if 2 hours of dome light killed the battery the battery needs replaced. Doesnt neccessarily mean the allternator is bad though. Are you really going to sell your truck cuz it needs a battery and an ignition switch???? Heck How much do you want for it?

These are all common issues for blazers.

 

Update - Just replaced the ignition switch today, fairly simple... I had to also transfer all the alarm/remote start wires to the new switch, and the truck actually started up with no issues and the alarm functioned properly.

OUCH!!!

Problem came back as it only ran about 5 minutes then stalled (still had dash/radio lights, etc), started right back up and ran about 3 minutes and stalled (still had dash/radio lights, etc), started back up for the 3rd time and ran about 3 minutes and stalled (still had dash/radio lights, etc). Get this! It may just be a coincidence, but rite when it died the last/3rd time I was wiggling the plug for the ignition module, and since then I could not get it to start again.

It also killed the battery, so I put in on the charger and tried to start while checking for spark at the plugs, but no spark, at the coil there wasn't any spark either. Not sure how to check the ignition module, but that is inline before the coil gets it's juice???

Suggestions?

 

3 minutes doesn't correlate to anything really. You must have done the security relearn. Did that take properly? Wonder if something in the passlock system is failing after the truck has been started. If you turn the key to the RUN position, but do not start the truck and wait for the security light to go out, then try to start it, will it stay running?

 

Hi swartlkk, I didn't do the passlock process, but as I type I have the charger connected to the battery, and the key in the on position (after the start attempt), but the security light doesn't stay on, it only flashes during the initial starting, but then goes away and only the SES and seat belt light remain on.

Here's what I got from a link in one of your older posts on this same issue.

PASSLOCK - Reprogramming Auto Learn
Passlock 30 MINUTE RE-LEARN PROCEDURE

1. Turn ON the ignition, with the engine OFF.
2.Attempt to start the engine, then release the key to ON (vehicle will not start).
3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
4. Turn OFF the ignition, and wait 5 seconds .
5. Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the PASSLOCK(TM) Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).
6. Start the engine (the vehicle has now learned the PASSLOCK(TM) Sensor Data Code and/or password).
7. With a scan tool, clear any DTCs if desired (history DTCs will self clear after 100 ignition cycles).
IMPORTANT: The vehicle learns the PASSLOCK(TM) Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
It is worth noting that it may take more than 3 cycles to complete the relearn and it does not necessarily take 10 minutes for the security light to shut off in all cases. You should cycle the key to OFF and back to RUN only after the security light has turned off. You are done when the security light turns off after a 10-20 second delay. You should then be able to cycle back to OFF and then start the vehicle.

 

I wonder if something with the bypass module for the alarm/remote starter isn't causing these issues. With a new ignition switch, the passlock system should activate the first time you start the engine, killing the engine within a few seconds of it starting.

 

I wondered about that too. The alarm/remote is as old as the truck. Had it put on within a month after I bought new in 99 by a friend (professional) that installs them on new cars at the dealers.

Another note to mention: When I first connected the ign. sw. I didn't connect the alarm, because I wanted to make sure it would start, and it did, but I turned it rite back off (didn't wait for it to die), then reconnected the alarm/remote wires and re-installed the lower dash stuff.

I'm lost now, but I may just have to go back under there and disconnect the alarm/remote start from the ign. sw. because I'm thinking they may be trying to control the security and possibly cancelling each other out, or something like that. I can at least see if I can get it to start and/or get the passlock/code relearn function done.

Heck, don't know what else I can do. I'll update asap.

 

Well... I didn't disconnect the alarm/remote yet, but I just tried the passlock relearn, but because I don't get the solid SECURITY light (goes off after the initial key on self test), it seems that it's not going to relearn, or maybe it doesn't need a relearn??

First - When I turn the key ON (w/o starting) I get all the dash lights including the security that I believe is a self test. Then they go away except for the SES and seatbelt light (NO solid SECURITY light), hence I am not able to do the passlock relearn.

