No start, no crank, no dash lights after battery disconnected

[JohnDenver]

On my 98 Suburban k1500, I had blower motor/resistor issues that I started working on about a week ago. Ran into complications of course and the battery was disconnected for the week. Now today I got everything tied up and it won’t even try to start. Battery was strong before disconnecting. When I turn the key gauges move but no dash lights come on. Under hood light and map lights work but are really dim—almost orange. I did try a jump for a bit to rule that out with no change. As I was searching a bit, Passlock anti theft came up but I wasn’t sure if this sounds right for that since I’m not getting a security light or having it turn over at all. Any thoughts??

To give as much as possible to work with, I did have the dash front trim off to check the back of the HVAC switches. Also, vehicle has a strange (and I assume intentional) anti theft system that came with it when I bought it used. It won’t start unless left turn signal is on. Any of you ever hear of this type? Also would this conflict with Passlock?

I’m not 100% sure if PL was on all 98 models or how to tell if I have it.

Thanks in advance for any suggestions. I’m definitely a novice at electrical stuff.

 

[Erik the Awful]

Battery terminals have to be clean and tight, at both ends. That's what you need to check first.

 

[JohnDenver]

Battery terminals have to be clean and tight, at both ends. That's what you need to check first.

Terminals seemed good and other than the negative at the battery I don’t think should have changed this week. I did double check the negative and tried rotating it a little to see if I had a better connection. Am I missing something?

 

[JohnDenver]

Relating to the anti theft I mentioned, have this box near the driver side firewall that doesn’t seem all that integrated. I’ve wondered if it’s related to that system. Or if someone recognizes what it is.

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[Komet]

Check battery connections, mine has an extra ground to body right there at the battery so make sure you got all the grounds. Aftermarket anti-theft is always cause for concern. Check voltage at battery with multimeter.

 

[JohnDenver]

Check battery connections, mine has an extra ground to body right there at the battery so make sure you got all the grounds. Aftermarket anti-theft is always cause for concern. Check voltage at battery with multimeter.

Mine has the ground there also. I can try cleaning it up just in case. I probably should get a multimeter finally for this stuff. I keep debating how good of one to get and then not doing it.

 

[Komet]

Cheap is fine, most of the time you're only going to use it to find voltage and measure resistance which pretty much anything can do to an adequate level for car stuff.

 

[TCBRacer77]

I was waiting for someone to respond with “just hook the battery back up” due to how this post was worded lol

 

[JohnDenver]

I was waiting for someone to respond with “just hook the battery back up” due to how this post was worded lol

It almost feels like I didn’t but I double checked that.

 

[TCBRacer77]

It almost feels like I didn’t but I double checked that.

Lol sorry just had to say it hope things work out for you