Hello all, I'm working on my 49 F1 12v neg ground.


I've rewired the truck and wanted to fire it up today so I could check my gauges before I get too far into it.


Was -40 today so a flexible pipe took out the exhaust for me.

I took an entire gauge cluster out of an F2 last year that was in great shape but have never tested the gauges until now. I'm running this gauge reducer that is meant for multiple gauges:

I am only running one wire from this reducer to the temp gauge and letting the metal bar connect it to the other 2 (fuel and oil). My fuel sender is not hooked up so I have no idea how that one is doing, but my oil sensor seems to be working fine. The problem lies in my temp sensor. With the key off it is pegged to hot, when I turn to on it starts to climb down. It gets to about 3/4 and then flings back to full hot and keeps trying to go to cold for a while. When it's running it will hang out there for a while, but then will land on the "H" until I turn the truck off and then it will peg out again on hot. I took a video but have not figured out how to post it. If someone knows, please let me know.

Here's some photos:
Truck/key NOT on:


Pegged to the hot side (is that normal?)


Key on:


Climbing towards 3/4 hot




Hangs out around here when running for a while (note: truck is not running for this photo)


I don't think it's the reducer since the oil is working (it's reading around 40 at idle), but I'm up for any advice. Thanks in advance!

 

The normal operation is Key Off = Full Hot, Key On = drive to Cold - then react to temp. Looks like you are either losing power or the sending unit is acting up

 

Thanks for the reply Ernie! I'll replace the sender and see what happens. It'll be a few weeks, but I'll update this when I get it figured out. Have a great day.

 

Well, your little CVR could be cutting out. Try connecting only the temp gauge to it (remove the oil press & fuel) to see if it changes behavior. I don't know what the amperage rating of your CVR is, but because they're pretty cheap, I always run one for each gauge.

 

Thanks Ernie. Is the CVR the reducer from 6v to 12v? This guy:


I know it stands for Cluster Voltage Regulator, but I don't know where mine would be. My power runs from the key to the reducer pictured above,and then right from the reducer to the temp gauge. The metal bar then gives power to the other 2 gauges. The other post on the temp gauge comes right from my sender as seen here:


I'm sure this isn't news to you, but I'm just trying to be clear so you know what I have. Thanks again!

 

So I decided to take off the wire from the sender and connect it to the ground to see if it would go past that 3/4 mark where it would get caught and fling back to full hot. When it was hooked to ground it did get caught up for a second at that same spot, but then it went to full cold. I then tried it several more times and had the same result except that it didn't hang up at all at the 3/4 mark. So, that sounds to me like it's the sender. My worry was that the gauge was messed up and wouldn't allow it to pass that point for some reason. Any other thoughts before I order a sender?

 

The manual has a very thorough test procedure

 

Do you have the Shop Manual? It's on pages 279 - 280.

 

Thanks for the reminder guys. I had a hard time understanding the manual, but it turns out I have some good news and bad news...... The good is that I remembered that I had a sender from the 8BA that I picked up this year with the F2. I put it in and the gauge seems to work as normal with the key on. I didn't start it up, but so far so good.
The bad news is that I wasted your time...... my bad. Thanks again to all you guys, you're what makes this site great! I hope you can enjoy your trucks this week.

 

No not a waste of time. My thoughts are this temp setup has always been a
problem especially going to 12vt neg. The oil and fuel usually always work
but the temp. is finicky. What I did was to use any 1973 to the early
1980's temp gauge and swap face plates, they will fit all 1948 thru 1956
gauge housings and use the sender for that application. Only difference is
that when the ign is off the needle rests at "cold instead of hot" and I don't
care about that. Then I found using one sender (instead of two) if one
bank runs hotter, the hot water will seek the one sender bank and balance
out. Note these King Seeleys fill fit oil fuel temp gauges you just have to
use the matching sender.

 

Thanks Big Job! I knew I read something like that somewhere, but never did find it again. It's good to know the exact years that I can use if needed. Once I get Old George on the road this spring I'll know better if the gauge is working normal while running/driving or not. I love your truck, by the way.