Gauges all read incorrectly and vary with signal

[Lgarretto]

I know it's dark. The little silver piece on the top right corner of the connector is a bolt on Terminal that has been cut. I'll have to trace the ground from B the cluster and fine where it had been moved to

 

[thinger2]

Ground straps from the back of the passenger side head to the firewall and from the firewall to the frame.
After ranting about grounds several times in the last few days I took a look at mine and found this little gem.
Its only a couple of years old.
Get 2 5 buck each 4 gauge 24 inch long battery cables with ring eyes at both ends. Clean all connections back to bare metal and bolt em on.
Just be carefull with the stud coming out of the firewall. Its pretty wimpy so dont strip it.
I plan on putting a decent through bolt on it eventually.
Also check out the grounds under the dash and on the manifold

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[Ehall8702]

Oh I forgot to tell yall truck info. I apologize. I have an 89 swb with a 350 tbi and a 5 speed.
And I will go check the ground right now

Those things are horrible with voltage drops. Lots of em voltage dips severly with blinker. Usually a "big 3(4)" upgrade resolves most issues but u have a bad found somewhere AND a voltage issue too.

 

[Lgarretto]

I think 30-40psi oil pressure is probably normal. Which is what it reads. So if it's just a bad ground that's an easy fix and I'll happily do it. I know my temp gauge is incorrect. I'd like that to be considered rrect for safety reasons. Don't really wanna have to fix a head gasket or worse. And the gas gauge I am sure needs a new sending unit or something. It doesn't move with the blinker. I'll check the ground strap in the engine bay. I haven't found the ground for the gauges yet.

 

[Supercharged111]

Gas gauge could well be a sender. Mine was only partially attached to the bucket. Try some fuel system cleaner and see if the gauge doesn't start acting right.

 

[Lgarretto]

Well fellas I may just leave it all. The truck runs fine. Somehow. The ground for the gauge cluster has been cut, the ground on the firewall under the heater hoses isn't there, and the ground on the passenger side of the frame that it goes to also doesn't exist. A ground for something is wrapped around a screw under the dash under the fuse panel and there's a big wad of wires there as well that I'm pretty sure isn't factory. And several are cut anyway. So tracing this issue for me would probably mean rewiring literally every electrical item on the truck. I don't understand why someone would do all this. But it's too cold out today to bother with it

 

[Lgarretto]

Oh also there's no ground direct from the battery. That's been cut. And there's no ground I have found yet on the engine either.

 

[thinger2]

It is the grounds, it is the grounds, it is the grounds....
You cant diagnose a damn thing on these without them being grounded.
Its the grounds...
Fix them before you chase your tail
Its the friggen grounds

 

[F4U-1A]

HAL! HAL! Open the pod bay door!

 

[F4U-1A]

Grounds, Grounds. I use coffee grounds for my Home Brew. That is why I am wide awake.