Help! Swapped headunit, truck not starting. Immobilizer?

Like the title says, I just finished installing an Alpine headunit from crutchfield in my 02 (SR5 V8). Went in with no problem, checked to make sure everything worked before I buttoned it up. Got the panel back on, and now the truck will turn over and fire, but then immediately die. I'm guessing I triggered some kind of immobilizer, but google is letting me down on answers big time. Checked my fuses, everything looks fine. Anyone know WTF is going on?

 

I swapped out my JBL factory radio for an Alpine in my 06 and didn't have to do anything different to start it right up. Maybe try unhooking the battery for few minutes and hook it back up.

If you installed the

$280 Alpine ILX-W650 7" Double DIN Touchscreen Digital Multimedia Receiver with Bluetooth, Apple CarPlay and Android Auto

Alpine ILX-W650 with the touch screen post a pic or two. I'm thinking about upgrading to that unit.

 

Might have done this already but have you opened it back up and unplugged the headunit, then try to crank. Haven’t done a head unit, so know nothing about wires one may or may not have to cut ! Just a drive by thought !

 

Tried plugging the stock headhunt back in, leaving the battery detached for about 30 mins, no dice.

There is a black wire coming straight off my battery terminal, with a 20a fuse in the wire, can't find anything about it in the manual. That fuse was blown, replaced it and it blew again immediately. Any idea what this is for?

https://imgur.com/83dmGNR


https://imgur.com/qmJhJ7e

 

Unhook that aftermarket black wire with the fuse from the battery and see if it will crank and run. If yes then figure out what the black wire goes too.

 

As you possibly know, it ain't factory and if it's an amp someone installed, I would think it should at least be 30 amp. Since it's blown, no need to remove it since it can't induce voltage away from battery. Gonna be hard for anyone on world wide web to know where that goes. Gonna have to put your Sherlock Holmes hat on and go digging !

 

Well, no closer to an answer. Tried discharging the system and letting it sit with the battery disconnected for a while again, no change. Tried replacing that fuse again, same result. Then the battery died, went to jump it from my car and it wouldn't crank. Gave up after a couple minutes. The mystery wire attaches to a coupler and then quickly disappears into the wiring harness, right next to the battery behind the left headlight, tracing it is going to be a nightmare. Does this coupler exist on anyone else's truck?

https://imgur.com/tn6nXth

 

This is gonna be interesting. You didn't say if the unit you replaced was the stock unit. It looks like the prior owner needed to get 20 amps from the battery, even when engine was not running. So what on your truck needs 20 amps? For reference, at 110v alternating current you get about 2 amps. Any external ports/plugs for extra lighting, camping equipment, plug in coolers anywhere on you truck? Electric brake booster for a trailer with electric brakes? This also equates to 220 watts which is a popular size for a subwoofer.

How about a front winch?

It also looks like it could be a redneck anti theft device. Pull the fuse when you park to kill power to the fuel pump. Maybe.

How long have you been operating the truck with this fuse installed? Do you know if the fuse was blown or not prior to the head unit swap?

 

We're thinking some of the same things. The unit I replaced was the factory unit, and I saw no evidence of previous aftermarket installation. The truck appears bone stock, with the exception of an aftermarket tow hitch and 5 pin trailer hookup. If anything is there it's been well tucked away. I've had it for a whole week, had no problems before. I did have one instance where the truck fired and died, just had to crank it again and it was fine. Wondering if maybe the battery is on it's last legs? It doesn't look that old though.

 

When you did this install did you disconnect the battery? If so, start the truck and hold it at 1500 rpm for about a minute. See if it stays alive, if so it's just your ECU resetting.

My truck has done this before when disconnecting the battery for long enough. It would start but it didnt "know" how to retain idle, so if I drove and came to a stop it would die. If I let it idle in the driveway it would die.

 

Yes I did, will give that a try.

 

Do you have aftermarket fog lights or HID headlights? Where that line runs I would guess that's the case. My HID have a 25 amp fuse with a similar arrangement.

 

Darkness, you're a hero. I can't believe after 6 hours the answer was to give it some gas. It's still wanting to idle real low, under 500, but its running. Will the ECU get it back together on it's own?

 

Geezus I had the same thing happen to me when installing SwitchPro. I couldn't figure out why my truck started up and immediately died, especially since I didn't wire the Switch Pros up. Just installed it and pulled the battery while doing it. Makes sense.

 

Wow. Crazy coincidence. I had my battery unplugged for a few hrs today (2018 sr5) while working behind the stereo on a FRAC harness and mine died on startup as well. Freaked me the F out!
“Great... what trouble did I get myself into now!?!?”

Wish I read this earlier!

 

Yeah, drive it around the block if you can and if it dies at a stop just start it again. It takes a mile or two for it to learn idle control. Maybe wait for daytime.

I'm pretty sure that wire is from some sort of lighting.

 

Is that "Divided Sky" like the bar in Meyers?

 

Either way if it keeps blowing, whatever it is. DC that thing. Sumpin aint right.

 

Nope
As in this.....
https://youtu.be/avUeS5SZHTU

 

OH ha! As soon as I saw the thumbnail...Yep.

 

Dudes, thanks very much for the help. I'm very psyched about this truck and feeling like I had messed it up already after a week was not super fun. In celebration, here's some shots of the new ride. 163k on it, certainly not perfect but pretty damn clean compared to a lot of what I was seeing in my price range ($6500).

https://imgur.com/ZXHBHmS
https://imgur.com/W2YZsdw

 

Guys, you missed an important point above. The wire runs into a wire harness. That would indicate that, whatever it is, it came from the factory like that. Running a wire for an amp, you would run beside the harness. It would be impossible to run the wire IN the harness.

 

I was thinking the same thing, it would take a real dedicated modder to unwrap the loom to incorporate one new wire. Either way, I think that blown fuse was probably a pre-existing condition to today's events. Would still love to know what it's supposed to be doing.

 

Its definitely not an amp. I highly doubt it is factory either, unless it's a wacky fix for fog lights. There is no factory wire running off the battery with an inline fuse. I'm betting there is or was lights running off that.

 

Does it actually run into the harness? Looks like our could go behind the harness and come out on the other side then run down into that hole.

 

What happens when you remove that fuse from the small black wire and just leave it out? Will the truck run? Does it still idle low? If it keeps blowing the fuse when you replace it, stop replacing it and just leave it out until you find the other end of the wire, as something is not right causing that fuse to pop each time its replaced.

 

I do not know what that connector is, I do know that on my truck that connector has a blank factory plug (no wire) stuck in it. This would seem to mean its some kind of factory option not used on my truck....which someone wired up on yours.

If its the plug I think it is. (red circle)

Other possibilities in that area, are the day time running lights, mine are disabled but normally the two connectors (green circle) are plugged together.

The bottom left daytime running light connector is mounted to the inner fender with a plastic rivet, the mystery red circled wire, was just taped down to the harness, I fished it out for the pic.

Front of the truck is top, battery to the right, fender to the left.

 

The grey connector is factory, but the wire and fuse running directly from the battery are definately not factory.

 

I just checked my 2000 SR5. I have both sides of that connector (red), and both ends run immediately into the factory harness. So difficult to say what it's for without doing more digging. And I have to get ready for work.

 

Well, that is interesting. I only have one side, coming right out of the wiring harness and factory capped with just a blank sealed plug with no wire.

So does that mean your mystery connector is one of the day time running light plugs? Or do you have your DTRL plugs, both sides of the red circled plug AND yet another plug that is connected to the battery?