More Temp Gauge Questions
Thread Starter
Burning Brakes
Joined: Nov 2006
Posts: 893
Likes: 7
From: Orange Park Florida
More Temp Gauge Questions
After reading the threads discussing sending units and gauge readings I think I have a problem. I purchased a BWD WT203 unit and installed it. Something wierd is happening.
Prior to this change-out;
I had a spade type sender from NAPA that was supposed to be functional for my car (72 w/350cu).
Once warmed up, the gauge would indicate 1/4 reading, then, if extremely hot would shoot up to 210-220 - then when cooled a little, would drop back to 1/4 reading. Around a 60 degree swing. When I shut the engine down, gauge would drop to zero.
After installing the BWD WT203;
Once warmed up, the temp gauge would read 190-200 range - what I would expect. When extremly hot (after a hard run) the gauge would jump to 230-240 range (too high), and once cooled some, fall back to the midrange. Now when I shut the engine down, the gauge stays at the current reading - it does not fall back to zero. If I lift off the sending unit wire there is no change. If I ground the sender wire, the gauge will shoot to the full hot range (off scale), then once ground is removed the gauge falls to zero.
All I have done is installed the newer sending unit. Is my gauge faulty? Could I be missing or have a faulty dash ground? Or does it sound like a defective sender? Any ideas?
Prior to this change-out;
I had a spade type sender from NAPA that was supposed to be functional for my car (72 w/350cu).
Once warmed up, the gauge would indicate 1/4 reading, then, if extremely hot would shoot up to 210-220 - then when cooled a little, would drop back to 1/4 reading. Around a 60 degree swing. When I shut the engine down, gauge would drop to zero.
After installing the BWD WT203;
Once warmed up, the temp gauge would read 190-200 range - what I would expect. When extremly hot (after a hard run) the gauge would jump to 230-240 range (too high), and once cooled some, fall back to the midrange. Now when I shut the engine down, the gauge stays at the current reading - it does not fall back to zero. If I lift off the sending unit wire there is no change. If I ground the sender wire, the gauge will shoot to the full hot range (off scale), then once ground is removed the gauge falls to zero.
All I have done is installed the newer sending unit. Is my gauge faulty? Could I be missing or have a faulty dash ground? Or does it sound like a defective sender? Any ideas?
Last edited by JimT; Aug 29, 2010 at 02:06 PM.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
It sounds normal now. All the gauges Ive seen don't return to cold, they freeze where they are when the key is turned off. Not sure why just a sender change would do this.
The NCRS PV manual says it should read with the key on but should go to cold with key off.
200 - 230 seems OK , A heat gun will help.
The NCRS PV manual says it should read with the key on but should go to cold with key off.
200 - 230 seems OK , A heat gun will help.
Thread Starter
Burning Brakes
Joined: Nov 2006
Posts: 893
Likes: 7
From: Orange Park Florida
Thanks for the responses. I'm going to a friends garage tomorrow and he has a temp gun. Also, my sending unit is mounted in the manifold adjacent to the thermostat housing. I'll verify temp readings and figure out what is going on.
Thanks again.
Thanks again.
