Where is the fuel gauge on a Jeep CJ?
The fuel gauge should have the following resistances The fuel sending unit wires are located on top of the gas tank where they are hard to get to without dropping the tank. The fuel sending unit should have a pink wire with voltage on the isolated center post.
Why does the CJ gauge read higher with higher oil pressure?
The higher the fuel level or engine oil pressure, the lower the resistance. With less resistance, more current flows and the gauge reads higher. The oil pressure sender and fuel sender are both electro-mechanical devices but the temperature sender is not. The temperature sender is a temperature dependent resistor (Thermistor).
How can I tell the ohm range of universal fuel sender?
With the multimeter set to the Ω setting put the red probe on the post that is the gauge lead and put the black probe on the ground post or on the body of the fuel sender. Record your readings with the fuel sender in the empty position and in the full position. Those two numbers will tell you the ohm range is of your sender.
How is the gas gauge in the instrument cluster?
The gas gauge in the instrument cluster is the visual indication of activity in the fuel tank and sending unit. Some gas gauges are directly controlled by voltage feedback from the sending unit, while others are controlled by the instrument cluster, which itself gets voltage information from the sending unit.
Why is my YJ gas gauge not working?
YJ gas gauge not working! Having problems with the gas gauge? It seems as more time than not the heart of the problem lies in the gauge cluster its self. All those copper contacts usually have some corrosion film impeding proper contact. Take out the screws that holds the dash trim in place.
How to diagnose fuel gauge problems in Jeep?
Ya know, the hot sauce that you put on soup beans or a sandwich. Brands such as Tabasco or Louisiana hot sauce are the most common. Just rub a light coat on the contacts and allow it to sit for a few minutes. Then with a clean rag wipe it all clean. Look at that copper shine! Check out the video below how I did my cluster.
Why do I need a fuel gauge schematic?
Not only that it also helps seal out water from those nice clean connections you established for your gauges. It helps lessen the reasons why your Jeep fuel gauge problems should re-occur. Need a schematic for the fuel pump connection?
What does grease do to a fuel gauge?
That grease does not hinder the electrical connection at all. What it does do is prevent more corrosion from forming. Not only that it also helps seal out water from those nice clean connections you established for your gauges. It helps lessen the reasons why your Jeep fuel gauge problems should re-occur.
How does the oil pressure sender work on a Jeep CJ?
The oil pressure sender is similar to the fuel gauge sender. The mechanical parts are different, but after that it is basically a coil of resistance wire wrapped around a card and the wiper moves across the winding to change the resistance. The higher the fuel level or engine oil pressure, the lower the resistance.
What kind of sender does a Jeep CJ have?
The temperature sender is a temperature dependent resistor (Thermistor). The type in the Jeep is a NTC (Negative Temperature Coefficient) which means that as the temperature goes up, the resistance goes down. From the passenger side which is left to right in the picture above. Fuel Gauge S Terminal – pink wire (from fuel sender)
Why are the senders dampened on Jeep CJ gauge?
The meter movement in all the gauges have a built-in dampening mechanism which keeps the needle from bouncing around. The dampening mechanism is basically some thick grease on the movement’s pivot points. The reason all the meters are dampened is because the senders do not have a very constant resistance.
The fuel gauge should have the following resistances The fuel sending unit wires are located on top of the gas tank where they are hard to get to without dropping the tank. The fuel sending unit should have a pink wire with voltage on the isolated center post.
The oil pressure sender is similar to the fuel gauge sender. The mechanical parts are different, but after that it is basically a coil of resistance wire wrapped around a card and the wiper moves across the winding to change the resistance. The higher the fuel level or engine oil pressure, the lower the resistance.
What are the terminals on a CJ gauge?
Fuel gauge S terminal has a pink wire and runs to the fuel sender. Fuel gauge A terminal is the 12V side of the jumper/regulator strap. Fuel gauge I terminal has a red wire and is the 12 V ignition hot wire. Temperature gauge A terminal is the 5V side of the jumper/regulator strap.
How can I check the CJ gauge voltage?
Run an appropriate resistor to the S terminal of the fuel gauge and to ground and check the readings. The temp gauge has the following resistance. A volt meter can be used to measure the voltage between the A terminal of the Temp gauge and ground. It should be pulsing and averaging about 5 volts.
Where are the ResistanceS on the fuel gauge?
The fuel gauge should have the following resistances … The fuel sending unit wires are located on top of the gas tank where they are hard to get to without dropping the tank. The fuel sending unit should have a pink wire with voltage on the isolated center post.
What happens when CJ gauge does not move from empty?
If the gauge does not move from EMPTY either the wiring has an open circuit (no voltage, or no connection to ground) or he gauge is bad. If it does move, the sending unit is bad. The sending unit can be checked with an ohmmeter to measure the resistance between the round sender post (pink wire) and ground.
The gas gauge in the instrument cluster is the visual indication of activity in the fuel tank and sending unit. Some gas gauges are directly controlled by voltage feedback from the sending unit, while others are controlled by the instrument cluster, which itself gets voltage information from the sending unit.
The fuel gauge should have the following resistances … The fuel sending unit wires are located on top of the gas tank where they are hard to get to without dropping the tank. The fuel sending unit should have a pink wire with voltage on the isolated center post.
If the gauge does not move from EMPTY either the wiring has an open circuit (no voltage, or no connection to ground) or he gauge is bad. If it does move, the sending unit is bad. The sending unit can be checked with an ohmmeter to measure the resistance between the round sender post (pink wire) and ground.
The temperature sender is a temperature dependent resistor (Thermistor). The type in the Jeep is a NTC (Negative Temperature Coefficient) which means that as the temperature goes up, the resistance goes down. From the passenger side which is left to right in the picture above. Fuel Gauge S Terminal – pink wire (from fuel sender)
When did the AMC Jeep CJs come out?
This article only covers gauges and sending units used in the AMC Jeep CJs built from ’72-’86, but some of this information will be useful for owners of other Jeeps. There are some slight variations with the Jeeps built from ’72-’75, but starting in ’76 things remain pretty consistent for 10 years.