rangepony69

I looked at several videos on-line for testing gauges but they don't exactly work for my application.....I have a 69 350/350 convertible. It has been disassembled for several years and I'm trying to get it together. Dash is out of car and disconnected. I need to know which gauges I need to purchase/repair.....all the faces look excellent ......green on black.

Fuel gauge: needle tight and if I move it it with my finger it will stay where I put it. I thought they should "float" and bounce back toward empty when disconnected.

Water temp: needle tight and will slowly "float" back to center position around 210 when moved

Clock: I hooked it up 12 v power to tab and grounded case....nothing

Oil pressure: spring loaded toward 0 (probably OK)

Battery: nice "wiggle" toward center (probably OK)

Thanks for any links or help!

MelWff

this link is for testing a fuel gauge http://repairs.willcoxcorvette.com/1...el-gauge-test/
this link is for the water temp http://repairs.willcoxcorvette.com/c...gauge-testing/
clock you already know it's not working
this link is for the oil pressure http://repairs.willcoxcorvette.com/o...ing-1974-1982/
this is for the ammeter https://www.corvetteforum.com/forums...procedure.html

0Willcox Corvette

I emailed you back today... stop worrying about where the gauges are when they don't have power. Power them up with out ohms input and follow the instructions on the site. Then ground them out and see if they work as described.

A gauge without any ohms input will go to the best of the world... A fuel gauge will go past full, a temp gauge will go to cool... Then when you ground out the ohms stud they'll go opposite.. Empty and Hot...



Willcox

rangepony69

If I power everything up on the bench is everything 12volts? I like to use a battery charger when I'm testing things but do I need to reduce voltage?

san

Be carefull using a battery charger....although they put out 12v DC, they also put out a high amount of AC....and some even pulse the DC current in various voltages, which can do harm....needles spiking hard, bouncing around at anywhere from 10hz to 100 hz....not really ideal for checking. There are some chargers, like trickle chargers, that just put out a clean 13.8v DC. You want a clean dc current to test with.

7T1vette

A battery charger puts out 'chopped' DC voltage. It is meant to be used with a battery...and the battery stabilizes the voltage. The charger alone may do more damage than good; and it could send out several amps to some low-current meters (if not wired properly or defective gauge). Not a good idea.

NRAROX

Clock. Here is a piece on clock repair. You will likely find that the contacts do not align. They NEVER did. Use a diamond file to clean them. Not Emory or sand paper.

http://pcfred.com/Vettetip/FixC3Clock.htm

rangepony69

Thanks.....I've done alot of clocks on other cars, I just have to figure out how to crack into the case.....

rangepony69

Sounds like everything is 12v.....I guess I could use a battery.....any leads on where and what size pot to buy?

san

Not sure what you mean by pot...i trim pot? Like a variable resistor? I would use an analog house lights dimmer....not sure if it would work but at least it could handle power from a car battery. In order to select the correct trim pot you would need to know the wattage of the devices you would be testing...a local electronics hobby shop should habe them up to 1 watt fairly cheap...which should suffice...but im not sure. Each sending unit that sends its signals to the gauges is usually from 1k to 10k i believe so a 1 watt, 10k pot may work just for a quick test.

0Willcox Corvette

Your not running the voltage through the pot (potentiometer) (unless your using it on a 63-67 fuel gauge).... so pretty much anything with adjustable resistance will work fine. You can use a series of old flashers as long as you know the valve.

Use a 12 volt power supply, not a battery charger... or use a wire off the back of the alternator. Your just testing gauges so nothing bad will happen.

The fuel gauge is 0 ohms is empty, 90 ohms is full.
The temperature gauge expected inputs is shown in the picture below.

NRAROX

Clock: cracking into the case? Pliers turning three bent prongs. I think it was designed to be opened about twice, despite the one year service schedule.

0Willcox Corvette

I loved that write up, it was awesome. If I remember correctly the only thing he didn't realize was that you can speed up the clock or slow it down by rotating it 12 hours forward or backwards. Forward speeds it up, backwards slows it down.

The faces are where you can run into issues when you build/repair the clocks. If the tangs break off you can epoxy them back on the clock when completed but I would test the movement (and the accuracy) before doing that.

Willcox

68sbShark

Can you elaborate on this? I gave my clock a once over using the above mentioned page as reference, and it now works....just does not keep accurate time.

Thanks,

Rich

0Willcox Corvette

On the old Borg movements (factory installed 1963-1981), if you turn the hands backwards 12 hours.. it will slow the clock down, if you turn them forward 12 hours it will speed it up... You do this with the adjustment stem .

Willcox

68sbShark

Huh....who knew....except for you obviously. This will be my winter project. Getting the clock to maintain proper time.

0Willcox Corvette

I'll call this OFS.. old fart syndrome.. Been building these junk movements for over 30 years. In the old days it was easier to rebuild the movements than to send them into Borg to have them fixed under warranty, it's just a poor design and one that fails more than it works. Some people have all the luck with the standard movement and they last for years, I know the one in my 70 and 72 is still going strong, but the odds are in the side of failure.

Ernie

7T1vette

That clock is self-correcting...IF you follow the right procedure for doing so.

Once you have the clock powered up, you set the correct time on it. You also note the actual time when you made that adjustment. Wait 24 hours [+/- a few minutes] and correct the clock's time by adjusting it in the "nearest" direction. (If it is 15 minutes 'slow', turn it CW; if it is 15 minutes 'fast', turn it CCW.)

Make this adjustment on consecutive days...only once per day at about the same time of day...and the clock will be on-time and accurate after no more than 3 days.

Note: The 'rate' of the self-correction depends on the adjustments being made once-daily at 24 hour increments.