3B tach sender in the FSM

[beanz2]

We're trying to diagnose a problem with a turbo 3B installed in an FJ60. The BJ60 tach installed doesn't seem to work. We suspect the sender is bad, the resistance across the sender terminals is 550 ohms. The trouble is, we can't find the appropriate section in the FSM to diagnose the tach sender. Can anyone tell me what page and section it is on and on which manual (Chassis vs. Engine manual).

All we have at his shop is an 84 non US FSM and the manuals at Birfield.com.

Thanks in advance,
Dave

 

[cruiser_guy]

If you've got 400 - 500 or so ohms across the sender then the sender is OK. I've had several senders go south on my BJ60 and they end up as an open circuit.

 

[beanz2]

Thanks, Charles. Is the resistance range what is specified in the FSM? What is the section in the FSM please?

How do we test the tach itself other than removing and replacing it?

Dave

 

[cruiser_guy]

There is nothing on testing the tach itself. The FSM says about 400 ohms. I've had 400 ohms and up to 500 or so. I think it's all detailed in the chassis manual not the 3B engine manual.