View Single Post
makoco makoco is offline
Registered User
Join Date: Nov 2008
Posts: 2
Thanks for the information and the diagram, I will check the boost control relay, I did read through bosh bulletins that the pump relay is grounded through the control unit where in deed the boost pressure limited is wired to.

Also the engine has to spin at least 30 rpm in order to close the ground circuit through the control unit (in order to avoid having the pump running when the ignition is on a the engine not operating (like in case of an accident))

My concern is the fact that I did turn on the ignition switch and after noticing that the pump did not operate at once I proceed to jump the relay, primed the pump and w/the relay jumped proceed to start the engine and it did.

After that I check the relay and found out it was operating normally proceed to check the contacts on the relay circuit to found out that the ground loop out of the relay was not completed. Furthermore I did ground the relay and the circuit was complete closing as well the pump circuit and obviously operating.

When I grounded the relay it was also connected to the brown wire coming from the control unit. It is my concern that I have probably damaged the control unit.

Is it possible to damage the control unit when connecting the ground (the way I did)
Old 11-30-2008, 08:50 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)