The Ford Barn

jaxV8carz · 03-16-2011, 12:35 PM

This is on Shoebox also...
I recently replaced the instument cluster on my '51 Ford. I reused my gauges and reset the odometer to match the existing reading. I took photos of the back side to be sure all was reconnected the same way. The '51 has 2 jumper bars to supply power to fuel, temp, and oil. Then each gauge has a wire that goes to its respective sender. I put the unit back in and switched on ignition and started the engine. All works correctly except the oil indicator goes to max and stays there. This is with the engine running or not. With the ignition switch to OFF, the needle goes back to zero. I even disconnected the wire at the oil pressure sending unit with the engine running and nothing changed. I'm perplexed. What is going on? Any ideas? Thanx!

Henry/Kokomo · 03-16-2011, 03:09 PM

I'd say there is a short in the circuit. First guess would be a bad sending unit going straight to ground. If there's no resistance in the sending unit, there's nothing to "regulate" the gauge. Good luck

Barlea · 03-16-2011, 09:27 PM

"disconnected the wire at the oil pressure sending unit with the engine running and nothing changed." Probably not the sending unit then. More likely grounded between gauge and sender, not likely to be good for the gauge. ..B.

4dFord/SC · 03-16-2011, 09:31 PM

Just a guess, but recheck how the gauge is mounted in the instrument panel. It may be grounding there.

325w · 03-16-2011, 09:32 PM

Maybe a lack of ground ??

BillM · 03-16-2011, 09:55 PM

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Try a temporary wire from the gauge to the sender; you may have an open circuit.

Juergen · 03-17-2011, 07:37 AM

Quote:

Originally Posted by jaxV8carz

This is on Shoebox also...
I recently replaced the instument cluster on my '51 Ford. I reused my gauges and reset the odometer to match the existing reading. I took photos of the back side to be sure all was reconnected the same way. The '51 has 2 jumper bars to supply power to fuel, temp, and oil. Then each gauge has a wire that goes to its respective sender. I put the unit back in and switched on ignition and started the engine. All works correctly except the oil indicator goes to max and stays there. This is with the engine running or not. With the ignition switch to OFF, the needle goes back to zero. I even disconnected the wire at the oil pressure sending unit with the engine running and nothing changed. I'm perplexed. What is going on? Any ideas? Thanx!

I think most of us feel that "nothing changed" means that the oil pressure went to max scale again. If so it is not a problem with the sending unit. I would disconnect the wire at the gauge which goes to the sending unit. If it still maxes out, the problem is somewhere in your gauge/cluster.
Take the gauge out and apply power to it and ground the gauge mounting point. It should not max out. If it does, the gauge is bad (I would guess points are stuck).

jdl · 03-17-2011, 09:39 AM

Here is a diagram for you, check it against your cluster..

jaxV8carz · 03-17-2011, 01:14 PM

Lots of great info, guys!! Thanx so much. I disconnect the wire to sender and gauge still maxes out. I can play around with the jumper bar connection and it will max out and then it won't. As much as I HATE to, it looks like I may need to pull the cluster. But first I'm going to try to remove the 2 screws that hold the individual gauge in and try to eliminate in direct shorts to ground there. All other gauges are doing the right thing. Jack
The verdict is in.........I went back at it and loosened the 2 nuts that hold the gauge to the mount plate, wiggled it a bit, crossed my toes, did a little prayer, tightened them back up, and it would appear that I eliminated the gauge to ground. Now the needle doesn't move when switched ON, but goes up to a normal reading upon starting. I may be part Irish...maybe it's the luck of the Irish helping out. Thanks to you all. Jack

03-16-2011, 12:35 PM	#1
jaxV8carz Member Join Date: May 2010 Location: Raleigh NC Posts: 33	Need gauge help... This is on Shoebox also... I recently replaced the instument cluster on my '51 Ford. I reused my gauges and reset the odometer to match the existing reading. I took photos of the back side to be sure all was reconnected the same way. The '51 has 2 jumper bars to supply power to fuel, temp, and oil. Then each gauge has a wire that goes to its respective sender. I put the unit back in and switched on ignition and started the engine. All works correctly except the oil indicator goes to max and stays there. This is with the engine running or not. With the ignition switch to OFF, the needle goes back to zero. I even disconnected the wire at the oil pressure sending unit with the engine running and nothing changed. I'm perplexed. What is going on? Any ideas? Thanx!

03-16-2011, 03:09 PM	#2
Henry/Kokomo Senior Member Join Date: May 2010 Location: Kokomo, Indiana Posts: 1,731	Re: Need gauge help... I'd say there is a short in the circuit. First guess would be a bad sending unit going straight to ground. If there's no resistance in the sending unit, there's nothing to "regulate" the gauge. Good luck

03-16-2011, 09:27 PM	#3
Barlea Senior Member Join Date: May 2010 Location: West Central Alberta Posts: 441	Re: Need gauge help... "disconnected the wire at the oil pressure sending unit with the engine running and nothing changed." Probably not the sending unit then. More likely grounded between gauge and sender, not likely to be good for the gauge. ..B.

03-16-2011, 09:31 PM	#4
4dFord/SC Senior Member Join Date: May 2010 Location: Columbia, SC Posts: 1,579	Re: Need gauge help... Just a guess, but recheck how the gauge is mounted in the instrument panel. It may be grounding there.

03-16-2011, 09:32 PM	#5
325w Senior Member Join Date: Feb 2011 Location: Arlington, Texas Posts: 379	Re: Need gauge help... Maybe a lack of ground ??

03-16-2011, 09:55 PM	#6
BillM Senior Member Join Date: May 2010 Location: Everett, WA Posts: 504	Re: Need gauge help... Sponsored Links (Register now to hide all advertisements) Try a temporary wire from the gauge to the sender; you may have an open circuit. __________________ My web page: http://myplace.frontier.com/~wgmumaw/

03-17-2011, 09:39 AM	#8
jdl Senior Member Join Date: May 2010 Location: California Central Coast Posts: 931	Re: Need gauge help... Here is a diagram for you, check it against your cluster..

03-17-2011, 01:14 PM	#9
jaxV8carz Member Join Date: May 2010 Location: Raleigh NC Posts: 33	Re: Need gauge help... Lots of great info, guys!! Thanx so much. I disconnect the wire to sender and gauge still maxes out. I can play around with the jumper bar connection and it will max out and then it won't. As much as I HATE to, it looks like I may need to pull the cluster. But first I'm going to try to remove the 2 screws that hold the individual gauge in and try to eliminate in direct shorts to ground there. All other gauges are doing the right thing. Jack The verdict is in.........I went back at it and loosened the 2 nuts that hold the gauge to the mount plate, wiggled it a bit, crossed my toes, did a little prayer, tightened them back up, and it would appear that I eliminated the gauge to ground. Now the needle doesn't move when switched ON, but goes up to a normal reading upon starting. I may be part Irish...maybe it's the luck of the Irish helping out. Thanks to you all. Jack Last edited by jaxV8carz; 03-17-2011 at 01:47 PM.