Help Please - Fighting new Gremlins

[tj43]

Thanks everyone. Yall were correct: it was a ground issue. I managed to fix that problem. It was the one loose ground wire at the ground bus (photographed above).

Interestingly, the retrosound radio is still dead (and is truly dead—I tested it on the bench). So, I think the radio really did randomly die a day or so after I installed the aux lights—just a crazy coincidence. I am trying to come up with some way that I could have killed it while installing the aux lights and I really don’t see how the two things could be related.

I did most likely cause the crazy ground issues. In my rooting around to try to diagnose the radio, I bet I pulled that ground wire loose from the ground bus, thus causing the dash lighting shenanigans.

So, I am back to where I was a couple days ago: everything in the truck (minus the radio) is great. I guess I need to call retrosound and have them tell me that I am SOL on a warranty replacement.

At least I went ahead and replaced all the lights in the cluster and the bulb in the HVAC head, which has been out as long as I have owned the truck (I didn’t even know it lit up until I was searching for bulb types for the cluster ). I’m also going to replace the dash speakers while the dash is off and give everything a good cleaning.

 

[EvilGenius]

Glad you figured it out. It's always grounds lol.

 

[supertrucker]

My historically very-reliable Suburban threw me an electronic curveball today (and it may be my fault). I will endeavor to provide the full story, since I do not know what may or may not be important:

I installed some back up lights yesterday afternoon. It was pretty straightforward. The lights wire to a relay that I installed on the firewall. The relay gets its main power from the battery and grounds to the radiator support ground near the battery. The interior switch controlling the relay grabs switched power from an add-a-fuse tap on the main fuse panel in driver's footwell (cant remember which one--maybe the auxillary heat/AC?) and grounds back to the relay. So, the entire system only interface with the Suburban in 3 spots: (1) positive battery terminal, (2) ground bolt at the rad support, and (3) the add-a-fuse. The install was straightforward and uneventful.

However, after the install my radio (Retrosound) that has been working flawlessly for a year or so would not power up. The Retrosound is a little unique because it requires 3 items for power: (1) a ground which it gets from the radio harness, (2) switched power (also from the radio harness), AND (3) constant power. My retrosound gets constant power from another add-a-fuse on the horn circuit in the main panel. I assumed I had just bumped that when doing the back-up lights since it was the only thing in the vicinty of where I was working. I monkeyed with it, swapped a fuse and it worked again . . . for a while.

Fast forward to today and the radio stops working again. I hunt around under the dash for the better part of two hours trying to figure out the issue. Eventually, I assume the radio has simply died and I remove it entirely. My plan is to attempt to power it up on the bench later and, if that fails, call Retrosound next week to discuss warranty repair or replacement. I then go to drive the Suburban back to my shop tonight. I turn on the headlights and the following occurs: (1) brights are on when in the non-bright setting (they turn off in the "bright" setting), (2) both blinker indicators are constant on (unless I move the stalk in which case they blink with the indicators), (3) no instrument cluster lights at all, and (4) the gas gauge falls to empty. If I turn the headlights to "off" everything reverts to normal.

So, what on earth did I do? I double checked the ground at the rad support (since it was the only ground I messed with). It seems fine. I removed a couple of my add-a-fuses thinking maybe they were a problem, but that did nothing. What am I missing?

A couple random thoughts in my head: I wonder if the radio is fin and its loss of power is a symptoms of the same problem--I just didnt notice the larger issue yesterday or earlier to today since it was daylight and I had not used the headlights. Conversely, is it possible the radio is actually dead and simply having the radio disconnected (radio harness is dangling but not contacting anything) is causing all this other drama?
I need some direction and thoughts on where to troubleshoot from the GMSB braintrust. Thanks in advance.

I think evil genus is right. Check all grounds front to back. You may have knocked one loose. Make sure there is no paint under the connectors

 

[Raoul Ross]

In that picture, what's that wire hanging right in front of that round hole? Is that a broken connector or is it connected to something not shown in that pic?

EDIT: Missed that you fig'rd it out. Good Job!

 

[Oldbear42]

To me it sounds like a ground problem. As grounds degrade their current carrying capacity goes down. By adding your new rear light circuit you exceeded your current capacity for your grounds. Since then you're just playing whack-a-mole with what circuit has a good enough ground path to function.

My truck doesn't have stock grounds anymore so I'm not sure exactly how the factory grounds are, but I think the only ground connection to the battery is near the alternator bracket. If that's true that means all grounds for the whole truck go through the engine block. If the path between your new ground and that is rusty or just poor you're going to be having a bad time.

So to check your grounds go backwards from the battery. All ground connections have to return to the battery to complete the circuit. So clean the connection closest to the battery. Then go to the next connection in the chain from there. And so on. If that doesn't end up fixing things at least you'll have less problems in the future. Bad ground are probably something like 80% of all electrical problems.

Many electrical gremlins are sent away by installing a few extra ground connections - I learnt this on my '82 Suzuki GS1100GK and have been following the technic for years now. I added a few extra body-to-frame grounds on my square (and replaced some dodgy stock ones).

 

[Oldbear42]

Did you use any one-way diodes? My Yukon backup lights are turned on by a dash switch and by my reverse lights (controlled by a relay and powered from an accessory block). I have a one-way diode on the reverse light "signal" wire to the relay as a precaution to avoid any backfeed.