Gem module failing?

[KornTruck2]

So i think i got a truck with a bad gem. I got basic functions like window up/down, power door locks, but no ding from the key, no ding when you leave the lights on, i dont have any interior courtesy lighting amd my wipers dont work along with the washer pump. Does anyone have a gem module pinout for a 2003 2.3 ranger? I took these pics amd i been looking through a bunch of random gem wirings i found looking for similarities. I checked things like the fuses and relays. I have a bi directional scanner. I was able to basic commands like command parking lights, headlights, power door locks, when i tried to get into the GEM module, my scanner acted like it was “gone”. I found a gem module online, i got it for cheap. I am sorts hoping its something along that lines. Any help would be stellar.

 

[RonD]

Does the Door Ajar light on the dash come on when drivers door is opened, if not then that could be the door switch is bad or unplugged, so no chimes, and no lights when door is open

Does door ajar light come on with passenger door open?

Does the dome light work using dimmer wheel all the way up?

Wiper/washer issue is more likely to be Multi-function switch, but could be GEM

 

[clarkbre]

The failure points you mentioned certainly sound like a failed (failing) GEM. I had similar symptoms in my '98. The dome light wasn't working with either door open and it wouldn't come on via the dash dimmer switch rolled up. The electronic portion of the 4wd was completely non-functional with the dash lights never lighting and no response from the system. After diagnosing what I thought was the GEM, I sent it to Module Experts (www.moduleexperts.com) and they determined it was dead. I purchased a replacement from them and upon plugging it in, everything worked properly. If I recall, the GEM also controls the speedometer, odometer and cruise control function too.

 

[RonD]

Just in 1998, 1999 and 2000 does the GEM do speedo/odo, and of course without speed signal no cruise
Automatic would also shift differently with no speed signal

 

[KornTruck2]

Does the Door Ajar light on the dash come on when drivers door is opened, if not then that could be the door switch is bad or unplugged, so no chimes, and no lights when door is open

Does door ajar light come on with passenger door open?

Does the dome light work using dimmer wheel all the way up?

Wiper/washer issue is more likely to be Multi-function switch, but could be GEM

The dome light does not work from the roll up nor the over ride switch. I took my scanner to my 99 ranger, i was able to get into that gem module no problem and commanded several commands based off the programming, door ajar, chime, wiper, courtesy lights and parking lights. When i did the same thing on my 2003 amd the gem module failed to connect. I kinda think i diagnosed this right. I found one same model number as mine and got it on the way. I think the remote needs to be reprogrammed for the new gem, but i thought that was cut and dry?

 

[RonD]

Yes, I would say GEM issue as well with that info

No, you shouldn't need to reprogram Key Fobs, that part of the system is done by the CSM(central security module), used to be called the RAP module
It is connected to the GEM but is a separate module above the glove box in 2003
It stores the Fob IDs and has the antenna

But yes, its not hard clear old Fobs and add current ones

 

[KornTruck2]

Does the Door Ajar light on the dash come on when drivers door is opened, if not then that could be the door switch is bad or unplugged, so no chimes, and no lights when door is open

Does door ajar light come on with passenger door open?

Does the dome light work using dimmer wheel all the way up?

Wiper/washer issue is more likely to be Multi-function switch, but could be GEM

so these inputs listed, i can check these input wires like dry contacts? I dont want to push voltage just yet. But i should be able to locate the door triggers, see if i am getting some signal from a few common points? I am still positive its the gem, wont be here for a week so i am just sitting and stewing

 

[KornTruck2]

When i got this truck running, the ac compressor kept going on and off. I ended up unplugging the compressor. My heater control was in its off position, and the ac
Compressor was shown to be on.

 

[RonD]

At the GEM the Door switches will show as Grounded when door is open, no ground when door is closed

Grounded Drivers door switch will trigger Door Ajar light and Chime if key is in ignition or head lights are on
Also turns on Dome light

On a 4-door Ranger the Drivers door has its own door switch wire to GEM
Other 3 door switches are all connected together to 1 other wire to GEM, so if any are open wire is grounded
This will trigger door ajar light and dome light but not the chime

AC doesn't use GEM
It does use PCM(engine computer)
AC compressor is active in all setting except OFF and VENT in a 2003
Cold or Hot settings do not matter, just the Mode setting

AC system is used to Dry the air in the cab winter and summer, so is always active unless OFF or VENT is selected on the Mode switch in the cab

 

[KornTruck2]

At the GEM the Door switches will show as Grounded when door is open, no ground when door is closed

Grounded Drivers door switch will trigger Door Ajar light and Chime if key is in ignition or head lights are on
Also turns on Dome light

On a 4-door Ranger the Drivers door has its own door switch wire to GEM
Other 3 door switches are all connected together to 1 other wire to GEM, so if any are open wire is grounded
This will trigger door ajar light and dome light but not the chime

AC doesn't use GEM
It does use PCM(engine computer)
AC compressor is active in all setting except OFF and VENT in a 2003
Cold or Hot settings do not matter, just the Mode setting

AC system is used to Dry the air in the cab winter and summer, so is always active unless OFF or VENT is selected on the Mode switch in the cab

So basically, i can find the driver side door wire, grab a meter, one side to ground, one side to the trigger. I should be able to close the switch and i should get tone?

 

[KornTruck2]

So the resolution for this was... drumroll.. at some point before i bought it, the back window was replaced. They lost the correct screws and just sent it. They put to big a screw in the connector thats clipped into the metal to isolate body ground from contact. I went to the junkyard and got a clean harness that i could solder in and i have not had any fuse issues since. This is basically what happened to that connector, just blew the f out of it..