Flakey dash gauges
Thread Starter
|
Junior User
Joined: Apr 2008
Posts: 70
Likes: 0
Flakey dash gauges
I've got a 88 F250 4x4 7.3L Lariat
My dash gauges are driving me nuts. I would be ok if they never worked but the work some days and not others.
For example: The Tach. Sometimes it doesn't read at all other times it reads about half what the actual RPMs are. Other times it works perfectly. I checked under the hood and it has a new tach sensor and the wiring looks great.
I have similar issues with the Oil Pressure and Voltage gauges. Fuel gauges are always wrong but I'm thinking that is the sending units in the tanks.
Any ideas on what to check before i go to the salvage yard and get a new dash.
My dash gauges are driving me nuts. I would be ok if they never worked but the work some days and not others.
For example: The Tach. Sometimes it doesn't read at all other times it reads about half what the actual RPMs are. Other times it works perfectly. I checked under the hood and it has a new tach sensor and the wiring looks great.
I have similar issues with the Oil Pressure and Voltage gauges. Fuel gauges are always wrong but I'm thinking that is the sending units in the tanks.
Any ideas on what to check before i go to the salvage yard and get a new dash.
Elder User
Joined: Aug 2005
Posts: 566
Likes: 3
From: New Jersey
Check your grounds to make sure they're ok. Also, check the connector on the back of the instrument cluster and make sure the contacts aren't corroded.
I've heard, but I'm not sure, that there's a voltage regulator that controls the dashboard gauges. I'll look into my schematics tomorrow to see if that's the case. My Mustang had a similar problem where the oil, fuel and voltage gauges would read high, then all drop down at the same time. I'd go from having almost a half tank of gas (according to the gauge) to having only a quarter tank, to give you an idea of how far the gauges moved when acting up.
I've heard, but I'm not sure, that there's a voltage regulator that controls the dashboard gauges. I'll look into my schematics tomorrow to see if that's the case. My Mustang had a similar problem where the oil, fuel and voltage gauges would read high, then all drop down at the same time. I'd go from having almost a half tank of gas (according to the gauge) to having only a quarter tank, to give you an idea of how far the gauges moved when acting up.
Lead Driver
Joined: Nov 2003
Posts: 6,900
Likes: 3
From: Campbell River, B.C.
Check your grounds to make sure they're ok. Also, check the connector on the back of the instrument cluster and make sure the contacts aren't corroded.
I've heard, but I'm not sure, that there's a voltage regulator that controls the dashboard gauges. I'll look into my schematics tomorrow to see if that's the case. My Mustang had a similar problem where the oil, fuel and voltage gauges would read high, then all drop down at the same time. I'd go from having almost a half tank of gas (according to the gauge) to having only a quarter tank, to give you an idea of how far the gauges moved when acting up.
I've heard, but I'm not sure, that there's a voltage regulator that controls the dashboard gauges. I'll look into my schematics tomorrow to see if that's the case. My Mustang had a similar problem where the oil, fuel and voltage gauges would read high, then all drop down at the same time. I'd go from having almost a half tank of gas (according to the gauge) to having only a quarter tank, to give you an idea of how far the gauges moved when acting up.
.And yes, both my trucks have a small silver rectangular capsule on the back of the instrument cluster. Pretty sure thats the regulator.
The symptoms in my case are the oil, fuel, and temp reading very high, or pegged. They will come back down if I tap the dash. From the symptoms described, I would check for a loose ground before trying to find a new cluster regulator
Thread Starter
|
Junior User
Joined: Apr 2008
Posts: 70
Likes: 0
I think the possible ground issue may be it. I tried tapping the dash and the gauges either stop or start working.
I'm showing my ignorance here.... how do I go about checking for a bad ground? I have a continuity tester and a test light.
I'm showing my ignorance here.... how do I go about checking for a bad ground? I have a continuity tester and a test light.
Lead Driver
Joined: Nov 2003
Posts: 6,900
Likes: 3
From: Campbell River, B.C.
It sounds to me like the problem may be an inperfect contact in the main cluster gauge connector on the back of the cluster. In some cases this has even been known to cause shifting problems with trucks of that era that came with automatic transmissions. A test light won't help with loose connectors, its just a matter of disturbing different connections until you find one that affects the problem, which I think you just did.
What you will have to do is remove the custer gauge, and unplug the main connector on the back to see if there is any dust or corrosion in there. Often simply unplugging it and reconnecting it will solve the problem. I would take a good light and magnifier to both sides of the connection to make sure the contacts are clean. Some electrical grease would help prevent this problem from happening again any time soon.
Senior User
Joined: Apr 2008
Posts: 326
Likes: 0
From: eaton ohio
Some electrical grease would help prevent this problem from happening again any time soon.[/quote]
megawatt turned me on to some stuff called noalox,got it at the local electrick supply,put it on some battery cables and they still look fresh that stuff would do the trick
megawatt turned me on to some stuff called noalox,got it at the local electrick supply,put it on some battery cables and they still look fresh that stuff would do the trick
Thread
Thread Starter
Forum
Replies
Last Post
gwhpnut
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
12
May 17, 2011 07:53 AM
