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700+SL2 07-17-2017 02:31 PM

Ground issue or BCM?
So this randomly happened.
01 LW300.
I hope that link works.
I pulled the BCM out and all looks good. I swapped in the BCM from my LS2 and the lights flashed the same. I didn't start it, just checked to see what happens.
Seems to run and drive fine. A few times after using the directionals the tach would pop on then off again.
What do you guys think. Hoping for a bad ground somewhere.

fdryer 07-17-2017 03:58 PM

Re: Ground issue or BCM?
Since bcm swapping didn't change the flickering lights, there may be one of several possibilities. A guess might be either poor grounds (battery has two main grounds - battery to chassis and engine block) and ignition switch.

Battery negative cable connections to chassis and engine block are easier to check than ignition switch.

02 LW300 07-17-2017 08:43 PM

Re: Ground issue or BCM?
I used Photobucket for years with good success. I can no longer say that as they have killed all of the photos posted there. Sad really it has destroyed several tutorials on my previous Geo Metro adventures. The mods here have modified their system so now we can post pictures here. Thank You.
The bcm controls the lighting and the dash, so if changing the bcm didn't fix your issues maybe you have a failing dash cluster.

fdryer 07-17-2017 09:49 PM

Re: Ground issue or BCM?
^ Yes, I've noticed this awhile back when searching threads and seeing broken links. Its the only reason I try to explain posting images here instead of using a host site that can break for whatever reason they feel fit. The time to resize and reformat images for posting here as thumbnails counters lost links.

700+SL2 10-03-2017 03:56 PM

Re: Ground issue or BCM?
Sorry to have dropped this and now picking it back up but life got busy and the L kindly **** itís tank straps and has been sitting since.
So today I decided to hit my head against the wall and work on the L.
Orig BCM, dash lights flicker like crazy and gauges donít work except for sporadic flashes.
Swapped in a BCM from a 00 LS2 with known broken odometer, same results.
Orig BCM and cluster from 00 LS2 and same flickering.

I ran out of time today before checking battery grounds. Iíll clean them tomorrow.
Anything else I should look at?

fdryer 10-03-2017 06:36 PM

Re: Ground issue or BCM?
Did you check for blown fuses?

I removed three bcm fuses in the engine bay, anticipating bcm disconnection when replacing a faulty blower speed control module in the hvac box. Once the blower speed module was replaced I needed to test it before reassembling the glove box. I forgot to replace the fuses and when I turned on ignition, the instrument panel flashed quietly until I realized the missing fuses and turned off ignition. After replacing the bcm fuses, everything returned to normal with blower speeds restored except for an error code (or more) turning on the SES light. Presuming it was for the bcm, I didn't decode it. Two or three engine cycles later the SES light went off on its own.

700+SL2 10-04-2017 02:27 PM

Re: Ground issue or BCM?
No blown fuses.
Cleaned the grounds and pawed around all wiring and connections. Nothing.
Aside from all the craziness the car runs and drives just fine except for yesterday. I fired it up and this time the light on the shifter was lit on 3 instead of park. Threw the shifter around but no change. Took it for a spin and it shifted up to 3rd and stopped there until a finally got to a point I could get it up to 50mph then it finally popped in.
Other than that odd thing itís been just fine.

fdryer 10-04-2017 03:41 PM

Re: Ground issue or BCM?
Reviewed the video today and it does seem like a bcm issue but as I mentioned previously, there are other areas to consider especially after bcm replacement resulted in the same symptoms. Was the instrument panel ever disconnected, checked is wiring harness for damaged wiring, chafing? Sometimes the simple act of disconnecting and reconnecting something can correct for corrosion issues of oxidized terminals. With all indicators seemingly flashing on and off in synch suggests a connection problem. Trial and error of covering all the basics is necessary for mystery problems.

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