[roy]

hi i have a 1928 modal a tudor it has a289 windsor and c10 auto . i seem to have an electricall problem with the dakota digitall dash in particular the temperature gauge it is very eratic and will go from 75degc to 95 deg in a matter off seconds then drops back down again just as quick.i thought it might have been afaulty sender unit but no luck i allso have since ran another earth lead from the engine block to the chassis but still no good.

[docvette]

Doc here,


Before you start tearing into the electrical. are you sure your system is purged?

Does the temp gauge do regular "Excursions" up down , up down as you drive along? If so..it sounds like you have an air bubble trapped at the sender..be sure you burp the system of all air through a full recovery system..

A Sender cannot read air..as it gets pushed forth and back you get water, air , water air..and the gauge will respond the same way.

Try that First and if not post back and we can track down the electrical...

Is that a Dodge Dakota dash?

Doc

[roy]

thank you docc vett for your thoughts .i have tried to perge the system off air but dont seem to get anywhere .the cooling system is alittle complicated as the car runs on lp gas only no petrol. it is running twin converters on top off a weind tunnell ram looks real trick and runs hard .the dash is not from a dodge dakota .it is an american made hot rod dash after market .

[Canzus]

I think Doc is onto something, it the radiator fill
below the T-stat?? Do you have a overflow tank
installed? If not, there is a good chance you've
got an air bubble... Jack the front of the car way
up in the air, pop the radiator cap, and add some
more coolant...

[roy]

thanks for the input canzus the radiator filler is way above the thermostat and i do have an overflow tank

[Kevin45]

What degree of thermostat do you have in the block. By converting Celcius to Farenheit, I am showing a temp of 167 to 203. The 203 seems to be pretty much normal if you have a 195 degree thermostat. With that size of thermostat it is not uncommon to vary a little on either side of the given temperature. The 75C seems kind of low though. What type of radiator (how many cores) are you running and do you have electric fans. Also did the sending unit come with the Dakota Digital dash or is it a stock unit? And if it is a stock sending unit, did it come from a dealer or some aftermarket place?

Kevin

[docvette]

Doc here,

If you say it's free of air bubbles,
(fords are hard to purge..I Know a taxi fleet that installed brake bleeders in the water neck to purge off air...they used t overheat every time the system opened.)

Then, are your senders matched to your gauge? 0 to 90...all the way to 0 to 290 ohms...They must be matched to function accurately.

Doc

[roy]

roy here thanks for your thoughts .i run a 4 core radiator a180 degree thermostat and the biggest electric fan that i could fit .the sender unit was supplied by dakota as part off the dash package.
i dont know for certain that their is no air in the system but i have tried to purge it .