bypass alarm on 03 yukon denali?

Before I start, please accept my apologies if my subject heading was poorly worded.

Here's what I'm trying to figure out:

I'm the second owner of a 2003 Yukon Denali. The original owner said he had the Clifford RSX 3.5 alarm system installed when he first bought the car. He wasn't 100% certain, but he thinks it was installed by the now defunct "Good Guys" electronics store. Fortunately, the alarm system seems fully functional.

So why am I writing? Here's the issue:

Ever since the original owner could remember, the OEM navigation/clock radio occasionally exhibited odd behavior: It randomly resets itself to Central Time. (Both the original owner and I live in the Pacific Time zone.) So, if the local time was 04:27 PST, then the new time would be 06:27 CST after the issue occured. The original owner tried to get the dealer to fix this issue, but not surprisingly, the dealership was unable to duplicate it.

I've owned the car for just over 2 years, and I've witnessed this behavior at least a dozen times so far. When it occurs, I also noticed that navigation setting for "auto update clock" gets changed from NO to YES. So, it seems as if the nav/clock radio resets itself? The only consistent behavior that I've noticed is that this issue seems to only occur when the car is parked outside overnight during the colder months.

I'm sure this sounds asinine, but I have a hunch that my Clifford alarm might have something to do with my nav/radio issue. To rule this out, I'm wondering if there is a simple or straightforward way to bypass or completely disable the alarm system? If the issue continues to occur when the alarm is disabled, then I guess this would confirm that my alarm has nothing to do with my nav clock issue.

If you have any other ideas/advice/suggestions, I'd greatly appreciate if you could share them with me. Just for the record, my knowledge/competence with car electronics is practically nil, so ANY feedback is actually appreciated.

Thanks for your time.

I have seen some odd behavior with some bypass modules hooked to the GM data bus. Most problems were resolved by simply providing a better ground to the module. This is not to say that the module is the cause of your specific problems. But it is very simple to check, take a look at the OBDII connector under your dash. There should be a wire soldered to the purple wire located at pin 2 in that connector. This is how the alarm system 'talks' to your truck. If you disconnect that wire the alarm will no longer be tied into the GM data bus and should eliminate the bypass as your problem. I would also suggest you put your alarm into valet mode prior to disconnecting the wire and do not use your system until the wire is reconnected. Without that wire connected your remote start, door locks, factory alarm arm/disarm, etc will not work with the Clifford remotes.

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Installer, IT support, and FFL. I need less hobbies.

Twelvoltz wrote:

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I have seen some odd behavior with some bypass modules hooked to the GM data bus. Most problems were resolved by simply providing a better ground to the module. This is not to say that the module is the cause of your specific problems. But it is very simple to check, take a look at the OBDII connector under your dash. There should be a wire soldered to the purple wire located at pin 2 in that connector. This is how the alarm system 'talks' to your truck. If you disconnect that wire the alarm will no longer be tied into the GM data bus and should eliminate the bypass as your problem. I would also suggest you put your alarm into valet mode prior to disconnecting the wire and do not use your system until the wire is reconnected. Without that wire connected your remote start, door locks, factory alarm arm/disarm, etc will not work with the Clifford remotes.

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Thanks for the tips! Hmm.... At this point, instead of trying to disconnect the wire soldered to the purple wire and waiting for my funky nav/clock radio issue to recur, I'm wondering if I should just work towards providing a better ground to the module (and wait for my funky issue to recur). What are your thoughts?

Oh, and I'd also be incredibly grateful if you could spell out how people improve the ground to their modules. I'm such a dummy at this stuff that my initial impression is that hook up a really thick copper wire between the module and my truck's frame!

If you don't have time to explain, no worries--I can certainly google various key words until I think I've figured out a way to achieve your tip.

Thanks again.

The existing ground wire is probably fine to re-use...If they used a ring terminal and crimped then attached to vehicle with a screw...Then check the ring terminal for over/bad crimp...Same thing for where they screw is...Make sure it wasnt over-tightened and damaged the ring terminal...You say it only happens over night and when it is really cold...Maybe it is a voltage issue...Load test the battery...etc...Does it have any au- in for ipod etc on the truck...?

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M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

tommy... wrote:

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The existing ground wire is probably fine to re-use...If they used a ring terminal and crimped then attached to vehicle with a screw...Then check the ring terminal for over/bad crimp...Same thing for where they screw is...Make sure it wasnt over-tightened and damaged the ring terminal...You say it only happens over night and when it is really cold...Maybe it is a voltage issue...Load test the battery...etc...Does it have any au- in for ipod etc on the truck...?

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Oh, I should have mentioned that I already had the battery load tested, and they found no problems with it. As a matter of fact, I went into the store with the intent to buy a new battery, but they convinced me not to after they performed a load test and checked the date on the battery. (The battery was 2 yrs old when they tested it.) No ipod input. Not sure if this matters, but the previous owner wired in a cheapie backup video camera that turns on when the car is in reverse. However, I have to plug a little LCD module into the cigarette outlet in order to see anything. Do you think this could be messing with my nav/clock radio?

Just checked the battery: Shipped date is July 2007.

Forgot to also mention that there are no other aux inputs that I know of.

One more thing: Considering my car always fires up right away when I try to start it, does this rule out any battery voltage issues I may be experiencing?

I was wondering if I could get your thoughts on the violet/white wire in my installation. (I've removed the electrical tape so that I could inspect the condition of the connection.) Follow it towards the engine on the lower left side:



A couple close-ups:





What do you guys think? Is this considered shoddy workmanship, or is this satisfactory? Do you think this could explain why my nav/clock radio randomly resets itself when the car is parked outside overnight in colder weather?

I could be wrong, but I think that plug is an ignition coil, and the violet/white wire is the tachometer input.

Let me know your thoughts.

That'd be the tach wire. Tach being a read only wire that would have NOTHING to do with the issues you are having. It looks soldered. At least they cared enough to solder.

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A DMM is a beautiful thing.

MECP Advanced Installer Certified.

No....it would not cause your problems. That wire is an input wire. They loomed it, and soldered....couldn't ask for much more.

Probably could have attached the wire a little better...Its hard to see...But from the pic it looks like they just laid the wire and solder...but again at least it was soldered,taped and loomed...Not the best work...as david said...At least they soldered...!

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M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!