Door lock/horn issue

Hi everyone! So I've got an issue with my door locks not working. I have a 2013 tundra crew cab with 184,000 miles. I bought it used in 2019 and am the 2nd owner. It started off occasionally not locking with my remote so changed batteries and still same issue. Then just stopped all together. Along with that my horn stopped working at same time but can still set off security alarm. 3 of my 4 doors won't lock with remote or from in the truck. For a while my rear passenger door still locked with remote and switch in the truck so I though bad door lock actuator motors. I put off changing them as it hasn't been a need. Now suddenly the rear driver side door locks with the remote and switch but the other 3 won't lock. All fuses have been checked. Relay was swapped out with a new one. I am getting power to each door. Any ideas on what to look at next? Also, maybe important or maybe not my truck has an aftermarket remote start that was put on by previous owner. I have never been able to get it to work with the remotes provided for it, however some garage door openers and other remote starts will start my truck. I'm a contractor and while on a job site one day discovered every time I opened my customers garage door my truck would start. I'm not sure if that has anything to do with locking issue or not. I can say that the locks worked fine for the first year I owned it and at the time my neighbor had a toyota camry with remote start and everything he started his car he started my truck too. But locks still worked then. I think I've given all the info but if more is needed please let me know. Thank you in advance for any advice or ideas!

 

Ouch. Wish I could provide some insight. That sounds frustrating. I would have had the remote start kit removed after experiencing the issues you have.

 

I thought about removing it several times but was told by a few places they could reprogram it and it would stop doing that. Then they all want 400-500 bucks to do it and I didn't want to put that kinda money into something that wasn't a necessity. But I don't think that's what's causing the other issues. I really think it's something in the wiring to the door lock actuators but at this point idk where to look.

 

I just saw in a video the other day where a Toyota Tech was talking about problems he sees on these Tundras. He mentioned aftermarket remote starts causing issues. He didn't mention the problems your having but rather starting problems, however it would be worth checking. Here is the link to that video: https://youtu.be/l2OAHImTgA8?si=89kLiLRqvP_CxXPF