GM 2019/2020's and connection

[wbrisett]

I recently upgraded my tow vehicle to a 2020 Chevy 2500HD and on our first trip with our Airstream I noticed a warning in the new trailering section of the DIC that our electric brakes were not connected. I pushed the AS seven blade cable in further and couldn't get anywhere with it.

Upon searching various forums there seems to be quite a bit of talk about this with various trailers. I stopped by Northern Tools and picked up a tester and new wiring pigtail. I immediately noticed how the tester fit snuggly into the 7 blade receptacle. The tester didn't work as I expected but it seems GM is using some smart technology and it wasn't lighting up the LEDs as it should.

I put the AS cable back into the truck receptacle and noticed a huge difference in how sloppy it felt and in fact it came up on the truck as disconnected. I pushed it in further and it read as 'connected' properly (although the electric brake issue didn't go away).

I decided to replace the whole pigtail but as I started tracing the wires they go into the frame and then ??? I can see where a couple go into the rats nest of power in the AS flying cloud 27FB storage area. I tried to sort out what was what, but that seemed pretty hopeless.

So two questions really.

1. Has anybody who has a 2019 or 2020 GM (chevy or GMC) noticed how poorly the AS connector fits? If so, have you had issues with connections? (specifically the electrical brake connection)?
2. Has anybody replaced the entire pigtail? If so, is there a central point where they are all connected?

[Adventure.AS]

Did your seven-pin connector fit into the receptacle in your old tow vehicle without an issue?

[KK4YZ]

Don’t know if this is helpful but a guy on our caravan last summer had a problem with trailer connectivity with his GMC 2500. He would constantly get ‘trailer disconnected “ message and chime, followed by “trailer connected” message and chime as he went down the road. Drove him nuts. Had it in to more than one RV shop and GMC dealer. Nobody could find the source of the issue. He eventually traded for a new GMC 3500 which solved the problem for a while. I think he just wanted a new truck.😄

Hopefully yours is more straightforward like a bad connection. If the 7 pin connector seems sloppy, you might want to try conductive grease in the pins. You might also try to shim the plug/receptacle with something to make it mechanically tight.

Good luck with that.

Jim

[GCinSC2]

Care to try simple first? You stated the tester felt tighter than your 7 way?

Replace the 7 way plug only as a start. Disconnect batteries and if your handy a DIY type not a bad project at all but pretty important which new plug you use. Look at your existing plug got the split blade terminals, kinda soft springy? Find a Pollak brand that has flat blades not splits. I think you'll find its a good replacement plug. They exist with a metal housing too. Not sure on yours never seen it but on my 2007 Classic under the couch there is a black terminal box maybe 3X5 ish and the cable goes in there. I'm running a metal Pollak on mine for several years now, plug it in, mini bungee and we're on the road.

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Gary

[SYC2Vette]

I have had the same problem with my 2018 GMC Canyon and 2017 20' Flying Cloud/Bambi. Worst effect was that after a long steep descent in Colorado mountains I overheated and seriously faded the Canyon's brakes since I had no trailer brakes working at the time. I cleaned the trailer side terminals, applied some dielectric grease, and then pinched all the contact tabs together, still does not "feel" like the greatest connection. No problems after that but when I figure out who makes the best connectors will be replacing both.

[wbrisett]

Originally Posted by GCinSC2

Care to try simple first? You stated the tester felt tighter than your 7 way?

Replace the 7 way plug only as a start. Disconnect batteries and if your handy a DIY type not a bad project at all but pretty important which new plug you use. Look at your existing plug got the split blade terminals, kinda soft springy? Find a Pollak brand that has flat blades not splits.

I have a Pollak ordered, GM is recommending those. In fact, somebody on one of the GM forums claims the Pollak is one of the few that comes closest to meeting the specs of the SAE J560 standard (he claims in he tested a bunch of different ones in his former job).

So, we'll see what happens when I replace it.

For the record, I did clean the contacts with contact cleaner and then applied dielectric grease, but the problem really seems to be the plug AS is using.

