I got my temp gage to work . . .Loose wire

Great info. I just bought a 55 Ford with only one sending unit on the drivers side. Based on what I have been reading it sounds like some one put the wrong sensor in. The temp gage stays on hot. There is a spot under the distributor on the pass side but never used. If I have only one sensor and mine is wrong, what sensor do I need?

sqt0341,

Anything "could" be.  Part of the issue here is that it's very difficult for any of us to troubleshoot remotely and "blind".  All that I can do for the present is what's already been presented, for what information we have from you.  For good or bad, the actual hands-on trouble shooting is up to you.

As per the Manual test: have you tried (with key-off) to solidly "ground" the sensor wire to the engine block, then get into the car & momentarily turn-on the key to see if the TEMP gauge goes to below "cold".

Do this only long enough for it to get just to below "Cold", then turn the key back-off right away; otherwise, you WILL burn-out the gauge!

If it does go to below "cold", the gauge and wiring is probably O. K., per the maintenance manual.  If not, you either have a wiring issue, or a bad gauge.

Then, try a matched "sender", instead of the switch; and, let us know what the results are.  We may then be able to help better based on results.

Many of us will be more than happy to guide you along, as long as you provide specific questions dependent on what you "find".

Regards,   JLB

55 Ford Crown Victoria Steel Top

Hey, thanks for the help. I think I understand now. Theoretically, I think I've figured it out. I have a new temp sender on order, so we'll see if I do understand realistically when it gets here. I guess the only thing that's bothering me is that, as I previously mentioned, there appears to be a thermal switch where the temp sender should be. Given that the thermal switch should only activate when the coolant temp reaches 217 (or boiling), why is it showing hot now? I know there's coolant in it, I know the coolant is good, and I know that it's circulating. Could it just be that the switch is plugged in to the loom at the wrong place that's causing that?

Eric

'55 Fairlane Club Sedan

sqt0341,

Take a look at the other two threads very close-by regarding fuel and temp guages - they may help your understanding.

If I understand correctly, some of the early production '55's had both the temp sender in the 5, 6, 7, 8 cyl head, and the overheat switch in the 1, 2, 3, 4 head; this switch would go "open" upon being too hot, and send the TEMP guage soaring over "hot" in order to get the driver to pay attention; the sender was "in series" sith the switch to "ground", as I understand the original setup.

Ford (apparently) dedided that the switch was an unnecessary production expense, and eliminated it fairly early-on in the '55 production year.

Regards,   JLB

55 Ford Crown Victoria Steel Top

Well, that helps in some ways, but not so much in others. The wire leading to that bulb appears to be tied into the temp sending unit wire. I am fairly certain on this as there is resistance from the lead into the temp sender (which looks like its actually a thermal switch) to the lead into the oil pressure switch. I'm no electrical guy, but that tells me they're tied together. Does that sound right?

Eric

'55 Fairlane Club Sedan

The switch at lower part of block is oil pressure switch!

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Sorry to drag this one out of the inactive files, but I have a question regarding this stuff. I just bought a '55 Fairlane 272 (first classic, so I'm a babe in the woods) and the temp gauge starts out cold at start-up, then proceeds to scalding pretty quickly. I have read the previous posts and see that the '55 272 should have one temp sending unit on the driver's side (left) head, back toward the firewall. I have found that unit, but it would appear that a previous owner had put a thermal switch in its place (instead of the flat-head screw post that should be on the sending unit, there is a single plug type post, which I am gathering makes it a thermal switch). I am also gathering from the previous posts that there really is no need for a thermal switch on this engine...is that correct?



I have also found that there is a single wire leading from the head, where the thermal switch is apparently incorrectly located, to the bottom of the driver's side of the block where there is a temp sending unit that is also apparently misplaced. Is this where the thermal switch is supposed to be located? Or is this just a bad placement altogether?



If it is, it is my plan to disconnect the wire from the misplaced sending unit (toward the bottom of the block) and leave it in place as it is acting as a perfectly good plug the way is it and, if I don't do anything to it, I probably won't break it. Then, replace the misplaced thermal switch (in the driver's side head) with a new temp sending unit. I will need to swap the current spade connector that is linking the gauge wire to the thermal switch with a connector that will work with the sending unit, and will probably just cut off the connector that is currently attached to the misplace sending unit (at the bottom) and tape it off (leaving it there).



Does this make sense? I'd like to be able to answer who would have done it that way to begin with, but I can't. Thanks for taking the time to read this.

Eric

'55 Fairlane Club Sedan

Well Redline, all these other fellas say me and the Manual and whoever sold you your parts are wrong so I guess I will go with that... Sorry if I misinformed you.

BOB

Bob:

The shop manual is indeed wrong in this case. Only 1 sender in the driver's side head. That isn't the only error in the 55 manual, by the way.

BrodieSavannah, GA