Relay and Switch Question

[P1K5Dave]

Asking here because the guys over at TundraTalk aren't helping, and I know we've got some good electrical guys here.

The short question is: What do you make of a relay that clicks on and off while the switch it's connected to stays in the same position?

My 2014 Tundra has been signaling that my driver door is open as I drive down the road. So I replaced the door jamb switch, and it didn't fix it.

I was able to drill a little deeper by sitting in the parking lot with the door open, engine off, key in the accessory position. I could then push and release the jamb switch, and it would show the door opening and closing. Good...

But then I held the switch in the door closed position, and after a few moments it started freaking out and showing door open/door closed intermittently. I could hear a relay in the dash clicking on and off, even though the switch was held in one position.

My first thought is a short in the line between the switch and the relay, but I wanted to know if a faulty relay could act like this (?)

 

[Remington]

If its a contactor relay, either the contacts are worn/dirty/burnt or the resistor if equipped or magnet inside the relay is is bad. Unfortunately, automotive relays are plastic and sealed so ur looking at replacement.

 

[CID]

If it's a normal automotive relay, I'd replace it first, they're cheap and plug in, no soldering or heat shrink etc.

 

[Buggyman]

had similar problem on a ford platinum and it was what looked like a fiberglass rod in the boot between the door and the body to keep the boot from folding. the end of the rod rubbed all the insulation off of about 4 wires and caused a random short

 

[P1K5Dave]

OK, I'll shotgun replace that sucker and see what happens. Now, how the hell do I found out what relay it is...

 

[Smitty335]

OK, I'll shotgun replace that sucker and see what happens. Now, how the hell do I found out what relay it is...

Open the door?

 

[P1K5Dave]

What door, you mean the fuse box? I think there are a few of them on this truck. I haven't had it more than 3 yrs and I think I've only been in one of the fuse boxes once. Seems like there's relays in there, though...

As an added bonus, I get greeted to a full-blown car alarm every few days because it's sitting there locked and suddenly thinks the door is open. The last few nights I just left it unlocked to skip it.

 

[Neohio]

Probably controlled via canbus. Might be getting dirty information over the system.
Do you have access to a scanner with live data on the bcm?

 

[P1K5Dave]

Tomorrow I'm going to check that plug and its contacts on the back of the door jamb switch. Seems more likely to me, especially the way that relay was behaving.

I do have the interface to hook my truck up to my laptop. Used it to change settings the dealer won't do, and to program keys. But anything beyond that stuff may be out of my range...

The clicking relay isn't in the box, somewhere behind the kick plate.

 

[Remington]

OK, I'll shotgun replace that sucker and see what happens. Now, how the hell do I found out what relay it is...

Get a shop manual and a wiring diagram or download one.