The higher the fuel level or oil pressure, the lower the resistance. I really need help on this one. The reason all the meters are damped is because the senders do not have a very constant resistance. Jeep stays in garage - new toyota tundra sits outside! So far every item I've gotten from Omix-Ada have been very good quality. It has to be a ground or short somewhere or the company keeps sending me defective gauges. There must be good metal-to-metal contact; free of rust, corrosion, paint, and oxidation.
Do your gauges sometimes work and then not? About the Sending Units The oil pressure sender is similar to the fuel gauge sender. If the Ohm reading increased from zero in a; b; c, above then you know where the short is when you remove the wire and the Ohm reading jumps higher. The Temp gauge gets it power from the regulated output of the fuel gauge so the Jumper Strap connecting the A terminals of the fuel and Temp gauges must be left intact. The oil pressure sender and fuel sender are both electro-mechanical devices but the temperature sender is not. Fuel Gauge Fuel Gauge Tank 1966-1973 Jeep ® Commando Stainless Steel Gauge Cluster Bezel. This gauge has a built in current regulator that limits the amount of current flowing thru the gauges and sensors. I have used jumper wires from the sending units and grounds to make sure it is not the wires and it is hit and miss.
There are some slight variations with the Jeeps built from '72-'75, but starting in '76 things remain pretty consistent for 10 years. It should be pulsing and averaging about 5 volts. View from inside of Fuel gauge illustrating the mechanical voltage regulator. Larry Van Every has written a great trouble shooting guide for you. Note: Imported, after-market gauges have these ranges reversed. I really want my stuff to work correctly too! Like a light bulb, it will work no matter which way the current flows.
If the gauge shows no activity, then the gauge is bad. Note: there have been reports of this regulated voltage being as high as 7-9 volts with no loss of gauge function. Plug-In picture: Oil Guage Temp. When i test it the voltage meter goes crazy, anywhere from 1 to 7 volts fluctuating at the speed of a machine gun which i am told is what it is supposed to do but doesn't seem right Anyway, any help would be greatly appreciated, i don't like getting my butt kicked by a temperature gauge. I have a cheep one but do not understand it or the settings. I have had a major Transmission total rebuild, I put everything new in it! If 12 Volts is applied to the temperature gauge's A terminal, it will cook the temp gauge! It is easiest to test the sending unit by temporarily plumbing in a good mechanical gauge. It has worked a few times using different sending units, I bet I have bought 20 trying to get it to work consistantly I have a Mechanical installed Mid-block, where a thermal vacuum switch once was.
The dampening mechanism is basically some thick grease on the movement's pivot points. . The second is the speedometer housing itself. This process repeats itself over and over again. With an ohmmeter check the resistance between the post and ground. Once you have the process down, it's an hour job, tops! We can even discuss the lamp load test, a simple, homespun tool that can unearth the deepest gremlins, like an open or weak wire or circuit that seems to appear intermittently. A - fuel guage side of jumper strap.
My fuel gauge works fine but temp gauge dosn't work, at zero. I am starting to pull my hair out because of this, hoping someone will be able to give some advice, the only thing I am not sure if I am testing properly is the jumper wire that goes from the fuel gauge to the temperature gauge. The tab style connector and wire is a ground to the frame. I thought about looking for the one i pulled off my Jeep but i think i already gave it away a long time ago. Got new jumper with guages.
Do you keep blowing your fuse? The temperature sender is a temperature dependent resistor Thermistor. The meter movement in all the gauges have a built-in dampening mechanism which keeps the needle from bouncing around. I can even make suggestions here if you're shopping for the tool. The higher the fuel level or engine oil pressure, the lower the resistance. I know the gauge is working because when i ground out the signal terminal on it the gauge climbs to the hot position. I had one electronics expert tell me it might be closer to 7. It is upright and cylindrical with one wire attached to its center post.
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. Either way, there is only one circuit loop inside the temperature gauge. If it reads 0 volts, it has been burnt out. As the temperature increases the resistance drops. If it does move, the sending unit is bad. Totally Cold High Resistance Slightly Warm 73 ohms Beginning of Band 36 ohms End of Band 13 ohms Hot 9 ohms If an appropriate resistor is connected to the S terminal of the temperature gauge and to ground, the above resistance can be used to check the gauge.
At the end of this strip is a contact that opens and closes as the bi-metallic strip bends. Off comes the power lead to the oil gauge. If it reads 12 volts, the regulator in the Fuel Gauge is bad. Fuel Gauge The fuel gauge should have the following resistances. Morris 4x4 Center®, Morris Motors Co.