2G No Power Windows, Dashboard, Defogger, but everything else seems okay...

[GHSTII]

Hey folks,

Figured I might as well make a thread about this. I've been combing through the forums and the Electrical Factory Service Manual to assess an issue I'm having. I'm posting it here in case anyone has any productive input they'd like to share, or in case it may become useful in the future.

While driving the other day, my dashboard died. Fuel gauge remained constant, but all other gauges powered down. Dash lights still work. Car stayed on. Wideband remained active. I was able to get home safe and sound.

I realized the power windows weren't working. The defogger wouldn't work. However, I was reviewing the log I recorded in ECMLink v3. No fault codes, and I realized that I could still read the speed and RPMs. Like I said before, the wideband remained functional. So I resolved that the ECU is fine.

I could hear the fuel pump prime when I turn the key. The radio remained active. My wideband is spliced into what was formerly my cigarette lighter, which I now have split off to a rocker switch that I can conveniently use to check for power. I used my test light to check the main fuse, which showed positive. I checked other relevant fuses and relays, both inside and outside the car. All of them were good, so I moved to the grounds and harnesses. Nothing stood out.

I did my best to not accidentally cause a new problem, considering the vehicle is still mechanically sound. I just found the combination of failures was kind of strange, like the car is kind of "confused." Of course, the defogger and dashboard are within close proximity of one another, but the hazards and A/C work fine, as do the electronic door locks.

As of now, I think the most likely culprit is the ETACS-ECU. I've begun searching for one, but like I said, I figure it couldn't hurt to post here as well in case there's something else I should be considering.

Thanks!

 

[chrysler kid]

As a base line I would check the connection on the back of the gauge cluster to make sure its fully seated in the connector. Make sure the 4 screws that hold the cluster to the dash are tight and intact, that you didnt just hit a bump and the cluster popped slightly out of contact with the harness

 

[GHSTII]

Alright, I'll check that out. Noticed there are no lights or sounds when I turn the key except for the wideband. Maybe there was some sort of surge that killed a few accessories independently.

 

[chrysler kid]

Do you have a turbo timer installed? The other possible culprit is the accessory 1 and 2 power wires under the steering column from the ignition switch. Your typically have to tap these wires for the turbo timer to work after you remove the key to keep the car running. And it sounds like your problem is similar to what i would see when a car was counting down to turn off with a turbo timer

Or is that what you were referring to with an etsac-ecu? Ive never heard of that term, but ive only had to rewire the interior harnesses on 2g fwd cars

 

[GHSTII]

I don't believe I have a turbo timer, but I'm glad you mention that because it gives me a really good idea of where to look. Going to take a look within the next couple of days, and I'll update if I come up with anything to show for it.

 

[chrysler kid]

Yeah, thats where I would start. There are 2 wire power wires under the column that go to the ignition switch. All of the main accessories run from the triggered feed on the switch. My guess would be some one tapped one of those wires and now they are having trouble

 

[GHSTII]

Update:
Checked all the connectors along the accessory harness. No dice.
Meanwhile, I’ve driven the car a bit. I’ve noticed a couple things.
The fuel gauge dwindled to zero, but didn’t rise at all since I last filled up.
As of yesterday, ECMLink stopped responding on both my tablet and laptop. However, my regular scan tool works perfectly fine.
Biggest thing of note was today while driving, I got on it a bit and saw the boost and oil gauges reset, then they went right back to reading, but in the default color.
I was able to replicate that.
I started to lean into the prospect that my actual ECU is fried, but everything still works perfectly fine, including the wideband and cigarette lighter.
I also realized that I opted to install the gauges with extended fuses at the kick panel. I take this as another sign pointing to that particular harness being “confused.”
A nice fellow on here reached out, so hopefully I can get an ETACS unit off him and see if it resolves the issues.

 

[GHSTII]

Replaced the ETACS ECU. No luck

OBDII is still getting power, but is unresponsive to the regular scan tool now as well. The gauge lights flicker. Still runs and drives fine. But then I went to turn on the AC, and the horn started blaring non-stop

Going to go back over the connectors again. I guess I’ll see if I can send in my ECU for repair? That’s all I can think of at the moment.

 

[GHSTII]

Update:

Not quite sure what was up with my tools before, but I was able to track down blown fuses at the interior junction box. Got back the gauges, then the power windows. Got my accessories back. Felt like a huge win.

