I tried posting this question earlier and didn't know what I was doing so I'll try again. I have an older TB42 Snorkel lift and it won't switch to hi-idle unless I manually pull the solenoid back with the switch engaged. I've tested the relay out and it seems to be sending the signal. This also happens when I try to operate the choke. The throttle solenoid has 3 wires and the choke has 2. I did pick up an answer from some out there but lost the reply so I'm trying again. Thanks, Mayn4u
Cummins had a similar problem with the fuel shut-off solenoid on their inline pumps. The solenoid actually has two coils, one high current to pull the lever back and one low current to hold the lever. There are three wires - pull back positive, hold positive and common ground. Usually the pull coil burns out but the hold coil is still OK, so you can pull it back like you say and it will stay on. A border-line coil may only act up when hot. The 2 wire solenoid on the choke may be getting weak? Or maybe there isn't enough power? (bad ground, low voltage level/bad regulator, corroded connections, etc.) This would explain why both solenoids are giving you problems. Many machines use the chassis as the main ground, which can be trouble as the machine ages and joints corrode. ISZ
Thanks ISZ, I check the current and it was getting full voltage. removed the solenoid and bench tested it with same results. I was getting ready to order a new one and noticed the sol. also had an aux. terminal. So I hooked it back up to the battery using the aux as my + and "viola" it worked like a new one. Problem solved. I'll reinstall it later today. Thanks so much for your info. Mayn4u
Not so mayn4U, if that solenoid has three terminals and one is marked Aux, that aux terminal can not have constant power or it will burn it up. The aux terminal is the pull windings, has to be connected to a time delay relay or something similar, can't have power on that terminal more than 5 or 6 seconds or you'll toast it.
Gas or Diesel?