i really dont know where should i post this thread ... if i am wrong advance apology.


please see the picture below ...



as you can see the Temp. and Fuel gauge's are not working ... my mechanic advised me to purchase a new one ... and its so freakeeenn expensive ... i really dont want to buy a new one ... i checked for a used one cant find it ...
is this thing fixable?? ... the guy told me that some was playing with cables inside ... so its burned ... need to buy a new one wat do i do wat do i do
help please!!
(btw its 1998 blazer 4X4)

 

First, use "MSPaint" to open a photo. It will show in the true size of the photo. If the photo is giant and off your screen, do the following while you have it open;

a) Image then Stretch
b) put in 20% for H and 20% for V and click OK. Then Save.

Next, check this; http://dl.dropbox.com/u/837001/Blaze...3%20of%204.gif

You can see that (on a 1997) the Temp Fuel and Oil Pressure share the same power and ground, but each has a single wire true the multi plug. In 97 those were 7-30-35.

While the oil and temp sensors hook to the gauge, the fuel sensor comes from a computer. That computer also tells the overhead console how much fuel you have left so it can calculate your "RANGE". If you have this console, what does it think your RANGE is? IF "Low" even when your tank is full, then the problem is in the tank or between tank and computer.. If overhead says 200 miles range, but gauge says empty tank, problem is gauge or between gauge and computer.

I doubt they are the same numbers on the 99. but if you pull the panel, you can trace the circuit lands to be sure.

With the gas tank full, plug pulled and car "idling" use an Ohm-meter to check between chassis ground the each of the three wires. Someone here can tell us the values, but I'm thinking they should all be less than 5000 ohms or 5kohms. If they are in a similar range, prob is in your gauges. If Oil is low and the other two are very high, problem is wires or sensor.

Another test would be to make a tiny nick i each of the three wires and short them to ground and see if the gauges respond.

This is not Rocket Surgery. You can fix it!

 

A full feature scan tool should be able to tell you whether it is the gauges or the sending units/wiring. All of the data for the cluster comes through a serial communication bus.

 

ok i will do the scan thing tomorrow ...
thanx man

 

swartlkk; Does the temp and oil pressure go thru the computer before going to the dash?

I was under the impression the computer on 96-99 has no oil pressure indication at all and that the temp in the computer comes from the coolant sensor near the Thermostat while the temp gauge runs on a sensor located elsewhere.

Also, a full featured scanner is quite expensive to fix a simple gauge problem. Ohm-meter should do the trick.

 

There is no analog ECT sensor on the 98+ trucks. Everything is pushed via the serial bus to the cluster and interpreted via the IC Logic circuits.