no power to coil

freakasis · 09-28-2008, 07:06 PM

1998 contour 2.0L

i got no juice at the middle wire and no check engine light on when key is on. no power to the ecu or the fuel pump either. i checked all fuses (with a multimeter) and moved relays around(didnt actually check them, just changed them with other ones in the car) and nothing helps. i put power to the middle coil wire and the check engine light comes on, fuel pump primes, and the car will start.

any ideas? thanx

freakasis · 09-28-2008, 07:10 PM

not sure if this is gonna help any but the car has been sitting for like 4 months because suposedly the trans is bad. when the car did start as soon as i gave it gas it died, then after starting a few times it would just die aftger about 5 seconds without giving it any gas,(sounds like not getting enough fuel, it is on E) i do have a check engine light on after it dies but i dont have a code scanner.

theoldwizard · 09-28-2008, 07:27 PM

The "ecu" get power directly from the battery via the PCM Power relay.

Sorry I don't know exactly where it is located, but it under the hood.

BroncoJoe19 · 09-28-2008, 08:04 PM

Do you have a power distribution box under the hood?
Some times the maxi fuses under there control power to a couple or few fused circuits under the dash, IF you have your owners manual it should have a diagram depicting more detail

theoldwizard · 09-28-2008, 08:16 PM

Joe, you are going in the wrong direction.

The PCM and everything it controls (except the fuel pump which has its own power relay) get juice from the EEC Power Relay which is wired directly to the battery (probably via a fuseable link or one of those new maxi fuses).

freakasis · 09-28-2008, 10:22 PM

well i dont have an owners manual, and i tried swapping in relays that i know are good. i tested for power at both sides of all of the fuses, including the big ones (took the covers off and tested while they were plugged it). nothing.

where do all the wires from the ignition switch run? is there a separate wire for these systems? or they just get connected through the accessory option?

theoldwizard · 09-28-2008, 11:04 PM

If you know which relay is the EEC Power Relay then check for voltage at the pins.

KEYPWR turns on the EEC Power Relay which powers all of the EEC sensors and actuators (except for the fuel pump)

BroncoJoe19 · 09-29-2008, 04:56 AM

theoldwizard
I guess it varies from one car to another; if I am reading the wiring diagram for a '95-97 4.6L correctly, the ignition switch powers the coil directly, the EEC relay (at least the low amperage side), and the fuel pump relay.

Could it be that he has a bad ignition switch and when he puts power to the coil it is backfeeding the switch?

Or no power to the ignition switch, broken wire, or blown fuse that he missed, and it is being back fed?

freakasis · 09-29-2008, 07:06 AM

what is the "EEC Power Relay"? i dont remember seeing that. but when i put power to the coil at least one relay clicks, in the under hood fuse box.

im going to turn the key on and check for power at every ignition wire and then jump the coil and check them all again, and see if theres any differance. if there is a differance then it must be the ignition switch right? can someone tell me what all of the ignition wires do? theres like 6 i think.

freakasis · 09-29-2008, 07:09 AM

i do remember seeing like 4 of these. are you talking about the one that says "PCM power relay"?

http://www.partsamerica.com/ProductDetail.aspx?MfrCode=BOR&MfrPartNumber=R6026