Stephen L. Hanselman
Hi,
Remove the lead from the temprature sender (at the thermostat end) and look
at the guage. Now ground the wire and look at the guage. Do NOT tie the
wire to ground, have someone else in the drivers seat watch the guage while
you ground/un-ground the wire.
These guages work by applying a "ground" to the temp (and fuel) guage. The
circuit is esentially battery (+) -> voltage regulator(stabilizer behind
speedo) -> guages -> senders -> ground. The sender has a consists of a
resistance that is temprature sensitive. One side of the resistance is tied
to the chassis and the other goes back to the guage.
Another test method is to take a digital voltmeter and read the voltage at
the temprature sender. It will be fairly low.
I'd like to say I did this on my TR6 but it's stripped. I did verify this
on my Ford truck. grounding the lead caused the meter to go up (higher in
temp). The DVM reading was erratic, indicating between 125mV and 350mV.
This is probably due to the mechanical voltage regulator Ford uses.
This would be much easier than tearing the dashboard apart.
If I apply my normal troubleshooting skills, I'd say the sender or the wire
as it attaches through the crimp lug was damaged during the hose
replacement. Damage may not be visible.
Regards,
Stephen L. Hanselman
Manager, Defense Systems
Datagate Incorporated
+1.775.882.1313 x253 (voice)
+1.775.882.1689 (fax)
Stephen.Hanselman@datagateinc.com
TR6@kc4sw.com
I just installed new green radiator hoses on my 76 TR6 and suddenly my
temperature gauge seems to have stopped functioning, (doubt that it's just a
coincidence). The wire attached to the sensor (just below and to the
driver's side of the top hose and thermostat) is still firmly attached. All
of the wiring to the gauge itself looks good also.
Does anyone have an idea of what may have gone wrong? Chance are that I
knocked something loose when I was fighting with the hoses but I sure can't
find it....
Perplexed in Chicago???
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