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Pavlin Koev
Pavlin Koev, CERTIFIED TECHNICIAN
Category: Ford
Satisfied Customers: 3483
Experience:  17 YEARS HANDS ON EXPERIENCE, TRUCK&COACH TECHNICIAN LICENCE
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2003 ford expedition: wont start..fuse box..6 big relays..ran fine

Customer Question

2003 ford expedition wont start. buzzing fuse box, happened before. when it happened before rotated 6 big relays and it started ran fine for a year. just now doing same thing, tried the relays again, didnt work this time. tried #102, and #101 fuses. still didnt work.
Submitted: 5 years ago.
Category: Ford
Expert:  Pavlin Koev replied 5 years ago.

Pavlin Koev :

Hi and Welcome to JustAnswer! My name is XXXXX XXXXX I will do my best to help you with your vehicle trouble.

Customer:

okay

Pavlin Koev :

buzzing relays is sign for low voltage.

Pavlin Koev :

check battery cables, pull hard on them.

Pavlin Koev :

if cable moves tight it and recheck.

Customer:

what does that mean ? low voltage to relays? I tried the #101, & #102 fuses, when I took #102 out the buzzing stopped.

Pavlin Koev :

do you hear a clicking as you try to start. are head lights bright when you turn them on?

Customer:

headlights fine, but when I turn the key to start position I can feel a click in fuse box but not at solenoid. The dash lights that would normally go out in start position are staying lit as if the key is not turning

Pavlin Koev :

sounds like bad starter solenoid, use test light to check for power at small wire on starter solenoid, if you have power there at moment of key in start posittion starter is bad, if voltage is less than battery voltage, or no voltage there, then you have bad starter relay, wire from relay to starter, or fuse box corrosion which will result in bad connection.

Customer:

I jumped across solenoid and starter spins fine, I turned ignition on hoping to start truck and move to better spot, doesnt start.

Pavlin Koev :

check is signal from starter come to relay, you should get 12V when key in start,

Customer:

where is this relay I called ford dealership, they said there isnt one on this truck, still, if I jump and spin starter with key ON it should start shouldnt it

Pavlin Koev :

yes, just a minute to look at wiring.

Pavlin Koev :

Full Size Image

Pavlin Koev :

look at diagram, power comes to relay from ignition switch but goes through Safety neutral switch first.

Pavlin Koev :

try to start in neutral or as you keep shifting gear shifter as you are holding key in start position, if you are able to start, then safety neutral switch is bad.

Pavlin Koev :

Full Size Image

Customer:

all makes sense, but the red wire shown from battery to fuse box isnt direct is it?

Customer:

sorry i didnt see bottom half of your reply. I did try neutral switch ( turn key while in neutral ) nothing

Pavlin Koev :

red wire goes to fuse 101 and then relay -direct.

Pavlin Koev :

so when you test relay/you should have one battery power(always) and one coming from ign switch through safety neutral switch.

Pavlin Koev :

if you do not have power from SNSW- check you have power to it from ignition sw, on wire White and pink

Pavlin Koev :

if power goes to SNsw bot not coming out problem is there.

Pavlin Koev :

if no power at switch then possible ignition switch or wiring.

Pavlin Koev :

if power is at relay, but PCM does not send ground, wiring from PCM to relay or bad PCM

Pavlin Koev :

let me know if you need more help

Customer:

hot to relay and second terminal #85 gets power in start position. i can jump across #30 to #87 and turn starter still no start though. Does this sound like p.c.m.?

Pavlin Koev :

OK, it sounds you have problems with security system, thoes theft light flashes?