Temperature gauge problems

JasonNC

I have two separate temperature gauge problems. My 48 Commodore overheated while in a parade and the gauge is now stuck on hot. Which is mostly likely to be damaged, the sender or the gauge? On the Kaiser, I put in a 307 Chevy engine and the gauge only works when I ground a test light and stick the point in the wire leading from the temp sender to the gauge. Otherwise, the gauge will not move. The temp sender on the Chevy engine is new and the gauge (which worked with the original engine even after being converted 12 volts) will move all the way to Hot when the wire from the sender is grounded to the engine. Does it need some type of reducer or diode? The reason I ask is because the test light flicks on and off when I use it in the manner described above.

Unknown

maybe not a solution, but did you change polarity when you changed engines? That could cause a problem. When you ground a gauge with pos grd and it goes to hot it indicates the gauge is OK {useing the wire that went to the sender }

Unknown

Takie wire off sending unit and short it to the block and see what happens. Could be a bad sending unit or gauge voltage regulator.

JasonNC

I changed the polarity when I changed engines. When I take the wire off the sending unit and ground it to the block, it goes all the way to the Hot end of the gauge, which it is supposed to do. The sender does not work with the engine running unless I use the test light as I described in the original post. Am I to assume that the sender is bad? The guy at NAPA assured me that this was the sender I needed since the original sender was for an idiot light instead of a gauge.

Unknown

The 48 temp gauge remaining in the HOT position after the overheat is most likely the gauge unit. to check the circuit remove the wire from the sender, turn on the ignition switch and check the action of the gauge. if it remains in the hot position it is a bad gauge unit. if it swings to the cold position with the sender wire removed and goes to hot when the wire is reconnected with the key on, it is a shorted sender.

As for the gauge not working in the Kaiser with Chevy 307 under the hood - The problem is non-compatibility between the GM sender (resistance value) and the Kaiser gauge unit.

Unknown

FRED is pretty much right here, not be argumentive but I went thru this and was told by the parts house senders are not even voltage sensitive, it's a small amt of amps they are sending and did indeed find that a unit from a 12v car would work in my 6v system and is accurate. Not for sure but I would guess changeing polarity is the problem. If the gauge is self grounding { has only one wire } try removeing it from the dash and reverse the current flow, that is take the wire to the chassis and a wire from the gauge unit houseing to your sending unit.Try it cold and engine warmed. If that makes it work you can use thin plastic between it and the dash, drill the mount holes out to put in nylon spacers easy to make from washer around the screw and a nylon washer to insulate it. To check the sender it should show no ohms cold and increaseingly higher ohms as it warms, you can heat it in a can of water.

[Deleted User]

Jason, When You Swapped the engine in the Kaiser did you run a ground strap from the engine block? Since the Kaiser is a body on frame, it needs a grounding strap from the engine to the body GM ran a braided strap from the engine to the firewall. I left it off after an engine rebuild in a 62 Impala and like to have never figured it out. It can cause problems with gauges, charging, lights, things that you would never consider. May not be your problem but is something to consider.
Bob
Are you going to make Pigeon Forge this year?

JasonNC

I eventually got around to running a ground strap from the engine to the firewall. It didn't change anything. I will check the gauge on the Hudson as Fred recommended and try using the plastic spacers on the Kaiser. Based on what I've seen so far, that solution has potential. As far as Pigeon Forge is concerned, I have really made up my mind yet. I need to talk it over with the wife. It depends on how well either of the old cars are running at the time. Going to a Hudson meet in a Chevy pickup just isn't the same....

junkcarfann

If all else fails, you could use plumbing adaptors to fit the Kaiser sending unit to the Chevy engine.

Unknown

On the Chev / Kaiser deal bear in mind voltage to the GAUGE if you haven't allready done so. Use what it originally had. It is differant than sending unit not being voltage sensitive. And remember the mounting SCREWS have to be isolated going thru the hole.

JasonNC

Okay, I put the temp sender from the old Kaiser motor on the Chevy engine and the gauge now works. I grounded the wire to the temp sender on the Hudson and it went all the way across the gauge which I'm told means that the gauge is still working and the temp sender is bad. I called Dave Kostanek and he doesn't have the temp sender for a 48 six cylinder. He gave me Frank Dluhy?!?'s number. In case that doesn't pan out, any suggestions?

Unknown

Glad you got one working. Tech tip for future use , If I read it right, then the dash gauge is not polarity sensitive? good to know for future use.How about the voltage?

mars55

Does anyone know what size thread the '48 uses?

JasonNC

37 Terraplane#2 wrote:

Glad you got one working. Tech tip for future use , If I read it right, then the dash gauge is not polarity sensitive? good to know for future use.How about the voltage?

All I did was switch the wire around so that when you grounded the wire from the sender to the negative post on the battery or the frame, the gauge would move to the top. It was the opposite before I put the Chevy motor in. It's funny. I switched to12 volts sometime back with the original engine and the gauge still worked as is. I think I tried to put a voltage reducer on both the temp and fuel gauges and only the fuel would work. When I disconnected the voltage reducer from the temp gauge, it started working. The car originally had a voltage regulator/reducer of sorts for the gauges anyway. Thanks for the congratulations.

mars55

JasonNC wrote:

I called Dave Kostanek and he doesn't have the temp sender for a 48 six cylinder. He gave me Frank Dluhy?!?'s number. In case that doesn't pan out, any suggestions?

Well, if the thread is 3/8 pipe, a NAPA TS6153 or Standard Motor Products TS24 will work. This sender is used on the '65-'73 Mustang and other Ford products of the late sixties and early seventies.

Unknown

Also keep in mind that the Hudson and the Kaiser both have constant voltage regulators feedin the guages, King Seely guages used them, the purpose is to supply the guages with 5 volts. If all else fails try using one from a 56 or later Ford product.