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Quick question for other 1970 owners...

When you switch the ignition on but don’t crank the engine, do all of your dash panel warning lights come on?

The reason I ask is that on mine only the oil, gen, and brake light come on. The temp light does not light up.

Thanks
 

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On my car only gen and oil come on, my brake light doesn't come on because she's not hooked up. I don't have a temp light that comes on either. :no:
 

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The '70 4-door:

'Oil' and 'Gen'* are on with the key in 'Run'.
'Brake' also shows, if it's set.

'Temp' only comes on while cranking the starter, unless the engine is overheating (I hope to never see that one...). However, I do not recall if that's the way they were wired from the factory. I did a little bit of reconfiguring with my ignition switch and the dash harness, including changing the way the warning light test circuit was wired (using existing dash harness ground wires and the G [ground] pins in the ignition switch).

*(Wired properly with an 12SI internal regulator alternator.)
 

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'Temp' only comes on while cranking the starter, unless the engine is overheating (I hope to never see that one...). However, I do not recall if that's the way they were wired from the factory.
Yes, that is the way they were wired from the factory.


The "oil" and "gen" lights will inherently light with the key on, engine off because that creates a situation where power is applied to the circuit (key on) but there is no oil pressure and the alternator isn't functioning (because the engine is off).

However, the key on, engine off situation doesn't do anything to cause the "temp" light to illuminate. So it has an added "bulb check" feature wired into the ignition switch. A set of grounding contacts in the ignition switch temporarily complete the circuit to ground (to light the "temp" light) when the switch is in the "start" position. This allows the driver to see that the bulb is good because otherwise it should only come on if the engine is overheating ... yeah, definitely not something you want to see. And a burned out / malfunctioning "temp" light combined with an overheating engine would be even worse!

The "brake" light also has a "bulb check" circuit connected to the ignition switch. So it too should come on when cranking the engine. Otherwise, it should only come on if the parking brake is set or if there is a failure in the braking system that results in a pressure loss to either the front or rear brakes.
 
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