I recently bought a 1970 Mustang Fastback - 351 Cleveland 2V - temp guage wasn't working - replaced sender unit - it worked but temp reading appeared too high - 3/4 up the guage at operating temp. Had radiator & engine flushed - very little dirt etc, couple of small leaks fixed, new 180 degree thermostat (suited to Clevelands) installed, new coolant. Guage still read the same. Replaced sender unit again with one suited to Mustang guage - guage now reads past H. At operating temp coolant is 182 degrees, coolant doesn't flow out radiator when cap is off, doesn't bubble at fast idle, combustion test okay, can put hand around top hose, water pump OK, no oil in radiator, no water in oil,no significant loss of coolant, belt tension ok, engine runs smoothly. Can only assume a guage problem. Spoke to auto electrician who said he needs to know ohms resistance readings for guage. For sender unit it is 220 degrees 18.49 to 15.75 ohm, 100 = 150 to 100 ohms.
i would say to make sure all the wiring and stuff is all set, and then if that is not the problem i would take it to a professional because it seems that you hvae done all you could do at the moment
First, get yourself a cheap aftermarket temp guage from Autobarn so you can safely drive the car !
As for the ohm's of the stock guage, hopefully someone here can help out coz I don't have a clue.
Next and most importantly, if you are going to own a Mustang in Australia, join the club.... they are there to help people out ! www.mustang.org.au/vic
Let us know how you get on
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1995 Mustang GT - Vert
RHD Conversion, Vortech V2-SQ, 42# injectors, CAPA Chip, 18" BonSpeed Wheels, 3.73 Motive Gears, AutoMeter Gauge Pod, Pedders Springs, Koni Shocks, 13" Cobra Brakes, BBK Shorty Headers
~~ He Who Dies With The Most Toys Wins. But Is Nonetheless Dead ! ~~
Oz Pony offers some good advice .
If your temp is really ok you can insert a resistor between the sender and the gauge they only cost a few cents each(Dick Smith or Jaycar) so buy a few diferent ones 2,5,10,20,50 and see which one or combination will get your gauge to read where you want it.I use a 10 ohm on my 66 hope this helps.
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Wimblton white 66 coupe C code 289 auto
97 Jeep Wrangler 4.0 auto, lift ,winch,33's etc
04 Holden VY SS 5.7 auto (wifes)
88 KLR 250
DISCLAMER:
Please feel free to ignor all advice/information offered
I could be wrong...... I have been before.
Thanks for your advice. Will try this out. Do you think it may be something like the constant voltage regulator to the instrument panel- I have ordered a replacement to suit.
Originally posted by RobertsMustang Do you think it may be something like the constant voltage regulator to the instrument panel- I have ordered a replacement to suit.
It may be the voltage regulator. I'm sure you can check them with a multi-meter. Save you buying one if its ok.
Does anyone know the volt range to check the regulator
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1995 Mustang GT - Vert
RHD Conversion, Vortech V2-SQ, 42# injectors, CAPA Chip, 18" BonSpeed Wheels, 3.73 Motive Gears, AutoMeter Gauge Pod, Pedders Springs, Koni Shocks, 13" Cobra Brakes, BBK Shorty Headers
~~ He Who Dies With The Most Toys Wins. But Is Nonetheless Dead ! ~~
Originally posted by RobertsMustang Thanks OZ Pony - I love doing this reseach thing for my Mustang
Researching problems is half the fun of owning a Mustang !
For your technical issues, feel free to use the Classic Tech Forum where the US and Canadian boys will help you out. They often have a wider knowledge. We tend to only use the Aussie Forum here for things we just want to say to the Australian members or if you want to know where to get a part locally etc.
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1995 Mustang GT - Vert
RHD Conversion, Vortech V2-SQ, 42# injectors, CAPA Chip, 18" BonSpeed Wheels, 3.73 Motive Gears, AutoMeter Gauge Pod, Pedders Springs, Koni Shocks, 13" Cobra Brakes, BBK Shorty Headers
~~ He Who Dies With The Most Toys Wins. But Is Nonetheless Dead ! ~~
Temperature guage problem 1970 Mustang Fastback 
