temp sending unit
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
temp sending unit
My temp guage in my '79 always reads low. I want to install a new temp sending unit into the block. I see them for sale at specialty Corvette on line vendors from $20 to $49. My local Advance Auto Parts has one for the '79 Vette with single contact for $9.99. Do I really need to spend more than $9.99? Shouldn't it work o.k.?
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
My temp guage in my '79 always reads low. I want to install a new temp sending unit into the block. I see them for sale at specialty Corvette on line vendors from $20 to $49. My local Advance Auto Parts has one for the '79 Vette with single contact for $9.99. Do I really need to spend more than $9.99? Shouldn't it work o.k.?
First off how do you know there is a problem? Have you checked the engine temp against the gauge reading?
Usually the only reason to replace the sender is to fix a jumpy or failing needle.
Is the sender in there now an original or one you have changed recently?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
You could have a thermostat that is stuck "open"..... Does is take longer than 'normal' for the engine to get warm? When senders go bad they usually cause the gauge to read 'full scale' [one direction of the other]. Many places sell generic sending units. I suggest you get one from www.lectriclimited.com; they have exact replacements.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
Thanks for the info guys. I might be jumping to conclusions here about the sending unit. As stated maybe the temp is in fact actually low. I read a post a while back about resistance readings for the sender as it warms up but I can't find it again.
The car is still original with 45,000 miles so the thermostat, sender and guage are orig. After 30 years maybe it's time to change the thermostat.
I'll note the warm up time next time I drive the car and bring a pot of boiling water out to the car. I'll drop the sender into the pot of water and see what the guage reads. I sure wish I could find those resistance readings.
The car is still original with 45,000 miles so the thermostat, sender and guage are orig. After 30 years maybe it's time to change the thermostat.
I'll note the warm up time next time I drive the car and bring a pot of boiling water out to the car. I'll drop the sender into the pot of water and see what the guage reads. I sure wish I could find those resistance readings.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Better yet, just warm up the car with the radiator cap OFF and stick a thermometer in it to check the temp [and compare it to the gauge reading]. If you remove the sender, you'll lose a bunch of coolant. A quick temp check is a lot easier. [If you don't have one, pick up a little cooking thermometer at the dollar store.]
