1999 Ford Explorer 99 Explorer fuel relay voltage drop

JCFOSHE

MEMBER
1999 FORD EXPLORER
6 CYL
AWD
AUTOMATIC
16,600 MILES

I have a 99 explorer that I purchased. They said the timing has jumped, so before pulling the motor I have changed the spark plug, fuel filter. It will hit and run a little off starting fluid. So I started looking at the fuel system. I noticed that the voltage going to the inertia switch is only 6.70 volts. I get the same volts at the fuel pump. I changed the relay and still get the same volts. I can jumper the power across and get 12volts and the pump runs. Why am I losing 5.3 volts through the relay?

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,645 POSTS

Have you checked for bad or corroded connections? Bad grounds can cause this too as well as a partially broken wire.

Let me know.

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Sunday, July 4th, 2010 AT 12:56 PM

JCFOSHE

MEMBER
2 POSTS

Why could it be a bad ground or broken wire when I can jump the hot over to the the post when I have removed the relay and can get 12 volts? It only drops when the relay is in place. Also the repair manual states when I turn the key on one post on that relay should have 12 volts for a few seconds then drop but mine stays on constant. Can I be having a pcm issue?