New member + old truck + dead cylinder

Any chance this looks familiar to anybody?
There’s a little bit of hack job looking wiring under the dash, and I’m starting to wonder if the problem isn’t down there….

I’ve search around, and I don’t see anywhere for that big 24 pin connector to plug in.

 

Oh boy the mess of an aftermarket alarm. Have you tried leaving the key on on and disconnecting the battery then reconnecting? Usually with aftermarket alarms this will prevent ignition cut from the box

 

Trying it right now

 

Didn’t seem to make a difference. Although I have so much of the harness disconnected right now, I’m not even 100% if it could crank….

GUess I’ll go through and reconnect things

 

This is literally exactly what went through my head when I saw the box...

 

90% sure that box is your problem... just from experience. multiple times

 

I'll bet you guys are right.
I checked the starter relay fuse under the dash, and.... It's dead.

I'll start looking through the wiring diagram again, but I feel like if the problem was on the engine side of the harness, that fuse would still be powering up.

 

those alarm boxes cut power to ignition when they trip the alarm

 

That's my thought too.

I used to install Avital, Clifford, DEI, and not many years before your truck was born. In fact, close to the date stamped on the underside of that black box. But that specific box doesn't look familiar to me, I can't nail the brand down.

Best advice would be to untape the bundles and work your way back, connecting like-to-like, where possible.

However, if you want to be more metered, gimme some shots of any identifying details. I'll see if I can dig something up.

However, you may want to dig back thru EWD to see what wire colors you need to be hunting for in the IGN/starting circuits.

 

Hmmm.... Most everything else seems to be powering up though. Turning the key turns all the lights on, and even clicks the "pwr outlet" relay in the engine bay fuse box....

 

Yeah, I don't necessarily think the alarm is 100% your problem here, but it's definitely something you want to un-fuck out of the system so you know it's not part of the problem.

 

Appreciate that offer. I'll head back out and start working on unhooking stuff. There's also some aftermarket speaker wires under there, just to confuse things even further. But the radio doesn't work anyway.... So anything that doesn't look factory can just come right out.

And like you said, even if it's not the problem....
I definitely don't wanna be driving it, feeling like there's a ticking time bomb of some old alarm waiting to shit the bed

 

This is gonna be even more fun than I thought

 

Half of these wires aren’t even soldered or crimped. They’re held together with electrical tape and a hope

 

Typical for fly-by-night shops and DIY'ers.

Any chance you can pop the four screws off the bottom, take the top off and shoot a pic of the PCB? Looking for a specific model number on the PCB since everything is gone on the box. The oval sticker has a manf'er date to match what's stamped with the month/year circles embossed on the plastic, but the scratch-out, I can't make anything out of it.

What's got me scratching my head is these two white molex plugs. Note, they cut the blue wire in half, then spliced in a section of white wire. But for what? FML, that's some Homer ass shit right there.

 

what a mess! I used to install stereos and alarms too. In all honesty pulling shitty wiring and putting things back to stock is so satisfying these days for me. When I got my tundra it had some sort of alarm/ignition kill. It wasnt working anyway and not giving me any problems but it came straight out! lol

 

Well, so it looks like the whole alarm must have been partially removed/bypassed already. When I started yanking wires, it didn’t look like the factory harness was really cut any where and there was a lot of shit unplugged.

There’s maybe 2 or 3 wires that I’ll need to spend a little more time figuring out. Small plugs under the dash with nothing in them…. Two wires into the factory harness that don’t go anywhere…

That white splice wasn’t the weirdest thing I saw…. I’ve got wires into the headliner running out into the engine bay and things I can’t make any sense out of…

But I just cut out anything that didn’t look factory, and right now I’m still where I started.

Turning the key clicks, but no power to the starter relay.

 

the wires going to the engine bay are likely going to an ignition coil or a loud speaker for the alarm

 

That's one hell of a pile. I can't tell you what that box is, but if I had to guess, the green Rayex box on the corner is a relay, as are the 4 Siemens controllers if I'm not mistaken. The dip switches are typically what you'd use to configure the modules or alarm brain to suit the install. The fact there's only 4 makes me think this is a secondary or add-on module, full-on brains would have 10+ at least. Has me wondering if this add-on unit isn't a remote-start module, which is why it remained semi-wired.

That's my guess on this: The larger 24-pin connector went to the alarm brain, removed before you purchased. This smaller black box you just disassembled was a remote start add-on, and was left intact to avoid interrupting the starter wiring.

Given some of the corrosion I'm seeing on the corner of that board by C16, which I think is a ceramic cap, maybe it got wet at one point and shorted?

Again, you got me on this one.

 

Just a quick update for anyone playing along, I haven’t died, or given up…
But, working for UPS, the last couple months have been more than a little hectic. Now that I’m back to a 5 day work week, plus a little more opportunity for taking random days off, I’m gonna dive into it again.

I just finished rearranging my garage and I have just enough space to pull the truck all the way in and close the door. And I’ve got a big propane heater out there now.

The plan is to have it up and running, with new wheels, tires, suspension, bodywork and brakes by the summer. And road trip down to GA to bring home a small 5th wheel camper I bought from a buddy down there.

So hopefully I’ll have a real update soon

 

Awesome! I've plugged you a couple of times recently and meant to come here and post for updates but forgot. Got my own damn problems

Whereabouts in GA you planning to head, if I may ask? We've got a few members here.

 

Oh it’s way down there, not far across the border from Jacksonville.
Wasn’t looking for another project any time soon, but a buddy of mine was selling it, and he needed the money. So here I am…

As the tundra…. Anybody recognize these two wires? There the only real leftovers after I pulled out the remote start/alarm or whatever exactly it was.
Didn’t get much of a chance to mess with it over the weekend, but I did spend a little time poking around and remembering exactly how I left it…

 

@kirbotc can you confirm the colors on those are purple or violet w/white stripe and black with yellow stripe?

 

Yup, correct on both.

 

I do have some 'open' (unplugged) connectors in my truck. That single conductor black/yellow is interesting to me I'm less concerned about tht one, more worried about the purple/white. Have you consulted the electrical wiring diagram (EWD) for your year?

 

I have not yet.... I'll pull that up on lunch break tomorrow and start searching for it

 

Here's @RainMan_PNW 's collection of EWD: https://www.tundras.com/threads/ultimate-wiring-diagrams-collection.81448/

Legend:

 

Violet-white appears to possibly be the airbag detection? (1st pic)
Black-yellow is used in a few places, including a relay for the VSS and stuff in the cluster, "VTA" related to throttle position, tees off fuse block "10A GAUGE", and also from ECU to "Center and ignition coil No. 3" (of 8), and an EFI relay, at least.
Search the EWD for B-Y and V-W, I believe that's how I found.

 

Hmm, a few of the dash gauges don't work. So that might be part of it...
Doesn't sound like any of those are causing my main issue though.

Thanks so much for finding that though. Every time I start searching through wiring diagrams my eyes start glazing over.