[GCinSC2]

That sounds good. I carry spares in my toolbox for the other guy. Mines doing just fine.

[Deeno]

I had a similar issue last year; repeating "Trailer not connected" message. As it turned out, it was not the truck, it was the trailer. A mobile technician crawled under the trailer and found a frayed and severed brake wire on the right front wheel. The other three wheels had protective tubing on the wires, but this one did not. He spliced the wires and secured them. Apparently, for the first two years, the torsion arm would occasionally rub the wires, and eventually this wheel disconnected.
NOTE: the four brakes are wired in series. This means when one wire breaks, all brakes are unpowered. I'd suggest Airstream wire the two axles in parallel, so if one wheel disconnects, the two on the other axle would still function. Half of the brakes is better than none of the brakes.
Suggest you inspect your brake wires at the wheel.

[Gene]

I had the brake wires on our Airstream disconnect themselves to one brake. The connectors had not been installed correctly, so I did it right and it never was a problem again. The connectors used in 2007 simply slid together and then were supposed to be pressed tight with a wrench. They had not been, so I did it and then wrapped the connector in electric tape as a back up (the tape will eventually loosen, but is easy to replace).

But in the circuitry from the truck brake pedal to the trailer brakes, there are many places were there could be a bad connection or a broken wire. If a visual examination does not show any problems and any connections you can access are tight and clean, then jumping around various wiring to see if there are breaks in the wiring you can't see would be the next step. But if you know how to use a continuity tester for finding broken or disconnected wires, that is the best way to do it (electrical testers are sold at stores like Lowes and Home depot as well as neighborhood hardware stores—some test for continuity). Although auto and trailer wiring can be difficult to understand, any shop should have at least one person who knows how to trace problems like this.

It does seem from previous posts there may be a problem with Airstream plugs not quite fitting GM receptacles. I am surprised these items are not standard. The round lugs (male part) that fits into the receptacle can be slightly flattened (more like a slight oval) with a wrench like a channel locks, just enough to fit better. That is very simple so long as you don't flatten too much and can be consistent with all the lugs. Fir a loose plug, that would be my first step.

[rmkrum]

Trailer brakes are supposed to be wired in parallel, do the loss of one brake wire will NOT kill all the brakes. If there is one example wired in series, the braking effort will be greatly reduced and it needs fixing.

[Atwebs]

We struggled with a 2019 GT and a 2016 Chevy truck -it said "attached" then "unattached" every couple of minutes with the horrible ding-ding-ding-ding warning sounds the entire drive. All said, even though the dings were driving us crazy -the electric brakes worked just fine.

Both Chevy and Airstream worked with us very hard to eliminate the issue. We tested both the Airstream on other tow vehicles (no issue) snd the truck on other trailers (no issue). Airstream and Chevy even send each other all their service bulletins to figure out what was going on. Best guesss was they just didn't get along, never did figure out why.

Airstream added some sort of connector that lessened the "dings" to once every 15 minutes or so -still enough to make us crazy though.

Never did get to the bottom of the problem though...eventually we got a 2019 truck that did get along with the trailer.

[wbrisett]

Tomorrow after church, I'll crawl under it and see if I can locate any problems with the brake wires. But I do think it's more than that because the plug is so difficult to stay in the truck connector. But from searching around, it seems that GM and Airstream point fingers at each other. Next week, I'll replace the Airstream plug with the recommended Pollak brand connector and see if that helps. The replacement pigtail I bought from Northern Tools, fits tightly, and since I took off on Friday, thought I would replace the entire pigtail, but as I said earlier, I had issues trying to trace the wires back once they went into the frame. Oh well... I'll just wait until the plug arrives and swap it out and see if I make any headway.

[mefly2]

Check for oxidation - even on a new rig. We had to clean both the blades and socket terminals / receptacles with an emery board and then PUSH hard to secure the plug all the way into the vehicle. The spring loaded cover will often prevent full insertion. This has been our experience on a 2017 Yukon, 2019 Colorado, and 2019 Silverado.

