Gem Module

[lve2wheel]

Is the GEM module the grey box located behind the fuse block up against the fire wall? My radio and HVAC lights went out thinking the GEM may be going bad or got water water on it.

Or any other ideas as to why this might of happened.

It has an aftermarket radio, Completly powerless. HVAC controls still work but no lights. All fuses seem to be OK. havent checked relays or to see if I have voltage at the connector YET.

 

[bedrck46]

the gem module is the box that is connected to the rear of the fuse box

 

[bedrck46]

how did you check the fuses?

 

[lve2wheel]

I checked the fuses with a test light, vehicle keyed on so the radio and HVAC had power going to them. What does the GEM looked like (color, connectors?)? I tried peeking my head in there but its offely dark in there lol. Flash light wasnt very good.

 

[toms89]

Does not sound like gem issue to me. With gem issues circuits come on randomly when they are not turned on or even when the ignition is off.

I would suspect fuse. Not sure how you are using the test light. Are you able to check line and load side of fuse? Since its an aftermarket radio who knows what they tied the power into. Hopefully the original radio power wire.

If not fuse check power wire for break or bad connection. Check grounds.


To answer your original question the gem module piggybacks the interior fuse block. I removed my fuse block and gem module as a unit then they are easily separated.

 

[lve2wheel]

I just checked from ground. I didnt run the test light to power to check ground. (didnt have a long enough jumper) I've had the radio out before it was wired decently. Don't recall where the power wire was fed to. What about the HVAC lights? Do you think the problem is connected/related, Or a seperate issue? ( i know the controls so its not a huge issue but it would be really nice to have a radio again. )

And thanks for explaing where and what the GEM module looks like.

Long story short I purchased this vehicle back in 2011 in full working condition, Sold it to my ex (than GF) in full working order, and just bought it back with this condition. ( yes i love the truck that much) She claimed the HVAC light would flicker on and off for a while, than went black, worked for a min, than completly black again. And its been out ever since, So I thought that kind of sounded like the GEM issue you guys were reporting. ( i work 70-80 hrs a week so I havent really had to much time to dig into, My time is limited so all the Insight you guys are giving me is GREATLY appreciated)

Is there a relay for the radio?

 

[stamp11127]

To me the easiest thing would be to verify the fuses have power on both legs then back trace the radio wiring from the radio to the fuse block starting with the ground side of the circuit. If it isn't pulling power from the original radio circuit I would wire it so that it does.

 

[bedrck46]

one of the best ways to check under the dash is a good bright flashlight and a mirror.

Its amazing what all you will be able to see

the gray module that you referred to is most likely the security module you may even see 5 large numbers on it they would be for the key pad on the door if you have that option

 

[lve2wheel]

Ok so just went out there at work, the fuse WAS blown ( must have missed it some how), put another fuse in blew it instantly. Put a bigger fuse in and it works. So obviously I have a short somewhere I have to track down. Leave the fuse out for now and hope I can track it down during the daylight.

Now onto the HVAC lights. Could be part of the same wiring system, not sure yet.

Again thank you every body for your assistance.

 

[bedrck46]

according to the wiring print the fuse for the radio and hvac are the same fuse

check in the morning as I will see about sending you a copy of the print that shows the fuse

 

[stamp11127]

There is a flaw in your thinking - a dead short will blow any fuse you put into that slot - no resistance in the circuit so nothing to slow the current. If you have a 650 amp battery then it will attempt to push 650 amps through the circuit.

Since you put a larger fuse in and it didn't blow means one of two things. If the larger fuse never blows then there was more load on the circuit than what the fuse could handle - you install a 3 amp fuse but it needs a 5 amp and blows the fuse.
The second is a worn spot on the hot wire that intermittently does short to ground and will eventually blow the larger fuse or burn the wire in two.

What size fuses are you using?

 

[lve2wheel]

A wiring Diagram would be awesome Bedrck46.

Even with the new fuse in, still no HVAC lights ( and yes i turned the lights on to check), If those two are tied in together, that may be where the short is. In the HVAC wiring rather than the radio. Thats good info to know. Thanks again Bedrck46.

 

[lve2wheel]

What size fuses are you using?

The fuse block diagram I printed called for a 10 amp fuse. I put a 15 amp fuse in ( only one i had laying around), and it blew. So i pulled the 30 wiper motor fuse. It didnt blow. YET

 

[bedrck46]

prints

if you need any others let me know

 

[lve2wheel]

That should work perfectly. Thanks for those Bedrck46.

 

[lve2wheel]

Figured I'd give you guys an update. Went throw all the wiring for the radio which was actually done fairly nicely. I was able to track down a break in the wire on the factory wiring harness. wasn't completely broke yet but it was close. Must have been grounding out on something under the dash. Some splices, solder, and some heat shrink and wire loom good as new again. And went through all the wiring on the HVAC lights, everything looked great. Turns out both bulbs burned out at almost exactly the same time. Kind of wierd but should of looked at that first. MY BAD. Thanks "BEDRCK46" for the wiring diagrams, those helped a lot. Many thanks to you all.