CJ Temp & Fuel Gauge Fix

[Mickb]

Good job well done you should start selling them

[Dom]

Originally Posted by Mickb

Good job well done you should start selling them

Thanks Mick for the kind comment - I would happily have done, but I've got a family, full time job and three Jeeps all needing attention. After that, there's a garden full of weeds, peeling house paint etc....Zero spare time.

I'd be ripping people off. No-one would want to pay $80 for something like this. Yet that's $40 parts plus 2 hours @ $20/hour, a pretty ordinary hourly rate for a sunny Saturday arvo when you could be playing with the kids or fixing your own Jeep.

You know how it is - it's just not worth it.

Thought I'd post it so that anyone who needs it can benefit from me figuring it out and help themselves, although of course I'll happily answer any questions along the way....

[Mickb]

No worries man i know what you mean

[GMEMUD]

On this subject, sort of,To tidy things up a bit I bought a new set of gauges including the speedo, temp and fuel cause my temp one was spasmodic only to find out the CROWN speedo was all over the place, so inaccurate is not funny, the odo either read in miles or it just made up whatever it felt like but the temp and fuel is OK. I decided to have a look at the old one and clean it up and see what happens and the temp one was so full of fluff n stuff it is a wonder it worked at all so a bit of gentle air and soft brush and cleaned up the others as well as the faces and they come up like almost new. I also got a new oil gauge and voltameter while I was at it, both CROWN brand and neither of them worked. I pulled the voltameter appart and found that the way it was made with a big blob of plastic on the end of the hand it would not have moved with 100 volts into it, I completly buggered it trying to fix it lol, the oil I could not get to work properly with the sender unit they sent with it or with any other sender I had around the place so it ended up in the bin also. I bought them from the US cheap and that is what I got. Live and learn. But I thought CROWN was supposed to be a good reproduction brand.

[Dom]

I know exactly what you mean - hence the preference for keeping the original bits working. Regarding the speedo head itself, I was looking at buying one of those so thanks for the tip. There used to be a mob here in Melb that would overhaul and recalibrate mechanical speedos by remagnetising the rotor in the head - I'll see if I can find them...

Also, in getting the second set of CJ gauges working I found that the 6.2V setting I used on the CJ7 was a bit too high for the gauges to be accurate in the CJ8. In the CJ8, with 6.2V the fuel gauge is reading 3/5 with a bit less than 20L in the tank. Something closer to 5V would be right. I haven't sorted it all out yet but I'll put up a list of resistor combinations to get various output voltages so that anyone can adjust the regulator to get the gauges reading spot-on.

[Tote]

Thanks very much to the OP on this one, I built one of these for our CJ10 this afternoon. The design using the LM2575 is much better than the ones elsewhere on the net using 3 pin regulators. The LM2575 is a bit hard to come by but a LM2576 is the same except its rated at 3 amps rather than 1 amp.





Regards,
Tote

[Dom]

You’re most welcome - hadn’t given this one a thought in ages. Now have a 74 CJ-5 to restore so I’ll have to make another one myself! Good tip on the updated IC - cheers!