There has been so much debate and experimenting with the PTO wire on the CTD that I thought it might be good to relate what the service manual actually says about it. This should clear up any misunderstanding of its use. This wire is about in the middle of the firewall harness and is labeled "PTO" It will not in any fashon provide a high idle for the CTD.

In the index of the 1999 service manual look up “PTO Switch Sense”

Section 14-39 reads:

PTO Switch Sense – PCM Input: This PCM input is used only on models equipped with aftermarket Power Take Off units. The input is used only to tell the PCM that the PTO has been engaged. The PCM will disable (temporarily shut down) certain OBD II fault codes when the PTO is engaged.

Operation: When the aftermarket PTO switch has been engaged, a 12V+ signal is sent through circuit G113 to PCM pin A13. The PCM will then sense and determine that the PTO has been activated.

Section 14-111 reads much the same only for ECM sense.

 

My 1996 4x4 360 has that wire hanging out and was wondering what it did. So much for that idea... The guys that installed the underhood compressor didn't hook to that wire, I wonder if they should have. ???

J-eh