Silverado wiring fun

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Jun 3, 2005
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Location
Santa Barbara, CA
So the power locks stopped responding again on my truck. I had posted before about discovering it had some janky wiring in the passenger door including 2 random relays that I replaced and the locks worked again. Well they stopped working again. I opened up the door panel again and spent a few hours trying to get to the bottom of this. I took the cluster surround off as well as the lower panel around the column and found a Viper alarm. The wiring was terrible to say the least. I liked on the passenger door there was the factory wiring tied to speaker wire with both wires in the same end of a butt connector. I used a DT connector on that, using my new crimping pliers for the first time. Going to take this slow, I am looking for a factory wiring diagram to make sure everything gets connected. I will probably use DT connectors since I have an assortment. Here is some of what I found.

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I hate hack job wiring. My beetle was full of it when I got it too and I have been slowly going thru it all. And I hate aftermarket systems too like security systems. Glad you found the issue and are getting everything straightened out.
 
O, I forgot to mention it has a Pioneer radio. I took it out to see how that wiring was, and it was all twist connectors. There was a wire that fell out of the nest and now the radio won't turn on when I turn the truck on the radio stays off. On the plus side, I replaced the A/C control with a Dorman one and now I have working temperature. The factory control had no lights on the temperature slider. Now it has lights and I can actually make the AC hot and cold.
 
Looks like it. That is in the passenger door.
Those are not resistors, they are diodes. On a lot of different vehicles there are independent door trigger inputs for each door that usually are also run through the BCM and you need to diode isolate each one from the others. It looks like that was done in the door though, and if each door has its own door module for door lock and dome light trigger it makes no sense to me why there are diodes in the door.

This looks like it was a really bad installation on the alarm, I sure would hate to see the rat's nest behind the radio. Something like this would be best to cut out all of the alarm and stereo wiring hacks and try to put it all back together like factory original and hope it all still works. The relay with the hole in it may have either got hot and melted the housing or it even looks like someone ran a screw into it or otherwise drilled a hole in it?

I used to really hate seeing and having to fix hack jobs like this when I was in the car audio/alarm business. It's no wonder the door locks quit working. Good Luck to you BD, I hope you get it all sorted out.
 
This looks like it was a really bad installation on the alarm, I sure would hate to see the rat's nest behind the radio. Something like this would be best to cut out all of the alarm and stereo wiring hacks and try to put it all back together like factory original and hope it all still works. The relay with the hole in it may have either got hot and melted the housing or it even looks like someone ran a screw into it or otherwise drilled a hole in it?
Must have been burned. I put those in a month or so ago, maybe more. Only drove the truck a few times with it like that too. Before it had the same style of relay but with the tab to bolt it to something. I'm trying to isolate the aftermarket and OE wiring and will hopefully reconnect the OE wiring. I think this truck had some sort of factory keyless, I was able to program new OE remotes, but the relays on the factory relay panel were removed.
 
I hate hack job wiring. My beetle was full of it when I got it too and I have been slowly going thru it all. And I hate aftermarket systems too like security systems. Glad you found the issue and are getting everything straightened out.

Aftermarket security systems are really fun when they crap out in the middle of the night and the owner can't figure out how to stop the noise.
 
Those are not resistors, they are diodes. On a lot of different vehicles there are independent door trigger inputs for each door that usually are also run through the BCM and you need to diode isolate each one from the others. It looks like that was done in the door though, and if each door has its own door module for door lock and dome light trigger it makes no sense to me why there are diodes in the door.

This looks like it was a really bad installation on the alarm, I sure would hate to see the rat's nest behind the radio. Something like this would be best to cut out all of the alarm and stereo wiring hacks and try to put it all back together like factory original and hope it all still works. The relay with the hole in it may have either got hot and melted the housing or it even looks like someone ran a screw into it or otherwise drilled a hole in it?

I used to really hate seeing and having to fix hack jobs like this when I was in the car audio/alarm business. It's no wonder the door locks quit working. Good Luck to you BD, I hope you get it all sorted out.
You are correct, and looking closer, there are actually 4x of them! 😬
 
Sounds like the truck is a non-base model that did have OEM keyless entry. On those trucks you have to use an interface module to integrate the alarm with the door locks and door trigger inputs. This almost looks to me like the installer did not have or did not use the interface modules and tried to do his own wiring to make the door locks and door inputs work with the Viper alarm. Why in the world he would remove the factory door lock relays is beyond me.

The two relays that are together in pic #5 are aftermarket relays that are connected with aftermarket relay sockets which looks to me like they may have been wired in to the door locks in that door to try to do a 5 wire reverse polarity wire configuration instead of using the interface module, which could account for the removal of the factory door lock relays. Something sure went wrong somewhere to burn that one relay like that. Here are a couple of links that might help you put things back together:


 
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Looks like your typical Best Buy or Car Toys install. I hate.....HATE aftermarket alarms and remote starts. They have caused so many problems and I charge full rate to diagnose and remove them.
 
Spent a while today working on fixing the wiring on the truck. I figured baby steps is the best way to defeat this monster. I really liked the way they tapped into wires by cutting back insulation and wrapping the 3rd wire around the exposed wire and then covering it all in a ball of electrical tape. I used solder seals on the passenger door and my thoughts were "meh." Maybe if this was on a bench and I could have the wires not be moving all over the place they would be ok. O and my M18 heatgun worked really well for the solder seal things. I got a reducer tip on it to direct the heat right where I wanted it.

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Part of doing the passenger door involved tracing some speaker wire under the dash, to the driver's door. So that panel came off and while still not ideal, the wiring here was slightly less janky. What was interesting is the grey and tan wires that were tapped, were cut and left dangling from where they go into the switch pack. I didn't take a picture, but since I only had to repair 3 wires, I didn't want that T-tap still in there, I used a 3 pin DT connector. The speaker wires were the same as the other door with both wires shoved in the same side of a butt connector. I used a 2 pin DT there just to give myself some more practice with them.

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Now the doors lock and unlock with the remotes and switches. Windows also work. I think there is something more under the dash that is letting them work since the factory power door lock relays are not in the relay panel. There is a theft light blinking on the cluster that I need to figure out too. But the doors are both done so now it is time to tackle under the dash.
 
In case anyone missed the thread I made about the truck when I got it, this was a $1,500 lien sale that I picked up in June. It has around 281K miles on it. When I as going through the papers in the truck I found the lien sale paperwork from April 2020, so this thing has had an interesting life.
 
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