It seems my data link port may be a separate issue. Not sure if it went out at the same time the fuel pump stopped priming, but for now I’m moving forward with the presumption that those two symptoms are related.

The backlight of the basic scan tool is dim, but the port is getting power and it can connect. When I tell it to read codes the backlight flashes, and the device prompts me to check the ignition and connection.

Will update whenever I figure that out.

 

[GHSTII]

Spent a while hunting for the short circuit, but came up "short"

Decided to take a break and start it up to see what would happen. Fuel pump still not priming, but after a couple attempts it came on. Everything looked good. Then I clicked the power windows and it killed that, the door locks, the AC, and defogger, etc. It was the end of a long day, so I haven't gotten to test what else may have gone out. Still drove it around a bit, and it did fine. No new issues.

Luckily, the gauges are still working. That might be the only thing though. I reset and tightened the wires at the positive battery terminal per someone's advisement, as well as the ground wires.

Forgot to mention I pulled the horn fuse after the previous drive, because it wouldn't stop blaring. Did some testing, and realized I could put the fuse back in and remove the relay to get it to stop. I also bypassed the ignition switch because I spent days fighting a jam at the key cylinder. I know it's controversial, but I opted to install a "push start," as well as a kill-switch. It knocked out multiple birds with one stone, and I was able to solder and secure those wires with confidence.

Been looking at these diagrams over and over, and I'm still not quite certain what I'm looking for. I've pulled just about every fuse and relay in the engine box, junction box, under the dash, and in the center console. I guess it's shaping up to be a deep wiring issue, especially considering how much I've cleaned up along the way.

I'll update again if anything of note comes up.

 

[Jap slap]

Have the same problem, but mine escalated to blowing the ignition switch fuse eventually, and instrument cluster fuse is short to ground as well. Did you ever find the fix for this issue? Thanks

 

[GHSTII]

Actually, it was the final straw with the wiring that prompted me to just pull the whole control harness and go standalone ECU
That way if anything like it happens again, all the major functions are isolated from everything else.

That said, I have since replaced the alternator fuse, and that helped with a seemingly related issue I was having in case you may want to try that.

 

[luv2rallye]

All your symptoms sound more like a grounding issue (ground somewhere not making good contact).

 

[Jap slap]

Thanks, mine is a starter signal wire short to ground, but the blue wire from the ignition switch to the etacs is also short to ground but only when plugged into the etacs. If I disconnect the top connector to the etacs, I can leave the ignition switch harness plugged into the etacs and no longer short to ground. Also stops blowing the instrument cluster fuse. I have a standalone ECU but it doesn't help if the ignition switch fuse blows, because it shuts down all things that aren't constant power

 

[GHSTII]

Ah, you’ve got a point there. Did it randomly happen, or did you change anything recently that may be related to the issue?

As Gary mentioned, you may be looking for a loose connection or broken/frayed ground wire.

 

[chrysler kid]

the main junction for the ignition harness is under the seering column. there are larger white wires running from the column under the dash to the rest of the vehicle

it is most common that this main ignition accessory harness is cut up from a turbo timer install or vehcile alarm installation

remove the lower dash panel under the drivers side below the steering wheel and look up and visually inspect this harness area for evidence of aftermarket wiring

there is a factory service manual online for free at Www.charm.li

it sounds like problems from shorting in these main accessory ignition power wires under the steering wheel in the dash

 

[Jap slap]

Thanks for the link to the manual! I'm a bit beyond removing the knee bolster, I have the entire dash, console and hvac out of the car , there is something tapped into the blue wire from the ignition switch to the etacs but it has been removed.... wiring and fuse holder were still there so I repurposed it for my wideband. Have since removed it though.... I've been a mechanic for 27 years and the last 8 or 10 I've been a journeyman GM dealership tech so I did everything correctly. Backstory.... I got the car in boxes and bags and had to assemble it from the ground up. This problem started with it randomly blowing the instrument cluster fuse, no common symptoms at that time, just every once in a while the fuse blew. Then it would blow it before I got out of the driveway, and now it blows instantly at key on. Then power windows quit working but the fuse is good, driver's side door lock doesn't respond to the button. Then it blew the ignition switch fuse and it is short to ground. Grounds are definitely grounding

 

[Jap slap]

Found my problem for anyone who experiences this in the future.

You must be logged in to view this image or video.