Instrument cluster has lost it's mind....

[Chilledspode]

Das Boat has pushed my button one more time! Frick.
I tried a number of searches but either I am describing it differently or this is a bit unusual.
All the gauges are affected in some way but its complicated to describe. Lets take the charging gauge - while running and driving it is showing min low scale at around 9v and over two seconds it climbs to about 11v then pulls back to 9v again (like you pulled the power from the gauge) over and over. Oil presssure is min low scale and cycles up and down, speedo is jumping on 2 sec interval as well.
Turn signals exterior all work properly but dash indicators do not light when running lights are off.
Turn running lights on and all gauge needles fall to full low scale, like you turned them off, even the tach while running! Both turnsignal indicators in the dash come on solid.
Security light has been coming on recently but hasn't yet produced any starting or driveability issues - is the security somehow involved?
I have never seen anything like this and have no idea what might be causing this but hoping someone has and can give me some suggestions.
Thanks
Baffled....

 

[magimerlin]

Check your battery directly first... all those issues can be symptoms of a low voltage and or dead(internally) battery. The gauges need the main power to be at least 12v to work "properly"... so I'd get the battery checked first. Free to get done at most all parts stores. And get the alternator checked to just in case.

Sent from my SAMSUNG-SM-G891A using Tapatalk

 

[89RCLB]

Agreed with what magimerlin posted...

I've also seen a bad ground (or lack thereof) at the cluster itself cause issues like this.

 

[Chilledspode]

Thanks, will check those things out today. Its a 2 year old gel battery so I am expecting it to be good but I haven't checked in on the alternator in a very long time.... Also going to disconnect the battery for awhile and reset everything just because Cheers

 

[Chilledspode]

Agreed with what magimerlin posted...

I've also seen a bad ground (or lack thereof) at the cluster itself cause issues like this.

Is the cluster gounded through the wiring harness or a more local direct chassis ground? Cheers

 

[89RCLB]

Is the cluster gounded through the wiring harness or a more local direct chassis ground? Cheers

It should be but I can't say for certain on your year truck. Maybe @east302 can post a diagram for you.

In the mean time you might want to check your engine bay grounds: Battery to fender, battery to engine, engine to chassis, frame to cab (this is the ground I would look very closely at).

Hope this helps.

 

[Chilledspode]

On it! Will report back when I have new info. Thanks for the suggestions.

 

[Chilledspode]

Initial results. 12.6v off after sitting overnight, 14.8v charging at the battery terminals sfter starting. This seems normal to me.
While running the charging/voltmeter gauge is only showing around 9v (vs 14v as seen by the meter at the battery) and the other gauges are not in their normal position and are rotated towards minimum reading.
The most reproduceable weird is as soon as you turn on the running lights on every gauge collapses as if you powered them off the whole cluster the security light comes on for a few seconds and both turn signal indicators come on solid.

Off to work through grounding checks....

 

[east302]

It looks like it grounds at #103 and 104. Here is 103 near the thermostat, not sure where 104 is other than the description below.

Hope this helps.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

Sent from my iPhone using Tapatalk

 

[Chilledspode]

Nicely done, thank you. Let me dig into this, I am sure it will be helpful as I get into this issue some more.