Hello,
I'm having a problem with my water temp gauge. It keeps going up and down on the scale and "dinging" when it shows hot. I have changed the water pump, thermostat, fan clutch, flushed the system and 50/50 water antifreeze mix, changed the sensor but to no avail. It shows the engine is hot when it isn't. Is it possible for the digital gauge to be faulty? Has anyone else had this problem? Thanks
Yikes. Not sure on that one. It sounds like you have replaced everything that could be replaced, save for the instrument cluster itself. It would be possible to take the gauges module out of another V8 digital cluster and put it into yours since all three modules are separate. That way you could retain your mileage.
Out of curiousity, where did you find a new temperature sensor?
I found the water temp sensor actually at advanced auto parts. It is a two wire design instead of the traditional one wire that the mustangs and marks have. I took the car to an automotive electrical place and they said that the gauges generally don't fail, but it could be possible. It was totally fine until we did the 89 GT engine and mass air swap. Is it possible I could have an air bubble?
I don't think something like an air bubble would cause that kind of problem. You would think that it would eventually just work itself out if that were the case. Did you use your stock wiring harness when you swapped engines?
My guage failed, however it was reading low, not high. As Jkirchman said, which harness are you using? Also which sending unit are you using? If you're not using the Digital dash specific sender, it may be reading backwards......
To keep things simple I did go ahead and use the cougar 5.0 wiring harness and then of course the mustang mass air wiring. Interesting though, the cougar water temp wiring comes off of the driver fender and mustangs etc. have it on the engine harness. The cougar wiring harness DOES have a single wire connection to fit a single wire temp sensor, but it is not used. For fun I put a mustang water temp sensor in and used the other single wire connection, but the gauge had two bars on top and two on the bottom lit, so that didn't work.
I didn't think to specify about getting a sensor for the digital dash. That might be it, I'll check it out and keep you posted.
Well.....................I checked out the sensor and I have the right one. I was hoping the wrong sensor was the problem.:mad: Very frusturating. Would everyone agree that it is the gauge then? Does anyone sell just the module that fits in the back?
I don't think you will be able to find just the module. You will probably have to purchase an entire gauge cluster from eBay, a salvage yard, or someone on this board; disassemble it, and remove the left module with the tach and gauges. Then do the same thing to your cluster and swap the other one in.
You could just swap clusters but, as I said before, you can retain your mileage if you just swap modules instead. It's not that difficult to do, you just have to be careful because the parts are fragile. I've had my digital cluster apart a few times now without any problems. While you've got yours apart you can do the W2 mod to enable your speedometer to read up to 199 MPH if you want. Just solder a wire to join the contacts labeled W2 together. Here are instructions: http://www.foxthundercats.com/199speedomod/
I appreciate the help and advice everyone. I'll start looking around for a donor.
Did you find anything yet?
I had the same problem on my car, only it was the oil pressure gauge which read no pressure. I took it to several places and had the sensor changed and nothing worked. I ended up disconnecting the beeper thing from the dash because it got so annoying. I guess it could be the cluster (I have the digital one) I don't know. Eventually, I'm just going to run a separate buttstuffog oil pressure guage under the dash.
I haven't found anything quite yet. I called a couple salvage yards and if they had the right year it was the wrong dash....of course. Plus I haven't had the time either to really do any exploring. In the mean time I also just disconnected the sensor so it wouldn't constantly "ding".
where are you located in Kansas mechanized?
Hey,
I'm located in Wichita. The pic of your car looks familiar, did you go to the Ark City "Rod Run"?
Mechanized, were you able to fix the problem?
If not, I would check the resistance of the sender. At normal operating tempretaure, the resistance should be between 1770 and 4440 ohms (temp approximatly between 212 and 176 degrees). If it is less than 1770 ohms, and you know that the engine is not overheating, replace the sender. Use a Wells SU201. If the resistance is ok, I would check for an intermittent short in the red/white wire (do a wiggle test). If the sender you are using is old, it could be one of the faulty ones that had a bad crimp during manufacture. The sender is inexpensive, so changing it if it is old would not hurt and might fix your problem. Otherwise, it might be a fauly gauge module.
CaptHowdy178: Ground the wire at the pressure sender end to the engine. If you have 2 bars at the top and bottom of the oil pressure display and the can is blinking, grab a Wells PS4 Oil Pressure Sender. This should fix your problem. If the gauge still shows no pressure when the wire is grounded to the engine, or with the new sender, check the engine grounds and repair as needed. Also check for continuity from the sender terminal and the engine block. If the ground and continuity is good, and you still have no pressure reading form the gauge when the wire is grounded to the engine or connected to the sender, check continuity on the wire (wire end and pin 11A at the cluster). If the circuit is open, repair. If you have continuity, the gauge module is probably at fault.
Hope this helps!
I did my swap to 5.0 HO and now have this same problem on my full digital dash. Thinking it was a short on the wire, I unplugged the red/white wire on the back of the instrument panel and ran a jumper wire straight to the temp sensor and no change. The gauge was working before the swap.
I'm thinking that the HO coolant temp sender works on different terms than the SO. Am I right?
If you remove the single wire conn but dont ground it ,, then turn on the key, you should have one bar lit. If not,, you might wanna measure the resistance between pins 10a and 13a with the temp wire unhooked.
if its higher than 10k then the multiguage has a fault
if its lower,,, find your short
Your problem is odd but it may be a simple fix.
Tach/Multi guage diagnostic
all codes are Hexadecimal format and can range from 00 to FF (binary 0000 to 11111111)or (decimal 0 - 128) :grinno: . While active in the various modes, they can be used as a "wiggle test" to check for shorts and intermittant circuits. Anyway,, display will be in hex format.
hold the guages button in and turn the ign key to RUN
Advance through the tests by pressing the guages button.
A steady Tone and 8 bars lit is a passing test
No tone with 24 bars lit is a fail
To enter the Fuel computer self test
Press and hold the Select button atleast 5 or so seconds until the test display appears then advance thru the tests by pressing on Select over again.
That's exactly what I look at everyday....because I disconnected it at the sender; and I'm always wondering what my engine temp is. When I do hook it up, the bars light up from bottom to the top and then I end up with two lit bars at the top and the two lit bars at the bottom.