cluster not reading right

[obs902500]

I have a 90 c2500 with moon gauges, bought the truck then blew a head gasket and replaced it myslef, got the truck running and had been running good since then but recently my gauges have been acting weird, at first my oil pressure read 50 psi at idle (i changed oil pump to a high volume one) now it’s reading no more than the first mark on cold and goes all the way down when warm causing the check gauges light to come on, hooked up a mec gauge and oil pressure reads 50 cold around 20 hot on idle so that’s good, my battery voltage gauge also started reading just at the first mark not passing it, i just replaced battery, starter, and alternator, then my gas gauge started reading the same not going passed the first mark when full and gauge fully disappearing when low tried to look at grounds but not sure what could be happening all grounds look like they are connected good, any help would be really appreciated

 

[obs902500]

also forgot to mention i replaced the oil pressure switch and fuel pump aswell with sender, also the fact that the gauges move makes me kinda mark off the sensors/switch being bad but not too sure still

 

[GoToGuy]

You don't look at the grounds. You remove them clean the attachment areas, check the ring eye, wire for corrosion. Then reattach.

 

[someotherguy]

You don't look at the grounds. You remove them clean the attachment areas, check the ring eye, wire for corrosion. Then reattach.

This, and be sure none are missing/broken/disconnected. Service manual downloads in the Engines section have wiring diagrams including locations of these connections.

Richard

 

[obs902500]

i will remove the grounds once i get home i am out of state at the moment but thank you hopefully the grounds are the problem it’s kinda risky to not know how much gas u actually have

 

[obs902500]

You don't look at the grounds. You remove them clean the attachment areas, check the ring eye, wire for corrosion. Then reattach.

hey guys, so i found the ground for the cluster and it was connected good, i still took it off and cleaned it made sure it was still in good condition and screwed it back down, my cluster is stil the same i took out the cluster because i couldn’t hold back just seeing behind it and it also looks like it’s in decent condition nothing
broken or weird (expect like half of the bulbs are missing which i’m buying asap to put them in) but i’m still super stuck and confused about this, the sensors/ switches keep coming back as a reason but even then i’m not sure if the battery voltage even has a fuze or switch to check any help with this would be highly appreciated

 

[obs902500]

also forgot to mention i have an aftermarket radio, added 2 extra speakers in door panels and 2 tweeters, aswell as with a sub, would that cause any problems with the rest of the truck? i wired the sub correctly ( a positive from a battery terminal and ground on seat bolt)

 

[1998_K1500_Sub]

i found the ground for the cluster and it was connected good

Check the grounds that connect the frame to the body and the body to the engine. They're located on the passenger's side in the engine compartment, just behind / nearby the exhaust manifold's connection to the downpipe.

There is likely also a ground connection directly to the frame for the fuel pump, in proximity of the fuel tank. Check this now, before it becomes a problem for you later.

You can find these grounds mentioned in the factory service manual for your year.

If your vehicle's been in CA all its life, the grounds may be in good condition; in the northern states the salt exposure can cause problems.

Just the same, check all those mentioned. Some prior owner may have changed / removed them for some reason (e.g., during an engine replacement or for other reasons). They need to be in-place and functional for the electrical system to work as designed.

There are many other ground connections in the system, but these should be checked whenever there's a problem.

Ideally, "checking" means measuring the voltage drop across the ground strap / ground wire by using a voltmeter when the electrical system is under load. For now though, simply confirming they're in place and connected properly is a start.

 

[obs902500]

Check the grounds that connect the frame to the body and the body to the engine. They're located on the passenger's side in the engine compartment, just behind / nearby the exhaust manifold's connection to the downpipe.

There is likely also a ground connection directly to the frame for the fuel pump, in proximity of the fuel tank. Check this now, before it becomes a problem for you later.

You can find these grounds mentioned in the factory service manual for your year.

If your vehicle's been in CA all its life, the grounds may be in good condition; in the northern states the salt exposure can cause problems.

Just the same, check all those mentioned. Some prior owner may have changed / removed them for some reason (e.g., during an engine replacement or for other reasons). They need to be in-place and functional for the electrical system to work as designed.

There are many other ground connections in the system, but these should be checked whenever there's a problem.

Ideally, "checking" means measuring the voltage drop across the ground strap / ground wire by using a voltmeter when the electrical system is under load. For now though, simply confirming they're in place and connected properly is a start.

thanks for the reply, the vehicle has been in california it’s whole life and still living here, i was checking those 2 grounds on passenger side, one from the back or the head to firewall, the other from frame to firewall on the same stud, they are cleaned now and still in good condition, also i replaced the fuel pump about a month ago and the ground strap was also in really good condition now i’m just thinking it’s my cluster since the truck did sit for about 5 years before i bought it, i am going to take it apart see what i can mess around with or get a new one and hope it’s better, thank you for the help

 

[1998_K1500_Sub]

Some

get a new one and hope it’s better

Some people replace the moon gauges with needle gauges from a later model year. You might consider that option.