Here we go again. I have a 1999 F250 SD Crew. Recently had the stereo stolen, so I installed a new stereo. In the glovebox! Bought an IR repeater and mounted it in the dash: aim the radio's remote at it, and the radio works like a charm. Open the glovebox to change cds. Also added a Viper alarm while I was at it. Took some debugging, but everything worked like a charm.

For about a month.

Now I'm having what appears to be GEM issues:
- The wipers and radio work fine with the key in ACC position.
- Wipers and radio do NOT work with key in IGN condition (or engine on).
- A relay inside the alarm unit sometimes clicks at random, while truck is running. I think the relay is used for the door locks, because I disconnected the lock wires from the unit, and the relay quit clicking.

Today I removed the GEM, cleaned it, and applied tune-up grease to everything before reinstalling it. Figured it's cheaper than a new GEM, and I can still drive it. Symptoms are exactly the same.

So here's my questions:
- Is this definitely a GEM problem?
- If so, where's the best place to get a new one?
- Does the GEM need 'programming? How do you go about having it reprogrammed? I hate dealerships, but I'll go if I HAVE to.

I've decided the 'central computer' concept of interior wiring is fundamentally flawed. If one expensive component (the GEM) goes bad, all sorts of stupid things start happening, and they're impossible to diagnose (FSM says 'replace GEM' for virtually all wiring issues!) In the old days, when the door locks weren't working, you could investigate the, uh, the DOOR LOCKS! Now, the door locks not working could mean your framistaner valve is sticking, or your flux capacitor is losing charge. WTF? The GEM is simply not a good design concept.

Rant complete.

Thanks everyone!

c.

 

I think it's an issue with the wiring, the gem should be more erratic than works on acc and not on run. Have you tried unplugging the alarm and trying everything?

The GEM will most likely need to be reprogrammed.

 

Thanks ReAX,

The thing is, if it was the wiring, I don't think it would have worked FINE for a month or so. I solder and heatshrink my connections: it's not likely one went bad. At first I thought it was a bad relay, but after replacing each one with no change in symptoms, I cast my eye toward the GEM.

The reason I suspect the GEM is from searching here: lots of folks have had erratic behavior due to a faulty GEM, particularly the radio, wipers, and door locks. I dont' think mine got wet, it didn't look like it had any corrosion or other physical problems.

If I HAVE to get a new GEM, I can deal with that. It'll really chap me because I think it's a bad design concept, but hey, I can't very well ditch it and buy a Tundra tomorrow. Even though I really want to.

I'm open to suggestions all around: thanks for the reply, and I'm gonna go back over the wiring again too...

c.

 

While your in the dash, I'd look at the ignition switch too. I haven't been into mine, but my old F150 had a rod into a switch, and that switch and rod were given to some odd behavior. If it's not making full contact on run, it could stop power from going to the radio/wipers. Just shooting ideas off here, the GEM is a nice setup if you have the tools to use it. If you had a J2534 pass thru connector, you could talk to the GEM and see if it's communicating with all of the other systems and what signals it is receiving.

 

Now I'm pretty sure it's the ignition switch. The slider thingy under the steering column. Unbolted it and slid the pin back and forth, and the truck had exactly the symptoms. What a relief! A $30 fix instead of a $300 fix!

Looks like Motorcraft makes a replacement unit. Is it something local auto parts places will carry? I need to get new brake rotors and caliper rebuild kits tomorrow anyway: took one front wheel off to see what kind of rotors I have, and discovered the brake pads were, well, gone. Plus the rotor is under minimum thickness. Figures: I've neglected it too long, it's my own fault.

Thanks again for the help!

c.

 

Yep, if it had a rod that goes up the column it's the ignition switch. Most places will have something, motorcraft and standard should both sell them.

 

Okay, now this thing is workin' my last nerve...

Tonight I replaced the ignition switch: the slider switch on the bottom of the steering column. Zip. Nada. Zilch. Exact same symptoms. So I hooked up my ODB-II code reader: got it for Christmas, still not sure what to do with it. I got this code: P0603, PCM Keep Alive Memory (KAM) Error.

Did a search on 'P0603', and got, well, two things: jack, and $hizzle.

Cleared all the codes I could find to clear (everything else was good, i.e. 'Pass, no codes found'), and tried again. Same shtick: wipers and radio work on ACC, nothing on IGN.

This is really chappin' my hide. I would like to listen to the radio on the way to work: I don't think that's too much to ask.

Any suggestions welcome. Use of firearms/heavy artillery has not been ruled out...

Thanks!

c.

 

KAM errors are either tied into another system, like the A/C pressure switch on older trucks or are a power problem.

Just for giggles, have you tried disconnecting the battery and turning the head lights on?

 

I disconnected the batteries overnight, just to see if that might reset something. Nada. What's that about the headlights? Disconnect the batteries, then turn the headlights on? Will that drain the residual juice out of the system? I'll try anything at this point!

c.

 

Yes, the head lights will suck out residual power, it makes a reset quicker.

 

Okay, I've just about decided it HAS to be the GEM. There's a local 'Auto Electric' place that can diagnose it for sure, but at $100/hour I'm not sure it's worth it: I'm pretty sure they are gonna find out what I (think) I already know.

Where's the best place to buy a new GEM? Any FTE sponsors carry it?

c.