OK I need an electrical experts help so I can find the correct part. I installed a shift lever (auto truck) with the OD button in the end. I want to use this button to control TC lockup. Problem is I don't think its a two position switch just a momentary switch. So I'd like to get a relay that is controlled by a momentary switch, but what is a relay like that called? And do you know where to get one?

 

If I understand correctly, you have a momentary on switch, and you want to use that to control a relay that stays on. A latching relay would work, except you would have to have some external means to unlatch it. A two position stepping relay would work, though. Finding one will be difficult, unless you are familiar with electronics. I would try the surplus sites.

You could also use a simple logic circuit to control an ordinary relay. Here is one that uses the relay itself as the logic element. It should do the trick. Scroll down to the Pulse Relay circuit.

 

Thanks. So a stepping relay would require nothing else but the momentary switch as a control?

 

Yes, and two position stepping relays are also known as latching impulse relays, and sometime impulse latching relays, which should make your search easier. Be aware that most do not have 12 VDC coils, and that some require polarity reversal to switch. In short, make sure you know that what you are getting will do the job

I think this one will do the job. It appears to be nothing more than a push on/push off switch operated by a small solenoid. If you order one, please verify it will work for you first.