Jpr5690

iTrader: (13)

HA HA ITS PRETTY DAM EASY !!!!

IF YOU ALL ARE INTRESTED LET ME KNOW (JPR5690@AOL.COM) I WILL SAY IT DOES TAKE SOME WORK ON THE GAUGE CLUSTER' CIRCUIT BOARD BUT ITS REALLY NOT THAT BAD

Roadhouse

iTrader: (8)

Was it broken or did you mod it?

crazymofo1986

iTrader: (3)

lets c a write up

snketr

iTrader: (3)

2MuchRiceMakesMeSick

Im interested why dont you post up the info?

Jpr5690

iTrader: (13)

ok here it comes.... BTW this came from a another guy

also i modifed his instructuions alot since they did not seem to work 100%
but the way i did mine is pretty dam easy looks good and works great ....

Jpr5690

iTrader: (13)

Temp Gauge Mod

• Take a 200 ohm resistor and unplug the temp sensor, and hook the resistor to terminals “A” and “B” of the plug, turn the ignition on and read the temp gauge it should read about 210* F. (maybe a little over, but memorize were the needle is)
• Get a temp sensor from a (98 F-body)
• Get a temp sensor terminal plug from a (98 F-body)
• Hook a 20 Gage wire to terminal “C” of the new sensor plug. (Terminals “A” is sensor ground, and “B” is sensor signal to PCM.)
• Pull the two wires from terminals “A”, and “B” from the old sensor plug and replace them into terminals “A”, and “B” of the new sensor plug. (Wires go from terminal “A” to ”A”, and “B” to ”B”)
• Place new temp sensor into the engine head.
• Pull the Gauge cluster out.
• Run the other end of the new wire from terminal “C” through the fire wall and into the cab, run the wire behind the dash and into a hole behind were the gauge cluster goes, put an insulated female connector plug on the wire.
• Cut another length of wire and put an insulated male plug on one end, and the other end get soldered to the gauge cluster circuit board.
• Take out the two torques screws that’s holding the back cover on, pull the back cover off.
• Take out the one torques screw that by the plug pack terminals that holding the circuit board on, “very carefully pull the circuit board off.” (you need to go around the edges and gently pull up with your fingers while unsnapping the tabs.)
• Take a razor and on the back of the circuit board (the pic. shows were ) make a cut next to the jumper solder joint on the printed circuit layout, make another cut about a1/8” of an inch down from the first cut on the printed circuit layout so that a 1/8” inch piece of the printed circuit layout can be pulled off.
• De-solder the jumper, and replace it with a resistor that will calibrate the temp gauge. (we will figure out the resistors value next.)
• Take the end of the wire that is to be soldered and solder it into the solder joint that you cut the piece of layout out, and pulled the jumper out.
• Take a 5K. Ohm rheostat and hook it between the new wires coming from the dash, and the gauge cluster, with the 200 ohms resistor hooked into terminals “A”, and “C” of the sensor plug turn the ignition on, and turn the rheostat till the gauge reads what it did the first time you read the gauge with the 200 ohm resistor in the sensor plug.
• Read the resistance of the rheostat and that is the value of resistor to solder in the place of the jumper you took out earlier.
• Putt ever thing back together and test.
• Auto tap, or some type of scan tool would verify the accuracy of the temp gauge after the mod.

Jpr5690

iTrader: (13)

and the pics

Jpr5690

iTrader: (13)

Ok Now Let Me Say I Didnt Follow Alot Of These Instructions Past using them to modify The Circuit Board

some things in his instructions did not work (like the 3 wire sensor is too big for the opening in the cylnder head)

Jpr5690

iTrader: (13)

What I Did Different Was ....

1 Used A New Gm 2 Wire Coolant Temp Sensor (autozone)
1 Used A Harness For That Sensor (autozone)

Then I When To Lowes And Bought A 3 Way Piece Of 1\4 Threaded Female Brass Fitting And 2 Barbed Fittings To Screw Into The Holes And Plug Into Coolant Lines (pic Comming)

Finally I Screwed My Sensor Into The Top Plugged The Whole Assembly Inplace Of The Coolant Line That Flows From The Radiator To The Cylnder Heads


Also I Did Not Use Any Resistor To "calibrate" The Gauge Instead I Just Moved The Needle To Where It Should Read Once The Coolant Was Up To Temp And It Seems To Be Pretty Dam Close And Accurate So Why Bother...

Jpr5690

iTrader: (13)

here is a pic of the assmebled brass fittings and a pic of the line i spliced for the sender

Jpr5690

iTrader: (13)

also 1 end of the (2 wire) sender gets ran to a chasis ground while the other end just goes to the wire you soidered to the cluster's singnal input for the coolant temp

Jpr5690

iTrader: (13)

so to summerise

1: remove the resistor on the clusters circuit board that sends the signal to athe stock gauge

2: in its place soider a wire

3: run that wire thru the firewall to the engine bay

4: hook the new singal wire to a gm 2 wire temp sender ( bought at autozone and the harness can be found at autozone)

5:hook the other wire from the 2 wire sender to a chasis ground

6: screw the sender into a 3 way 1\4" brass fitting with a small extension on top and barbed fittings on each side

7: heat up the coolant and set the clusters needle to where it should read according the what the pcm is telling you (verify with hp tuners or autotap)

* the only side not here is the coolant line you spliced into is a molded piece with 2 different sized openings so when buying the barbbed fittings make sure to buy the right sizes .... i believe the line is 1\8 on the motor side and something a little bigger like 1\4 on the radiator side ..

** also it makes life easier just to reuse the molded line and cut it for the brass piece but if your line is old then go ahead and just pick up the two different sized hoses and snap em on

transam5.7lt1

iTrader: (18)

I plan on attacking this mod in my 99 ta, do you leave the stock sensor in place? Or do you leave everything as it is and just modify the cluster, run the two wires, ground and signal to hook to the 98 sensor and plug?

CULATR

iTrader: (96)

so is this the cure for the dummmy coolant gauge ??? or ????

JR HAWK 9

iTrader: (3)

jesus, I just bought a ScanGaugeII and I now have a digital temp gauge that is as accurate as the PCM and I didn't have to monkey around with that stuff

Jpr5690

iTrader: (13)

Leave All The Stock **** Alone Just Rewire The Cluster To Accept A Signal From Another Stock Sender And Slap That Baby In Where Ever You Think Is Best... Ground One Of The 2 Wires On The Sender And Soider The Other End Into The Cluster Signal On The Board (and Ovboiusly Disconnect The Pcm's Signal To The Cluster By Breaking The Circuit On The Board


Its Pretty Straightforward Mod The Hardpart Is Just Calibrating The Signal To Be Accurate And The Soidering On The Cluster Can Be A Little Touchy

TORCHD 02 TA

iTrader: (39)

way toooooo much work. Jsut get a water temp gauge and call it a day???

Jpr5690

iTrader: (13)

It Was Actually Pretty Easy, Easier Than Running Wires For A Redundant Gauge And Always Answering The Question "why Do You Have 2 Water Temp Gauges"

But Hey To Each Their Own...

lo_jack

iTrader: (27)

If you do not have the space for an extra temp gauge, this is great.

Does anyone know if all the fbody temp gauges can be 'fixed' like this?

Shame on GM for making the stocker lame to begin with.