QuestionI read your response to 6.5 diesel stalling, and was very
impressed. I like the idea of wiring around the OPS in my 1999
Suburban with a 6.5 Is there a simple way to do this, a clip and
splice, or do I need to find a switchable power source and route
it to the transfer pump? There are also apparently 2 choices of
OPS replacement parts: 1 termina, and 3 terminal. What's the
difference, and which do I need? Thanks so much for your help
so far...I have learned a lot from your responses to other
questions.
AnswerMr. Brown,
Thank you for the compliment!
Please be advised that wiring around the OPS is something you must assume the respnsibility for. In this litigous society, you perform the modification at your own risk.
I am told that a gray wire leads from the OPS to the lift pump. Pull the connector at the OPS and I believe that you will find it to be a three wire connection (which answers your other question). Disconnect the power supply wire at the lift pump and then use a test light or ohmmeter, and a sufficient length of wire, to find out which of the wires at the OPS sends power to the lift pump (it may or may not be gray, as I described above).
Cut the wire leading to the lift pump at the OPS. Find the pink wire that supplies power to the injection pump. Splice the lift pump wire to the pink wire to complete the bypass. The lift pump will operate when the ignition key is in the "Run" position and turn off when you turn the ignition key "Off."
If you are handy with electronics and would prefer to retain the OPS, but use a relay to handle the current required by the lift pump, resubmit your question and I will describe a relay-based conversion.
