Interior lights/radio stay on...?

[chrisinkanata]

Three weird, obvoiusly related symptoms lately.
1 - Shut my '02 D/A crewcab down with the radio on and then open the door, the radio stays on. Most often it will not turn off. That's been going on for a while. Further, sometimes the dome light comes on and at other times not when you open the door to get in.
2 -Now over the weekend, I look out at the driveway Thursday night and notice the reading lamps on in the truck. Went out, turn them on and off manually, they stay on. Start the truck, shut it off and everything works properly again. All interior lights shut off after 15-20 seconds.
3 - Go out this morning to leave and the truck won't start. Clearly the batteries are close to dead. Other than starting it on Thursday night, it hasn't been driven all weekend, so although I checked the lights once or twice and they weren't on, at some point they came on again draining the batteries to the point where it won't start after a round of glow plugs (-18C here last night).

Any thoughts....????

Thanks,

Chris

[trbankii]

I'd start by checking out the door switches - easy to get to and fairly cheap to replace. Since there is a delay on things switching off, it isn't directly wired from switch to light - some sort of "computer," timer, or such between the two - which will be more expensive if that is what needs to be replaced. But if the switch isn't telling the "computer" that the door is open or closed that is the start of the problem.

The only thing that doesn't make sense is the reading lights not working manually - that seems to point more to the "computer" end of things.

[DmaxMaverick]

On late models, the "door switch" is integrated into the door latch. The BCM circuit is the RAP (Retained Accessory Power). It is controlled/timed by the BCM, and has a relay (underhood power center--fuse box). If it were only the lights staying on, I'd suggest a problem with the door latch/switch. But, because the radio is also coming/staying on, it points to the BCM or RAP relay. An ignition cycle with the door latch switches closed needs to happen to activate the RAP. The relay could be really sloppy (failed), making intermittent contact, but it is doubtful if the truck is sitting still (no vibration or impact to cause it to make contact). That leaves the BCM. Ideally, you need a Tech II attached at the time this is happening to see what is being commanded. If the BCM is commanding RAP with no ignition cycle, the problem is the circuit between the ign switch and BCM. If it is not commanding, and still activating the RAP, then it is the relay circuit. Very difficult to diagnose w/o a scanner capable of reading the real time state of the BCM. Pulling the RAP fuse and/or relay when you are not using the truck should prevent battery drain while it sits, until you nail down the cause. And, pulling only the RAP fuse/relay will not reset the radio clock/settings, seat memory, and other full time volatile powered accessories.

I'll check the diagnostic steps in the service manual. If there's more than what I've already posted, I'll get back to you.


[Correction]
The RAP-1 relay is located in the fuse panel in the cab. It is labeled on the cover diagram. Same for the fuse. The RAP-2 relay is located at the instrument panel junction block. I'll have to look further to determine which circuit could effect the system like it is.

[DmaxMaverick]

OK. Had a look at the diagnostic steps for your symptoms. Pretty basic, really. Only 3 options for repair, in order of cost and simplicity:

1. BCM, RAP relay or related harness connections. A poor (dirty or corroded) or open/intermittent connection can cause the issue.

2. RAP relay replacement.

3. BCM replacement.

Unfortunately, you need a scanner capable of showing BCM parameters to verify the timer actuates, counts down, and completes. If it restarts the countdown, then the BCM is suspect, and needs replacement.

One thing they do not include in the diagnostic steps, and I think could be related, is the ignition switch (a more common failure than all others mentioned here). If the ACC circuit is closing intermittently, it could cause the issue you are seeing. Without a scanner, I don't know how you will be able to "see" which direction the RAP activation is coming from.

Still, I suggest pulling the RAP relay when you are not using the truck to prevent battery drain. If, by some strange chance, the problem continues with the relay removed, that narrows the source of the problem, and would expedite a repair solution. The RAP relay is not unique. It is the same relay used for many other systems on your truck. You could replace it (they're not expensive at Napa, Autozone, etc.) or swap it with another system. If the RAP issue is resolved by this and the problem is then evident in the system you swapped with, that's an easy diagnosis. If you swap it, and the problem continues the same, you can eliminate the relay as the source. The RAP-2 relay (instrument panel junction block) should not be a factor in your diagnosis. It is a subsystem of RAP-1, and is not powered independent of RAP-1 (shouldn't be, anyway).

Let me know if you need any more on this. It's got my curiosity up.

[chrisinkanata]

DMAX...thanks for all the info. That's great!! The fact that a Tech 2 is needed simply means that I'll have to break down and take it to my dealer. Based on reading my manuals, I tried removing the RAP relay last night and no issue this morning. Started well...(and again -15C last night - not plugged in).

I'll let you know.

Thanks again.

Chris

[DmaxMaverick]

A Tech II may not be required. I just don't know if the Snap-On, Mac or other scanners are able to read the BCM. A local garage may be able to answer that (and they're usually much cheaper than the dealer). You should be able to trace it down with the material I sent you. First, I'd try switching the relay (there are several of the same relays in the underhood box). Switch it with the GP/heater relay, and if you get those codes, you can confirm the relay as the source. If the same issue continues, that eliminates the relay as the problem. Trace it back to the BCM, and if you don't find it, then it's the BCM. At any rate, it seems pulling the relay will keep it from draining the batteries. Temporary and inconvenient, but it won't leave you stranded.

[OhmEye]

OK, it's started happening to mine the last three days. The first time, it was a simple matter of turning the ignition back on and then off. Now, not so simple. I like the idea of fixing this by re-seating the RAP relay, or swapping it out if this doesn't work. My problem is that upon opening the fuse box I am realizing I might be blind! I can't seem to find the RAP relay. Might it be called something else in here? I find two different styles of relays. The larger ones are labeled PARK LP, STARTER, EDU, and the smaller ones are HDLP-HI, F/PMP, DRL, HDLP-LOW, A/C COMP, FOG LP, HORN,W/S WASH. Of course, I might be looking in the wrong place altogether. :rolleyes:

Back out to the truck to check.

[DmaxMaverick]

The 2003+ electrical is very different than 01-02. I don't know where your RAP control might be, but we can certainly find it.

Try disconnecting your battery cables (all 4) and connect one positive cable to ground for 30 minutes to an hour (be SURE both batt+ terminals are removed from the battery). This should clear the temporary memory from the computer(s). Sometimes it works, sometimes it doesn't. Either way, free to try....

[OhmEye]

OK, this sounds like it couldn't hurt. Just clear everything out altogether. A warm boot always does wonders for the computer here at the house. I like to keep it close to the floor just for this purpose. :D

I noticed two things when I got back in there. Bad news was mouse turds in the fuse block. Don't know how long they've been there, could have even been since it lived in Frazier Park. I looked for wiring damage, then blew everything out. We'll keep an eye out for return signs. I may have to duct tape a cat under the hood for a while. No problem finding one in this neighborhood that won't be missed. . .

The good news is that when I removed and replaced the 40A IGN fuse the problem went away and so far hasn't come back. Time will tell, but for now going to take your advice and put the truck into a deep sleep for an hour or so. Hey, it could even make the ol Jimmy forget its intermittent feelings of tire pressure monitor envy. Who knows?