The Stovebolt Site Forums The Shop Area The Electrical Bay Question about oil temp line and temp gauge

I'm changing the fuel gauge on my 49 chevy. I'm stumped about how to remove the line for the oil pressure and the temp gauge on the gauge cluster. I'm afraid I'll break something. Does someone have advice for removing those two lines?

If I remember correctly, My 39's temp gauge was not removable at the dash. I don't remember what the oil pressure line was like.

The temp gauge has a sealed capillary tube that can't be removed from the dash gauge. The thermal sensing bulb must be removed from the cylinder head and carefully snaked through the firewall Then the gauge can be removed from the dash cluster. You can roll the tube into a loose coil for storage if necessary, but don't put any sharp kinks into it. The oil pressure line can be unscrewed at both ends.
Jerry

Thanks. I figured it out. My fuel gauge was burnt up. That's why it wouldn't work. Now I have a new sending unit and fuel gauge. Got it put back together last night and turned the key and the fuel gauge works. Woo-hoo! Now if I can just get the gauge pod back in the dash. I'm having difficulty because there is not enough room for me to get down there with two hand, one to hold the gauge pod in place and the other to start a nut.

I've lost two of the nuts that holds the gauge pod in the dash. Anyone happen to know the specs on those nuts and can I pick up spares at Home Depot or somewhere like that?

Pretty sure they're 10-32 size. I dug out a 10-24 nut to try and it started and bound up immediately, so the threads are finer at 10-32. Actually, I dug out 3 to try. My cab is sitting nose up on my rotisserie and the other two are now rattling around in the dash. I'll retrieve them later after I try and figure out what's causing the rattles as I spin the cab.

If you're doing much work under the dash, take the seat out. It gives you a lot more room to work, and when you get tired, you can take a quick nap!
Jerry

And do yourself a favor and replace the nuts with brass knurled ones form the hardware store. Much easier to install!

Lol. I have the seat out, but the lower frame is still in and it doesn't give me much room. The problem I'm having is trying to keep the gauge pod pushed in on the studs while trying to start a nut. If I don't keep pressure on the back of the gauge pod, it wants to fall out the back and I can't seem to do it with one hand. I had these out before when I rewired the truck and I don't remember having this much trouble. I'll figure it out somehow. I'm just ecstatic that the fuel gauge is now working.

The suction cup from a Garmin GPS windshield mount applied to the glass gauge cluster lens will give you a handle to hang onto from out front while you're starting the nuts onto the studs.
Jerry

Piece of plywood about 18” wide and 6’ long and a couple of jack stands will give you a nice platform to lay on while you work.🛠

Jerry, you are a genius. I just happened to have one of those suction cups on a Garmin. It did the trick. I was able to get the gauge pod back in and bolted up. Now, I need help with a couple of more things that happened during this fix.

1. When I took the temperature bulb out of the head, I noticed what looked like a small rubber seal that disintegrated. I put the bulb back in without it and naturally, I have a leak now. What can I use to fix that?

2. My ammeter has never really worked well. Before this fix, it would just barely be above the center line toward charge. It would go to the below center line towards discharge when I turned the headlights on. Now, it doesn't move at all. It's just slightly below center of line towards discharge and it doesn't move at all no matter what I turn on. I tried switching the wires on the post. I thought I might have put them back on backwards by mistake, but there's not change. I checked the charging system with a voltmeter and the alternator is working. Not sure what else to do about it.

Thanks,
Darrell

For hard to start nuts or ones in a cramped position we use the extra long "rod coupling nuts" and counter bore them for the first couple threads. Many lug nuts are this way where the nut slips onto the stud and can't be cross threaded. Amazon has 10-32 hex coupling nuts and I'd try counter boring with a #7 drill. Be sure to run a 10-32 bolt in and out of the bored nut to make sure there are no burrs. With the nut ready then you CAN'T do anything but start it if you get it over the end of the stud.

I recently had a major fit trying to get my gauge cluster and speedometer installed.
After many hours of tweaking and cussing. I finally got them in. I knew that the gauges came from this truck originally, but I forgot that I had replaced the entire dash with an aftermarket one 15 years ago. Those aftermarket guys can't seem to get anything right.

That seal around the temp sensor can probably be replaced with a thick rubber O ring sized to be a snug slip fit over the temp sensing bulb as you insert it into the cylinder head. A piece of rubber fuel line tubing cut into a thin washer might also work, giving you the equivalent of a square-shouldered O ring. If your ammeter isn't indicating either charge or discharge, it might have failed internally. Are you using an original equipment generator, or do you have an alternator on the engine? If there is a wire from an alternator straight to the battery or the connector at the starter, the ammeter won't move at all- - - -it's being bypassed. There is a way to put a shunt across the back of an ammeter to avoid pegging the needle right after startup when the surge from the alternator exceeds full scale on the ammeter.
Jerry

Jerry,

It has an alternator. The truck has been converted over to a 12 volt system. The wiring diagram that I have from the wiring harness I installed a couple of years ago has the heavy red wire coming from the ignition/battery terminal going to one post on the ammeter. The other post has two wires: one is a black wire from the starter and the other is an orange wire going to the fuse block. I tried swapping the wires on the post, thinking it was a directional issue and neither way seems to matter.

It sounds like the sensing coil of the ammeter has given up. Only a small fraction of the current passes through the needle circuit- - - -most of it bypasses the needle through a shunt. I like to add a second shunt made from a piece of stainless steel hose clamp material shaped like an "Ohms" symbol in a wiring diagram to keep the ammeter from pegging out right after startup. It's quick, simple to make, and adds a little protection to the fragile needle-deflecting circuit. Use the solid part of the clamp, not the area where the worm gear engages it. You probably need a new ammeter now, though.

For the ammeter to work properly, all the wires except the one from the starter should attach to one post of the meter, including the one from the alternator, and the fuse block. That allows the meter needle to deflect in the (-) direction when the engine is not running and the headlights are turned on, for instance, and indicate a charge when the engine is running. Good luck!
Jerry

Thanks Jerry. I went back out and looked at the wiring. The wiring diagram that came with the wiring kit showed the black 10 gauge wire from the starter and the red 14 gauge wire to the fuse block going to the same terminal with the 10 gauge red wire from battery source going to the other. That's how I had it wired up and apparently that was wrong. I moved the wires so the black 10 gauge wire from the starter would be by itself on the driver's side post and the red 10 gauge from battery source and 14 gauge red wire to fuse block on the same passenger side post. Now the meter registers just below the center mark, but it does go in the direction of negative slightly when the headlights are turned on. I guess I'm ok with it. I certainly don't want to pull that pod again and go through replacing gauges. Thanks for the help.

Your 71 year old gauge still works, but may not still have the original calibration. If it does function as you say, it is workable in my opinion.
As time goes by, pay attention to what the readings on the dial tell you. There should be consistencies under the various conditions of charge. After you get a feel for where it reads as compared to where it should read, you can then calibrate your brain to make your gauge usable.

Thanks Carl. That makes sense.

I just re-read my response and must say that you can move to the head of the class for being able follow that clumsy diatribe. I new what I wanted say, but I sure did write it clumsily.
Carl

You only lost two! I've even got my steering wheel out and it's still not fun. Oh to be young again and limber! The problem I had when putting my gauges back in is the issue of wearing bifocals...how in the world are you suppose to be able to do the bobble head move every time you're working in tight places? (and still can't see). The worst is having to use a flat screwdriver...now where is that slot? I guess being a geezer is better than not being one although I sure thought getting old would take longer.