Welcome to the Land Rover Forums - Land Rover Enthusiast Forum.
If this is your first visit, be sure to check out the FAQ by clicking the link above.
You may have to register before you can post: click the register link above to proceed.
To start viewing messages, select the forum that you want to visit from the selection below.
What I did was remove the gauge faces, with the needle and motors attached as one, off of a 03/04 style instrument cluster and place them over into my older 00' style unit to avoid having to get the odometer programmed to display correct mileage.
The tach and the speedometer work fine, however the temperature gauge is pinned at the bottom and does not move, and the gas gauge is pinned on full, also not moving.
Any idea why? I noticed the new 03/04 model gas and temperature motors have a resistor on each one, and the older model gas/temp motors do not.
__________________ Land Rover- The Best 4x4xFar
Last edited by Street Wolf; 01-26-2012 at 03:00 AM.
RAVE shows the instrument pack as a single unit. It has a microprocessor of its own and communicates with the the ECU and gets some sensor inputs. The microprocessor does things like smooth out the display, so sloshing fuel does not make the fuel guage flick wildly on rogh roads. From the RAVE:
General
The instrument pack consists of four analogue dials, four warning lamp packs and a Liquid Crystal Display (LCD) odometer. The four dials are used to indicate:
Road speed.
Engine speed.
Fuel tank level.
Engine coolant temperature.
The dials are driven by a microprocessor from information received from the serial communication link. Information input is received as either:
Digital.
Analogue.
Pulse train.
Pulse Width Modulation (PWM).
So in the example of the temp gauge, the coolant sensor is attached to the ECU, which converts it to digital (the degrees shown on your scanner or Ultra Guage), sends it over to the instrument pack, where it is converted back to an analog signal to make guage motor move. Engineers run amok.
The builders of the instrument pack most likely had some sort of design change that does nothing different on the outside, from the respect of connector pin to pin, but changed how parts inside were treated. The resistors, as an example, could be used to "adjust" the function of a motor, so that one motor could be stocked and set to work for either instrument position.
Now, the resistors normally have colored stripes. Are colors identical on each? Write down the colors and which gauge they are on. Is the resistor attached to the motor terminals in parallel (across it)? This is a "current shunt" resistor, and the value of it should be reduced to move the meter pointer back to where you want it. Right now more current is going through the motor itself than needed, so gauge is pinned.
It would be possible to swap values of resistors to "calibrate" things. As an example, we know when engine coolant is 195 F the ECU wants the temp needle in the middle. And with a full gas tank you know where the gas gauge should be. Since meters are being over driven, in all likelyhood you will need to put on a different resistor, or add another resistor in parallel with this one. A starting point would be another resistor with identical colors.
Temp/Fuel Gauge Issue
