QuestionRoland
this is a follow up question.
On my relay I have constant power to the red and white wires
Dark blue wires have power when key is turned on.
The blue with yellow stripe has power when key is on.
I also checked the relay to see if it would open and close
if I powered it up straight from the battery.and it does.
I do not here the fuel pump power up when the key is turned on.
I also ran direct power from the battery to fuel pump. the car started
the relay is new
I do not see any broken wires or bad fuseable links
any ideas on what could be my issue
thanks for your help
Derek
AnswerHi Derek,
The dark blue wire should have 12V on it when you turn the ignition switch to run, and it does. The dark blue/yellow is the key to activating the fuel pump relay. When you first turn the key to run it will show 0 volts (grounded) for about 1 second, then the engine controller will change that to 12V if you do nothing. That has the effect for the first second: of closing the relay, which causes the fuel pump to run for about a second. Then when you start cranking it will ground the blue/yellow wire again, closing the relay and sending 12V to the fuel pump for as long as you keep cranking it. So try those measurements. If you don't see the dark blue/yellow going thru that set of changes, then there is something wrong with the engine control computer (it would only fail to do that if the engine would not fire up, which is not you situation as you have proven by jumping to the fuel pump directly).
If it does go thru that routine, then you should see 12v on the dark green/black wire at the relay for a second and while you are cranking it and that wire is the one that goes to the fuel pump. If you see 12v on that wire at the relay but don't get fuel pump action then look for a black color 10-pin disconnect type plug inside the cabin on the cowl wall (to the left of the driver's left leg) where you will find that same wire on its way to the fuel pump. Check to see if you are getting 12V when cranking at that disconnect (maybe that is disconnected?). You should, and then it should appear at the fuel pump. Another way to check would be to measure the resistance between the dark green/black at the relay and at the other end (at the fuel pump), it should be around 0 ohm, not infinite ohm.
So try those ideas and please let me know.
Roland