[wulfraat]

Pollak male interface/receptical on my 2017 gmc 2500 (same part installed on the 2018/2019 2500/3500 btw) has worked without issue since new with my 2017 Airstream equipped with LED lights.

Perhaps they changed parts / electronics on the 2020 which is a different gm platform...

[Ridgerunner3]

My 2015 Chevy 2500HD had the same problem. I first went through all of the trailer wiring and replaced the trailer umbilical cord. The problem still existed. I then started checking and cleaning the truck connector. The solution ended up being to replace the truck outlet connector with a new Pollack connector. All is good now. The link bellow is the part I ordered from Amazon. The package says "Hopkins", the part is a "Pollack" and is identical to the failed part I removed from my truck. I dropped the spare tire down to make access to the back of the plug for removal easier.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[wbrisett]

A bit of an update... I checked everything on the Airstream side, physically checking the wiring, measuring the resistance from ground to the brakes from the connector and that was within what various sites say it should have been. Since I was by myself, I couldn't do the one thing I really wanted to do which was measure any voltage from the truck connected to the brakes. I didn't have a 12 volt battery with me, nor did I have any connectors to hook a 12v battery directly to the brakes. But now, I'm thinking it must be the truck!

I was hoping to stumble across somebody at our storage facility who was working on, or putting away their rig, but unfortunately there was nobody around. I decided that since all I wanted to do was test the truck wiring, I would borrow my neighbor's Coleman. I pulled up next to it and guess what? Same exact error. So, I'll head up to the dealer and see what they have to say about this... I'll tell you though, I'm really getting pretty irked with this truck. 8 weeks in the shop already and all for electronic type failures. I love the new tech on these things, but don't let anything go wrong!

[Adventure.AS]

Originally Posted by wbrisett

... I didn't have a 12 volt battery with me, nor did I have any connectors to hook a 12v battery directly to the brakes. But now, I'm thinking it must be the truck!

...

Your trailer has a pair of 12 volt batteries. If you momentarily pull the break away switch on the trailer tongue you would be able to hear the trailer brake magnets activate. (Be sure and plug the switch back in or it can damage your brakes and drain the batteries.)

[crispyboy]

Originally Posted by Adventure.AS

Your trailer has a pair of 12 volt batteries. If you momentarily pull the break away switch on the trailer tongue you would be able to hear the trailer brake magnets activate. (Be sure and plug the switch back in or it can damage your brakes and drain the batteries.)

You can also check each wheel with a compass. Bring the compass close to each hub and the arrow will swing toward or away from the brake magnet if it is working.


I think your correct that it is likely the connector on the truck that is faulty. I agree that the automotive electrical systems have needlessly gotten much too complicated to the point that electrical gremlins can make a modern car shut down and become useless. Rolling computers.

[no_worries]

[*]Has anybody who has a 2019 or 2020 GM (chevy or GMC) noticed how poorly the AS connector fits? If so, have you had issues with connections? (specifically the electrical brake connection)?
[*]Has anybody replaced the entire pigtail? If so, is there a central point where they are all connected?
[/LIST][/QUOTE]



I have a 2020 GMC HD Denali. I receive an error message when connecting the trailer that states electric brakes not detected. There’s also a light error. In addition, if I leave the umbilical card plugged in with engine shut off, there is a continuous slow flash on some of the trailer lights.

Interested to see how your visit to the dealer goes...

[wbrisett]

Originally Posted by no_worries

I have a 2020 GMC HD Denali. I receive an error message when connecting the trailer that states electric brakes not detected.<snip>

Interested to see how your visit to the dealer goes...

So, have you talked to your dealer about this yet? I'm taking mine in today. So far this truck has spent 8 weeks in the shop! They (dealer and GM technical support) tracked down the error that was causing the truck to throw up an engine fault (only after replacing 3 modules, including the ECM, none of which were in the parts system yet and had to be ordered individually from the assembly line in Michigan). I absolutely love the HUD in this truck, and from a mechanical standpoint, it's solid, but the electronics thus far has been the bane of my existence and its spent more time at the dealership than on the road, which is about to make me take a bath on the unit and buy something else.