenoid on my pickup had 3 terminals, and I asked the same question at the parts store. All the replacements have 4 terminals, and the 4th terminal won't matter if the app doesn't use it.

Note the ground through the base makes the field circuit ("S" terminal), and your fender needs to have a good ground too.

 

it will be fine, don't use the I terminal, originally it would connect to the coil to provide full voltage to the coil when cranking (bypassing the resistor). You wont need that with your dui.

edit: timgr just beat me to it!

 

Thanks guys! I'm gonna add a dedicated ground to the base mounting bolt. I've become a big fan of dedicated grounds, and redundancy. I am convinced individual components (starter, alt, dist, etc) last longer with healthy, happy grounds.