I bought a Radio Shack switch (p/n 275-0646) that is rated 3A at 125VAC and 1.5A at 250VAC. How much amperage can it handle in an automotive 12v system? I want to mount it in my shift knob and use it to switch my trans brake on and off for backing up. The trans brake solenoid draws 7 amps. If I have to, I will wire it up with a bosch relay so the switch doesnt have to carry much load, but I would prefer to use the switch alone to keep it simple.

Thanks in advance!

Dan

You'd definitely want to use a relay in your set-up with that switch.

Also, that switch appears to be a momentary (ie. you must hold/press it in to keep the circuit on), not sure if that's want you want or not.

Thats what I figured, thanks for the reply. Yes it is a momentary switch. The trans brake has to engage reverse to back up so I want the momentary switch on the shift knob to make things easier. Thanks again for the help.