Packard Forum Index » Post-War (1946-54)

temp gauge will go to extreme hot position soon after starting. how do i check out temp sender? where is it located? more q's later TIA CC

Need more info on year for troubleshooting recommendations. As to location, straight 8 is screwed into side of head -- drivers side at rear just above starter motor. V8 is screwed into a bracket bolted into the extreme rear of head on the driver side and facing firewall.

If you have electric gauges, there are different units used with varying types of senders so operation depends on year. Typically most -- but not all -- would go to extreme hot side if wire or sender was shorted. Prior to 48 many were mechanical gauges.

SORRY 48 custom 356 cu in

The 22-23rd series should be electric with bimetal type sender. Those don't have a specific resistance range you can check like other senders do. Normally the gauge needle will rest on the hot side when off. When key is turned on the needle should start moving to the cold side and then slowly come back and stabilize approx midway as engine reaches normal temp. If this is what it is doing but then continues to go to hot side after running a while then I would guess an overheating problem.

Possible causes are numerous and covered in many threads here. A search will help find them or others can comment again on how to check for the various things. Clogged radiators and distribution tubes are at the top of the list along with timing, exhaust restrictions, stuck thermostats and other assorted things.

If the needle never moves to the cold side check for a broken or disconnected wire to the sender. If the wire looks OK then ground it at the sender and needle should start to move to the cold side. For testing purposes don't leave it connected to ground longer than it takes to verify needle moves properly. If it does move, sender is bad or does not have a good ground. If needle doesn't move at all when the wire is grounded, the wire or gauge is bad.