How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ron Your Own Question
Ron
Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 35289
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
7276279
Type Your Ford Question Here...
Ron is online now
A new question is answered every 9 seconds

88 351 Bronco, Don't think I'm getting power to the fuel pumps.

Customer Question

88 351 Bronco, Don't think I'm getting power to the fuel pumps. Checked the rail external pump out side the truck with power and it runs. The relay clicks on when the ignition is turned on and times out after 5 sec as it should but no power to the pumps.
Submitted: 2 years ago via CarComplaints.com.
Category: Ford
Expert:  Ron replied 2 years ago.
Hello and thank you for your question, My name is ***** ***** I will assist you today.
Are you getting key on cranking power in and out of the inertia switch?
Customer: replied 2 years ago.
Hi Ron, I only checked to make sure the inertia switch had not tripped. The truck quit while driving 30 mph and no bumps in road.
Expert:  Ron replied 2 years ago.
Can you take your 12 volt test light and or volt meter and see if your getting power in and out of the inertia switch while cranking the engine and post back with the results s we can work from there?
Customer: replied 2 years ago.
OK but it will take a little while before I get back to you. How do I reach you.
Expert:  Ron replied 2 years ago.
Take a long as you need, all you need to do is return to this question, Im here all day.
Customer: replied 2 years ago.
OK
Expert:  Ron replied 2 years ago.
Im here when you ready.
Customer: replied 2 years ago.
Ron, I have 12 volts at the inertia switch when the switch is turned on.
Expert:  Ron replied 2 years ago.
Okay that's good noe do you still have it on both wires while cranking the engine?
Customer: replied 2 years ago.
Ron, when the black an red lead are plugged in to the in inertia switch, I get no voltage on either wire. When I unplug the two leads and read voltage to ground I get no voltage on the red lead and 6-9 volts to ground on the black lead.
Expert:  Ron replied 2 years ago.
The wires at the inertia switch should be brown (power in from the FP relay) and pink black out to the pumps. Both wires need to have power (12 volts) while cranking the engine, do they?
Customer: replied 2 years ago.
No. I read voltage when the inertia is unplugged. I lose it when I plug in the Red and black wires. I only read voltage on the black wire while cranking the engine and disconnected from the inertia switch.
Expert:  Ron replied 2 years ago.
You need to plug it back in and check the voltage at both wires while cranking the engine over.
Customer: replied 2 years ago.
I have but no voltage then.
Expert:  Ron replied 2 years ago.
Okay the power to the inertia switch comes from the Fuel pump relay, go back and check and see if you have power at the relay on the red and yellow wires out of the relay and a good ground on the tan/green wire while cranking. If you have all three then the brown power feed wire out of the relay should power the inertia switch. See if the red and yellow wires are hot with the key on and post back.
Customer: replied 2 years ago.
Ron, I think we found the problem. How about a fuel pump relay with an open holding coil. No continuity check through the coil and when 12 volt applied to the coil, no click. I'm off to buy a new relay.
Expert:  Ron replied 2 years ago.
As long as you have power on the red and yellow wires and the ground on the tan/green from the PCM while cranking then that may be the cases. Let me know and we can work from there.