Hello all, first time posting and man if it isn't a doozy.

I bought my girlfriend a new head unit for her 98 4Runner. Being the handy capable boyfriend that I am I went to work installing it.

I unplugged the negative battery terminal and, after removing the stock amplifier, matched up the individual colored wires with their counterparts in the wiring harness adapter I had pick up for this project.

The stereo works great, much better sound and way more features; the only thing is now the vehicle doesn't start.

If the battery is plugged in and the key is in the ACCE or ON position the car displays the check engine, battery, and open door warnings. The stereo and all of the electronic work as expected but there is the annoying ticking of the open door warning even when the doors are closed. When I turn the ignition I can hear something happening in the engine bay (sounds like electric switches being flipped) but I can not hear the starter cranking.

The issue persists even when the new stereo is no longer connected to the vehicle.

I was able to get the vehicle running twice after having reseated the negative battery terminal and when it started it worked as expected but it wouldn't start consistently.

I've already checked all of the fuses both in the engine bay and under the steering wheel.

Does anyone have any suggestions on how to go about getting my girls car to start reliably again?

Do you have an alarm on it? Sometimes removing the tock head can cause the alarm to not let the vehicle to start, try finding the button for the system and press it when you are about to start the truck.

Check and clean the battery terminals. Sounds like a loose or corroded connection

Sounds like a bad battery terminal. Try cleaning, If not cleanable, then replace the terminals.

Dumb question but does the battery have a good charge? You can drain a battery pretty fast if your playing with the radio and the and the vehicle is not running

Thanks for all of the suggestions everyone. It seems that the most suggested is that the battery terminals may be the culprit.

I used a terminal cleaner and the connection is both clean and tight. I also confirmed with the girlfriend that the battery itself is less than a year old so should be fine. I don't believe the battery is drained too much to turn over the engine. I'm able to have the cabin lights on and turn the ignition and it doesn't dim the lights at all.



Here's the alarm I was able to find as that was also a suggestion. It doesn't seem to have a reset switch that I can hit while cranking the ignition. I'll check the manual for it later.

I'm going to take a break from it for a little. Any other suggestions would be super helpful.

There aren't any wires in or around the radio wire harness that might be causing this?

This may be a bit of a long shot and completely unrelated but I had my battery die on me one day. It was old so I bought a new one and installed it. Went to turn it over and it would not crank. All interior lights and everything came on. I ended up putting the jumper cables on it and it started right up and has been fine ever since. Just an easy suggestion you could try.

Sounds like a dead battery as the above dudes said, just hook the jumpers up and see if anything changes.

If you have a volt meter, check the battery's voltage reading first.

This is not the most accurate way but if done properly, yes. Put the volt meter on the battery, check to make sure you have at least 12.6v then crank the engine for 15 seconds and make sure the volts do not drop below 9.6 at any time. If it does drop below 9.6V, you need a new battery.

Also, a voltmeter will only show you voltage thats in the battery.
You need a battery tester that can test to see if a battery holds under a load (load test)

that alarm isn't stock, i hate aftermarket alarms for stuff like this.

As others have said, check the cable connections. The negative cable as per the picture is not stock so that could be the root of your problem.

Do a cursory check though of the battery.

No, none of the radio wires would cause it not to start. They could however kill your battery. Since the alarm appears to be an Audiovox, here is my suggestion. I hate aftermarket alarms because most people don't know how to defeat them, unless they are car thieves. Try disconnecting your battery and then turn the ignition to the on position, reconnect the battery. Sounds dumb I know, but over the years cars would come to me with no remote, and when we disconnected the battery the alarm would set itself.
As for reset switches, they usually get mounted near the drivers feet or knees.

Worth a try, but be sure to make sure the battery is charged and the terminals are clean. Over the years I have done a lot of battery troubleshooting with just a voltmeter, of course if you have a load tester that would be nice too.