Gauge Problem

[rlp094]

So okay today I replaced the 0-60 oil pressure gauge with a new 0-120 one with a new 120psi sender. Problem is when I turn on the accessory switch, the oil, generator and fuel gauge go pinned to the right with engine not running. Rechecked grounds all looks good.
Any ideas?

 

[M35A2-AZ]

Did you make sure you plugged in the plugs in the right spot.

 

[rlp094]

They are in the same spot as before, but even with both oil wires off the other two gauges are still pinned.

 

[M35A2-AZ]

They are in the same spot as before, but even with both oil wires off the other two gauges are still pinned.

If that is the case you may have pinched a wire putting the panel back on.

 

[Flyingvan911]

Try switching the wires on the gauge and see what happens.

 

[rlp094]

Thanks for tips. Will be working on truck again this weekend.

 

[NDT]

Maybe the cluster is not grounded very well.

 

[rlp094]

All four corner screws are tight. Don't know if there is other grounding.

 

[clinto]

So, the way all those gauges work is..............

24V to the "IGN" side of the gauge.
The gauge body has to the grounded to the chassis. This is done via the mounting bracket that touches the panel, which grounds to the chassis via the 4 twist locks.
The "SEND" side is wired to the sending unit, other than the voltmeter, which only has the IGN input since it's just measuring the power coming in from the batteries.

So if all 3 are pegged, that's the same as pulling the wire off the sending unit and grounding it. So there's some sort of ground issue going on.

 

[rlp094]

Thanks, if it ever stops raining here in NJ i'm going to try to run a separate ground wire from the cluster to a good ground on the chassis and see if that works.

 

[rlp094]

Update: managed to crawl under the steering wheel and get a good look at the back of cluster. The spider harness looks klke its been pulled on and off before and is frayed in some areas. Ordered a new harness today and hoping thats it.

 

[rlp094]

Sorry for not getting back sooner, but yesterday I replaced the electric gauge with a manual one and i'm getting 60lbs cold. Which is why I switched to a 0-120 gauge. The grounds were cleaned and other gauges work normally. Probably should think about a new harness.
Want to say thanks to all who chimed in for your help. This is a great site!