Anyone know exactly where "g308" ground is? Its for the power doorlocks. As best as i can understand, it is in the left rear of cab, but thats kinda a big place, esp with a crew cab...

 

g308 is not comig up in the wiring diagrams as a good ground number in Ford's computer. Re-check the number and I'll try to find it.

 

it is indeed a G308 ground for an early 99 f350 psd crew cab with RKE.
I got the gound name/number from "Michel On Demand", similar to All Data at my college while im trying to find out why my door locks arent working correctly.

 

it is the ground for the doorlock switches, and the RKE relays. It says "Left rear of cab".
Looks like there is a ground splice S233 and S300 before the final ground

 

Ford is showing the ground to be G900 for power locks and RKE. Ground location is left rear corner of the cab just to the left of the backglass about even with bottom of glass according to the picture. Hope this helps.

 

G900, ok, well, i dont really care what the name is i just would like to know where it is before a tear apart my cab. Thanks jmorton!!

 

f350xlt460,

I have the exact same truck with the exact same problem. What made you think it is the ground. Let me know if it fixes your problem, I would love to get mine figured out!

 

ive done some testing at school (getting automotive degree at local college) with some friends of mine that are in a 2nd level electronics class (along with that prof) and have eliminated the motors. Seems like a power problem going to the RKE relay box (which is a pain in the BUTT to get too) or a ground.
My problem description:
My locks will try to work the first time a press a button (inside truck) and then they will try less and less the more i press the button. Always hear relays clicking though.

 

That's exactly what my truck does. The first time I hit my switch my locks might work but sometimes they won't. If I hit the switch more than once nothing happens but I can also hear the click. Let me know if the ground fixes your problem.

Thanks!

Bill

 

I've got the same problem...

1995 XLT CC

 

ramtruckman, change your name. LOL j/k, what is your trucks bdate? mines 1/98 (just wondering)

 

f350xlt460,

I've tried to change my name but can't figure out how (if you know how please tell me). I admit I had a 98 Dodge cummins before I bought my ford and while I did love the cummins engine I didn't like Dodges poor design on their four door truck. My ford was manufactured 6/98. Have you got your locks to work yet?

 

Is the relay passing a ground or a +12 to the locks? Put your voltmeter leads across the 2 wires that the relay is making and breaking, when the relay is not energized, you should read battery voltage. When you hit the lock button and energize the relay, the voltage across the relay contacts should drop to zero. Make sure you are measuring the contacts of the relay and not the coil wires.
If the voltage does go to zero, the relay contacts are fine and there is no voltage drop there.
Maybe the relay is making and breaking the +12 and the ground in which case, check both sets of contacts the same way.If either measurement with the relay energized is greater then zero, you have a bad relay contacts or one of the wires connecting to the contacts has a bad crimp or something.

 

Looking at schemes; the only relays in the pictures are for KeyLess entry. I think what you are hearing is the door lock motors (solenoids) trying to actuate. Question, does it do the same thing with Driver and Passenger doors?
Without Keyless entry: If it is only the driver door, it is mostlikely the switch. If it is on both of them, then check the 12V coming in to the switch from fuse 26, (99 PSD cc). If that voltage drops when switch activated, it not the switch or ground. If it stay the same, more or less, then it is the ground. May be able to remove and reconnect connector, may actually have to trace out.

with keyless entry, it gets interesting, three relays, one is driver unlock, all unlock and all lock. Do the doors Lock with Keyless entry and not the door switches? Driver/passenger door not work or Both. In this setup each switch is grounded, chassis somewhere, seperately. If they do not lock with keyless, switches are okay, relays are inline before switches. Problems lies somewhere between fuse 26 (20A) and power to the relay module. Or the contacts in either the all lock or all ulock relay are bad.

Need to know if you have Keyless entry and if CC or Two door. Can post Schemes and explain better.

 

i have several schematics and it seems that the relays and switches are all grounded at the same place, in the left rear of the cab. Ill find the ground tomorrow and investigate further.