Mason Lefevre

I’ve got a 2002 f150 that was running just fine. I parked it outside for a couple hours and when I came back it would not start at first it was just the starter relay clicking. The battery is charged and there were no loose wires. The fuses have seemed fine so far. But here’s where it gets me. Everything starts going nuts the doors will randomly lock the hazards flicker and makes the fuse box click. But it doesn’t stop when I take the key out. So I disconnected the positive and let it sit for maybe 30 minutes and I go back out hook it up nothing comes on the dash I try to turn it over the alarm starts to quietly chirp and when I take the key out it gets louder. I stepped on the brake and it stops when I let it go it starts again. Does anybody know what’s going on

BareBonesXL

Have you owned it since new? Accidents, damage, recent work? Is it raining?

Search around the forums about GEM and EEC relay (EEC is no start condition, never mind). Seems to often be the cause of weird things happening.

Mason Lefevre

I bought it used and did a tranny swap about 5 or 6 months ago. It’s been running like a charm ever since. I haven’t worked on anything recently. No reckless driving or accidents. I just went and picked someone up parked outside for awhile.

BareBonesXL

https://www.f150forum.com/f6/relay-c...-flash-496995/

Mason Lefevre

Do you think it could have something to do with the viper alarm system

mike190

Sounds like a GEM (module) problem?

Jimboy

When weird electrical things start to happen it is often a bad ground. Attached is a list of grounds and their locations for a 2007 F150 4x4, yours should be similar.

I would take a look at G200, G202, G203 and G303 first, especially if you are a rust belt truck.

Excuse my formatting,
Ground Information 2007 F150

Designator, Location, Wiring Diagram, Page / View Page

G100 Ground at starter motor from battery 10-1,151-7, 151-9
G101 On firewall behind PCM 10-1, 151-3
G102 On firewall just Right* of PCM 10-1, 151-1
G103 On firewall near Right* fender 10-1, 151-1
G104 On Right* fender behind battery 10-2, 151-1
G105 Frame 10” below wiper fluid container 10-1, 151-1
G108 On Left* fender at air intake tube 10-2, 151-2
G110 On Left* fender at air intake tube 10-3, 151-2
G200 Behind parking brake KP (DS) 10-4, 151-12
G201 Under left center of Dashboard 10-4, 151-14
G202 KP (PS) near CJB (Fuse Box) 10-5, 151-16
G203 KP (PS) near CJB (Fuse Box) 10-7, 151-16
G206 KP (PS) behind & above CJB (Fuse Box) 10-6, 151-16
G300 DS rear cab area 10-7, 151-18&24
G301 DS rear cab area 10-7, 151-18&24
G302 Under front seat DS 10-7, 151-18&22
G303 Behind parking brake KP (DS) 10-8 thru 10-11, 151-15
G400 Under tailgate area DS 10-12, 151-20
G401 Above rear axle on left frame rail 10-12, 151-18&24

Ground Strap See Note 1. This is the engine ground

*Right and left are referenced to drivers view as sitting in driver’s seat not to be confused view from standing in front of vehicle

KP = plastic kick panel (needs to be removed for access to grounding lug) at floor level, Driver’s side (DS) or Passenger’s side (PS)

When checking ground connections be sure to grasp the wire and wiggle at the ground lug connection. There have been many reports of the ground screw being tight (cross threaded or bottomed) but the lug has not been captured causing an intermittent ground connection.

NOTE 1:

Ground strap see info at https://www.f150forum.com/f4/firewal...-strap-270837/
The ground strap that is located to the right of the PCM is connected to the back of the passenger cylinder head. There is a double threaded stud that is used to hold the heater tube to the back of the head. The ground strap is grounded there.

Steve83

Post pics of the battery terminals.

Jimboy

Mason Lefevre....,It’s been a few days since you last posted. Have you resolved this issue and if so, please post the solution? Feedback is important so that we all learn solution paths to these issues.

Thanks in advance

Jimboy

JCR 56

It's been more than a few days, more like two years ago.