TCC solenoid blows fuses

['75]

I bought a new normally open pressure switch and put it in the trans during rebuild, but didn't replace the lock up solenoid. Well I should have known better, the solenoid was bad and had lock up constantly. I bought a new solenoid locally from Advance BWD brand S9811 and installed it, it popped the fuse initially that I had piggy backed into, so I replaced it and drove it again. Converter didn't lock up in 4th like planned. I found the pressure switch got smoked too. I tested the new solenoid and found it draws 17 amps, pretty sure that's way too much. I'm going to return it and get another one, but I cant find a n.o. pressure switch locally. Does anyone know which parts chain might have it and how it's listed?

 

[mikestertwo]

I bought a new normally open pressure switch and put it in the trans during rebuild, but didn't replace the lock up solenoid. Well I should have known better, the solenoid was bad and had lock up constantly. I bought a new solenoid locally from Advance BWD brand S9811 and installed it, it popped the fuse initially that I had piggy backed into, so I replaced it and drove it again. Converter didn't lock up in 4th like planned. I found the pressure switch got smoked too. I tested the new solenoid and found it draws 17 amps, pretty sure that's way too much. I'm going to return it and get another one, but I cant find a n.o. pressure switch locally. Does anyone know which parts chain might have it and how it's listed?

Are you sure you didn't wire the solenoid backwards? There is an internal diode in the solenoid to prevent back emf. If you wire the solenoid backwards you will forward bias the diode and create a short.