DIsabling security start on 95 blazer

Our Blazer has some sort of security thing at startup.. the started won't engage unless you hit "unlock" on the key fob.. Anyone know if this can be disabled or something? Nothing in the manual about it..

It's only been annoying in the past, but now one key fob has quite working, which makes it impossible to start it with just the key.. Thanks for any help..

mac

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mac davis
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Wow.. Never even occurred to me that it might involve wiring... I was hoping it was a button sequence or something on the fob.. At best, it's annoying, but I guess it might prevent theft... Here in Mexico, nobody locks cars, so it would be nice to disable it.. Don't know how many times over the years that we've forgotten to hit "unlock" and have to hit it after the key is in the ignition.. lol

thanks, Bill..

mac

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Reply to
mac davis

I'll look in my manual set on the 95, But the alarm was an aftermarket (audiovox) on my 95. So it maybe a function of the alarm itself.

Cheers

Reply to
Martin Riddle

Sounds like aftermarket to me. The factory system simply locks/unlocks the doors and rear hatch.

Reply to
Steve W.

Thanks, Martin & Steve..

We bought it from the original owner, and he said it came that way... Since it doesn't have an alarm, I tend to believe him..

I have the original window sticker in storage (he kept it for 11 years).. I'll dig it out and see if it's mentioned.. I remember seeing suspension and trim group upgrades..

mac

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mac davis

Don't recall any GM system that worked that way, ever. GM used Passkey with a resistor chip in the key during those years. None of the systems required the remote to operate.

It may have come like that but it isn't factory. More likely something the dealer added.

Reply to
Steve W.

There is no alarm, Bill...

The fob just has buttons for "Door" "Unlock" and "Rear"... The back of the Fob says GM on it, and some numbers that are worn down... I'll have to see if my wife's fob is in better shape..

mac

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mac davis

I guess it's pretty common, Steve..

I told my wife that folks thought that it was after market and she said that all the tire and oil change places here (There are a LOT of Blazers and S-10's in MX) know to hit "unlock" before starting without asking her...

mac

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mac davis

Is this a Mexican vehicle?

I ask because I just looked at all my wiring diagrams from 93-96 for S-10 and S-Blazers US models and NONE of them show any connection between the key less entry module and the starting/ignition systems. The module itself is a stand alone unit that plugs into the wiring harness under the console or under the dash on the left side for most of them. I know the 94 that I had all the fob did was control the door locks and rear hatch. Same thing with my 97.

Reply to
Steve W.

No, bought it from the original owner when we lived in California, which is where he bought it new.. The fob has the same 3 buttons that you mentioned.. The truck has no alarm, just the annoying security feature..

If there is any reference to these, the back of the fob says: GM P/N 15955702 DOC / MOC 212 K1035 Model/FCC ID ABO o104T

Thanks, Steve...

mac

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mac davis

Well all I can say is you got me stumped. GM didn't set up the vehicle that way. I would bet that it has an aftermarket security add-on behind the dash panel. Sounds a LOT like a remote controlled vehicle immobilizer.

The only factory security for that year was the Passkey system that used a chip in the key to enable the starter. And that was an optional unit. Do you have a Security light on the dash that works?

AU0 - is the RPO code for the remote keyless entry. The module simply plugs into the harness above the panel under the dash.

The fob numbers you have are a factory 95-96 GM 3 button keyfob unit.

This may be something like what you have. Note that it connects to the factory system with 2 wires and requires you to hit the unlock for the vehicle to start. Would be simple for a dealer to add in and tack 150 bucks onto the price of the vehicle. Wouldn't show on the vehicles window tag or option list.

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USING EXSISTING FACTORY REMOTE (TX-21) - Factory keyless entry remotes can be used with the TX-21 secret circuit. The secret circuit is a wired transmitter that is activated when you unlock your vehicle using the factory or aftermarket alarm or remote entry system. The TX-21 installs in minutes with only a two wire hookup.

Reply to
Steve W.

Ok, Here is what is in my 95':

Alarm, Pursuit Series Model PRO 9230. (audiovox)

From the booklet: "When the system is armed the starter is bypassed."

So, if the system is not armed, your OK, you shouldn?t have to hit the unlock button on the fob. I think this is a misunderstanding by the grease monkeys at the garage. They hit the unlock to make sure the system is disarmed, even if it is not armed. I never noticed if it actually worked armed or disarmed.

Cheers

Reply to
Martin Riddle

Nope, and I don't remember seeing one in the manual, but I'll look again in the morning..

Yeah, that's what it looks like to me..

I'll check this out right now... Thanks, Steve..

mac

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mac davis

Nope, no alarm, martin.. When we test drove the truck, I tried to start it and no starter.. The owner said that you had to hit "unlock" before stating, even if the truck was already unlocked..

As far as he knew, this was a factory setup that he never asked for and didn't really like..

mac

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mac davis

Steve.. I checked that site and it looked possible but it only works on 98 and newer blazers.. I will look tomorrow and see if the starter relay looks aftermarket..

thanks again, mac

mac

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Reply to
mac davis

Don't go by that site. I used it to show you that what you have is easily done and not factory. Plus they don't list the vehicles that the X-21 fit, only the ones that the special relay they sell (which uses a separate remote) fit. The other item simply connects to the door controller and two wires from the steering column. More or less universal fit for any vehicle with factory remote locks.

I'm betting that your vehicle has a unit that works the same way BUT was installed by the dealer and likey is from a different company. All it really has to be is a simple latching relay, Break the factory wire going to the starter relay. Then the relay jumpers the break.

When you hit the unlock button it sends a pulse to the relay latching it closed. You hit the key and the engine starts. The capacitor discharges in the relay and the relay opens. Repeat every time you start the truck.

Pull the isolator panel over the drivers foot well and you will probably find a small module with wires that connect between it and the door controller and two that go to the area of the steering column.

Reply to
Steve W.

Thanks, Steve.. I'll see if I can find that tomorrow.. I'm guessing that it will look added on.. My wife seems to think she remembers what storage box my shop manual is in, maybe she'll dig it out tomorrow, also..

I'm guessing that I can get a replacement fob and just live with the starter lock-out, but I'd rather get rid of the lock-out if possible..

mac

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Reply to
mac davis

The fobs are all over the place Ebay has a ton of them all the time.

The unit will probably have a tag on it with a company name and part number on it. Then it may have nothing but a few wires coming out. Shouldn't be hard to find though.

Shouldn't be hard to eliminate it either.

Reply to
Steve W.

I thought that the dealer had to program them or something, don't they?

mac

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Reply to
mac davis

No. Fobs can be owner programmed. Just need the new fob and the current fob and the proper procedure.

Drop the under dash panel. Right next to the parking brake mounted on the panel is a module. This is the keyless entry module. Ground the black wire with the white stripe. The doors will lock then unlock, and the hatch should pop. Press lock on each remote one at a time. The doors should lock / unlock to confirm the remote(s) programming. Remove ground from black/white wire.

Reply to
Steve W.

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