Temp gauge pegged

[Jeff W]

I can hardly wait!

[falcon cobra]

RS may not have a 7808 they are not used much, I can find out the resistor size for the lm 317..jh

[Luva65wagon]

Me as well. It seems such a simple solution too. I have enough cans I can make 5 of them right away!

[Luva65wagon]

Yeah, quick search shows 7808 not a Radio Shack stocked item. Can get lots on-line. LM317?

[falcon cobra]

I have a 6v I made for my cd player you can have or the TO3 8v can [ transistor type ] ..jh

[Luva65wagon]

I have 317's here and calculated R1 @ 240 ohms and R2 @ 1.3K ohms gives 8 volts out. At least I think so...

[falcon cobra]

wire it up and check voltage 7or8 is close enough, I'am out of 240s and only have 1ks so I gave up.. if you cans the case is v out so must be insulated from any ground, but you knew that...hope it works ok. we could put it in a box and charge like dearborn's theves wharehouse...jh

[Jeff W]

Technically couldn't you use a pot instead of a fixed resistor so you can "fine tune" the fuel level gauge to be accurate?

[falcon cobra]

Yes jeff, I use it with a 5k pot and have a varable voltage depending how much voltage you put into it up to 35 volts..jh

[Luva65wagon]

That's very true! You could fine tune the gauges until your hot engine reads cold and you could happily ignore it - like most people do with idiot light anyway.



Sadly I didn't get to the place yesterday I could do anything to fix this on the Comet before it left my possesion, but I am now armed with a plan and may experiment using a host of dashes and parts I have laying around. I'll either install into it later one of the originals coming to me from Dennis Carpenter, or perfect a solid-state replacement.

[pbrown]

That's very true! You could fine tune the gauges until your hot engine reads cold and you could happily ignore it - like most people do with idiot light anyway.

Just put a sticker over the gauge and draw in the correct temp with a Sharpie.

[BPVan]

Roger -

FWIW I bought a solid state regulator off of eBay to replace my "crude" regulator. I have been running it for over a year now and all of my gauges work great, never had one issue. They are a little more than $1 but that is made up by the time you save as it is plug and play.

[Luva65wagon]

Hey all.

For what it's worth I received 3 regulators I ordered from Dennis Carpenter. They were in the original style package and I mentioned to Gina before I put something into her car I wanted to test these 3 and see what they output.

I was a little surprised to notice they didn't have the little screw you could adjust things with. When I applied voltage to them they came up at a steady 5 volts instantly. No pulsing 0-10 volts. So I peeled one open to discover they are, in fact, solid state. The guts are potted in some black epoxy resin, so no telling exactly what they used, but there is no bi-metallic heater in there.

These were $20 a piece.

I'm going to throw one into the Ranchero tomorrow and see what kind of readings I get. The one in the Ranchero is working, so I assume my readings should be similar.

I do have some 7808 regulators coming from China ($3 on ebay) so I may build up one of those too and see what difference there is with these.

[falcon cobra]

That why they pot things so people won't steal there stuff, but why waste the epoxy for such a small thing like that...oh well..there is a place called digi key that sell lots of electronics in the usa, I havent got anything from them in years. sounds like 5 V will work..jh

[Luva65wagon]

Don't know why these are 5 volts when the guy on YouTube said the 7805 (5v) version didn't maintain 5 volts under load and he went to the 7808 in final version. That's what I bought off ebay, 7808.

Maybe this Carpenter version will hold up under load and maintain the 5 volts. We'll see tomorrow.