Second - I tried to start the truck, but it didn't, and then left the key ON for the 10 minutes, then turned the key OFF for 5 seconds, and repeated 2 more times as the process reads, but doesn't start.

For what it's worth - I noticed a gas smell last night when I was messing with the truck, but thought it was my lawn mower cause it was close by, but I had put it back in the shed when I called it a night. When I was trying to start it this AM, I noticed the gas smell again and can clearly tell that it was coming from the truck, so it seems that I am getting gas through the injectors, but I thought I read somewhere that the injectors also shut down if the passlock feature was activated, but not sure. Regardless, I have to run out and will disco the alarm/remote when I return and post an update.

Thanks guys. Hope I'm keeping you all interested in this post, cause I think I'm getting closer.

 

What happens if you turn the key on and leave it on for 10 minutes, then try to start the truck. This 10 minute period should trigger the stock passlock system to deactivate and then allow the vehicle to be started.

 

Just tried that... Doesn't start.

Update - I disconnected the alarm/remote start (I only mean that I disconnected the wires that ran to the ign. sw. ONLY). Meaning there are other wires coming from the alarm/remote, but they are going under the center console, assuming they are for the heater/defogger/radio controls, etc., so I did not disconnect them. Heck there may even be more wires under there? What a pain!

So, after I disconnected the wires from the alarm/remote from the ign. sw. I tried to start it, and NO go. Again, I can smell gas, but still no start. I attempted to do the passlock relearn, but same issue. No SECURITY light (goes OFF after the initial self test). I then re-connected the alarm/remote wires back to the ign. sw. and tried to start, but NO start.

Starting to wonder if the ign. sw. and alarm/remote are fine, because I get the same results. Another thought... If I'm not getting spark to the ign. module/coil, could it be a different issue, because I am getting gas to the engine? Don't want to give up just yet, but if that's the case, then maybe this was never an ign. sw. issue?? Any more ideas??

Going back to the first time the truck first stalled, I lost all power dash/radio, everything. The battery also drained, which is why the ign. sw. sounded like the prime suspect, but not so sure now. I have no way of testing the ign. module or coil with just buying new and replacing them, so stumped again!

swartlkk (Kyle?), I think I found the problem. The truck has been running for a good 35 minutes without dieing on me. I really don't know how I could have missed this, but going back to yesterday after installing the new ign. sw. and just before the 3rd time it stalled I was wiggling the wires on the ICM and thought it was just a coincidence that it stalled (must of pulled the coil connector too). Well what I just did was removed the ICM and coil, and took them to Advanced auto and had them checked only to be told that they were fine. OK, I left feeling really bad and was thinking of how I could dump this truck and get a new one... Well that's not an option, so anyway I mounted the ICM/coil back on the intake and went to plug in the connectors and noticed that one of the wires on the coil connector was bent in a hook like fashion, but then continued to be straight (best I could explain it), anyway I pulled at the wire and it literally came apart... Could this be, I thought!... I can actually see the fried tips of each wire as though they have been making intermittent contact for some time... BLAH! BLAH! BLAH! (feeling stupid at this point). I then cleaned and reconnected the wire, plugged it into the coil and it started rite up!. No SECURITY light, nothing... Just running like a charm.

swartlkk, Hopefully I'm not speaking to soon, I have to say thanks for all your input, I learned a lot, especially that when something goes wrong, don't pass up the obvious (like checking wires) before you go out and spend hard earned money for parts that you really don't need. Thanks to everyone else for there input as well.
PS - Don't sign me off yet! I still have to put the under dash back together, so in the mean time. Thanks Again

 

Glad you found the problem. What stood out as odd is that you didn't have to do a passlock relearn... But as I said earlier, stalling after 3 minutes really doesn't tie it into a passlock issue.

Wiring problems can be a royal pain to diagnose and then to find & correct. Kudos to you for going over those things and finding the issue!