"eliminate the obdII factory security system

[dwragon]

Have you replaced the crankshaft position sensor yet? What about cap and rotor? Apologies if you have, and I didn't catch it. But on my Burb, when I had a "crank, no start" situation, those things fixed it. This was before the passlock went crazy though.

No, I havent been working on it enough to get that far, though I was just about to ask for most common recommendations. I got it to crank, have fuel to the injectors, haven't removed any plugs to see if they are wet yet, charging the battery now, I drained it trying the passlock reset/fuel diagnosing. The OBDII gave a zero RPM, so it may be the Crank Sensor. What is another indicator is that there are 2 ignition modules in the glove box???, makes me wonder. The history is supposedly the previous owner was driving down the street and it simply stopped running, he thought it was out of gas, then somehow lost the keys. got a cap and rotor, will put them on, looking for a crank sensor, and browsing a chilton.

 

[HotWheelsBurban]

No, I havent been working on it enough to get that far, though I was just about to ask for most common recommendations. I got it to crank, have fuel to the injectors, haven't removed any plugs to see if they are wet yet, charging the battery now, I drained it trying the passlock reset/fuel diagnosing. The OBDII gave a zero RPM, so it may be the Crank Sensor. What is another indicator is that there are 2 ignition modules in the glove box???, makes me wonder. The history is supposedly the previous owner was driving down the street and it simply stopped running, he thought it was out of gas, then somehow lost the keys. got a cap and rotor, will put them on, looking for a crank sensor, and browsing a chilton.

Could be so many things,on a truck this age. My personal experience with my Burb,99 5.7 Vortec, is what I'm quoting.
On our other 99 Burb, we never had issues with the passlock, but I may have replaced the crankshaft position sensor. I know I did cap and rotor on it. We bought that one in 2005, and it got totalled in 2012, so my recollections are a little faded.
On the current Burb, I put the Blue Streak rotor and the UMP vented cap on it about a year ago. Been happy with them. Before I started using the Blue Streak rotor, the truck was needing the rotor replaced every 6 months, with the cheap white rotors.

 

[dwragon]

Could be so many things,on a truck this age. My personal experience with my Burb,99 5.7 Vortec, is what I'm quoting.
On our other 99 Burb, we never had issues with the passlock, but I may have replaced the crankshaft position sensor. I know I did cap and rotor on it. We bought that one in 2005, and it got totalled in 2012, so my recollections are a little faded.
On the current Burb, I put the Blue Streak rotor and the UMP vented cap on it about a year ago. Been happy with them. Before I started using the Blue Streak rotor, the truck was needing the rotor replaced every 6 months, with the cheap white rotors.

Well, I replaced the cap and rotor, the coil, ig. mod., magnetic pu, put a small shot of either to see if it would rumble, nothing. only thing left is the camshaft sensor, or a loose wire. I know that the wiring harness is not like my 96, so I am wondering if it being a 3500HD, does it have a 98 wiring harness (finned cast computer out on the fender.)? Gotta get this thing running because the frame on my 4X4 split above the motor mount.

 

[Supercharged111]

When it's anti-theft, it fires then dies. A no start is something else entirely. Plus as mentioned you don't have anti-theft.

 

[dwragon]

When it's anti-theft, it fires then dies. A no start is something else entirely. Plus as mentioned you don't have anti-theft.

yes, I am working toward that direction. It "had" an aftermarket beepy/flashy alarm system, but it had been disabled. dont know if the chiltons is correct about a D18 circuit, going to see if its hot tomorrow. One of the biggies on this 97? truck is that the clutch switch has 4 wires, verses the two of my 96. Wondering if I bypass that will it start...

 

[Supercharged111]

yes, I am working toward that direction. It "had" an aftermarket beepy/flashy alarm system, but it had been disabled. dont know if the chiltons is correct about a D18 circuit, going to see if its hot tomorrow. One of the biggies on this 97? truck is that the clutch switch has 4 wires, verses the two of my 96. Wondering if I bypass that will it start...

That should only keep the starter from going

 

[dwragon]

That should only keep the starter from going

what does "that" refer to, and what would you look for that I haven't mentioned?

 

[Supercharged111]

what does "that" refer to, and what would you look for that I haven't mentioned?

The clutch switch prevents the starter from going at all.

 

[AK49BWL]

Four wires because two are for deactivating your cruise control (brake circuit I/O) and the other two are for activating the starter solenoid when you turn the key and press the clutch pedal. And those should be there on ALL GMT400s... I think the older ones had two separate switches where later models had single unit for both switches. My 93 had both functions, I at least know that much lol.

 

[dwragon]

Four wires because two are for deactivating your cruise control (brake circuit I/O) and the other two are for activating the starter solenoid when you turn the key and press the clutch pedal. And those should be there on ALL GMT400s... I think the older ones had two separate switches where later models had single unit for both switches. My 93 had both functions, I at least know that much lol.

ah, yes, Thanks, I had forgotten it had cruise, because I never use them (Mostly because they never work.). I usually bypass the clutch switch because I grew up without them and they are to me a PITA (Had them cause a no crank situation in the past.), but I wont bypass the cruise interrupter. going over the wiring harness today with a fine tooth comb, I found some major corrosions yesterday, even in the fuse box. This truck was from N. Dakota and has surface salt corrosion on everything, even the grounds at the thermostat housing. hoping that is it and I will find it. Later plans are to transfer the 3500HD cab/ front end to an unrusted pace arrow RV or UPS box van chassis. I have fallen in love with the extended front bumper, as it is at perfect step height when crawling up to work on the engine. Wondering how a diesel bumper would fit...