buddy of mine has a 3.4 taco with a 5spd. it wont go into 4wheel drive. started checking things and have a question about the t-case switch. two leads going into the switch on the t-case, one shows ground, the other shows 12+ volts. if i test the lead that reads 12+ volts with a cheapy test light it will trips the vacum switch and lock the hub, however if i test it with a test light that is circuit protected that lead reads 12+ volts no matter what gear the t-case is in.
it seems to be that the switch should triggers ground for the hub to lock and that the switch is not working right.
any thoughts, advise?