Diodes D7 and D9
Posted: Tue Jul 07, 2015 2:27 pm
I had to remove diodes D7 and D9 shown on the output schematic as part of circuit to control fuel pump and Fast Idle. Under some conditions with MS board off, a small amount of voltage will pass through D7 and attempt to power the MS board with power from the pump relay coil. I am also using the Fast Idle circuit, that has been modified, to control a fan which is always powered and has the same problem.
Both relays have spike protection and only about 100 ma is switched by Q3 and Q5.
After a year or more, no problems, but if these diodes have an important purpose I should know about, I would appreciate any help.
Thanks
Chandler
83 XJS V12 MS V2.2
Both relays have spike protection and only about 100 ma is switched by Q3 and Q5.
After a year or more, no problems, but if these diodes have an important purpose I should know about, I would appreciate any help.
Thanks
Chandler
83 XJS V12 MS V2.2