So I went to use the truck, battery dead... well it had sat for a month, no suprise. Got a known good battery, dropped it in, crank no start.
So looked at the dash and turned the key and saw:

No gauage sweep
No CEI light up
No Security light flashing
no lights at all except battery and seat belt

had to go so I walked away from it

that evening I without thiniking used the dash switch (guage cluster dimmer) to turn on the cabin lights, stuck the key in and it fired right up
Guage swept
CEI turned on then off
Security light verified the key and went out

Went to give the truck a test drive, turned the interior lights off and:
Guages shut off

so I started testing things
All fuses in both fuse boxes good
started checking relays: noticed the battery saver relay was pulsing. Replaced with a new one. New one did the same thing
windshield wipers will only work when the dome light is turned on
door ajar light works with dome light turned on, but not with it turned off...


will only start with interior lights turned on, but once it is running it appears to drive normal when interior lights are off with the exception of none of the instrument cluster guages working

Do I have a bad ground that is backfeeding through the dimmer switch?

I do not want to start throwing parts at this truck. It is a 2000 F150 with 190k on it, and until now it has been rusty but trusty

any thoughts would be appreciated

Thanks,
Steve

 

Dash 'panel' depends on a ground to complete their operation ……..except the Alternator charge lamp.
This lamp gets power through the ignition switch and it's ground control from the Alternator regulator so is not part of the rest of the panel power.
The interior light control is also separate.
The GEM has no control over the dash 'primary' power functions except to various lights such as 4high, 4 low etc.after the motor is running.
Likely a ground issue or even the ignition switch that supplies most of the power to the affected areas. The charge lamp lights so ign sw may not be a high suspect.
Many light actions are timing dependent when they light and under what conditions.
Ignition to Run is a check-out of the panel so a missing ground is very likely.
Good luck.

 

Bad ground. Pull the LH kick panel and inspect the ground studs.

 

I will check out the grounds, appreciate the input and will update when I figure it out. Thanks!

Steve

 

Wanted to update everyone. projectSH089 was correct. It was a bad ground underneath the LH kick panel. Very much appreciate the help

Thanks again.
Steve

 

Got a picture, by chance?

 

I did not take a picture. It was the lower ground under the panel, to be honest the truck is so rusty I should just retire it.... part of what I discovered is that it is a flinstone mobile under the kick panel and rubber floor mat. The fram is solid, but everything else is shot....

Steve