CatManDo

Yours was the only one from that batch that had gone out. You should have the replacement by now. Let us know how it goes.

2016 was when they changed the gauge. If yours is reading high there is a different issue. All the new ones read low- like empty at half a tank.

OK, Here you go. look where the tip of the screwdriver is. There is a little tab there that you can't really get with your finger. Push in on the tab with screwdriver and pull on connector. The tabs on the side look like locks but are only guides.

Just to verify, this is with the gauge removed, right? With the gauge installed there should be a voltage of about 3.1-3.2 volts on black/green wire. If it is, then this indicates something wrong. The 470 ohm should persist key on or off. Next step is to disconnect at rear of car and see what you have on that wire with both ends disconnected, should have no continuity to ground at all and no voltage, nothing, nada. Another step in trouble shooting can be to leave the the ohm meter connected, verify the resistance changes key on verses key off. Leave the key on and start pulling fuses until you see a change. Just for grins try this test while disconnecting the 2 wire plug on the back of the alternator. The connector in the back only has one lock, not 3 but it can be a pain getting in there to remove. I will go out to the shop and try and get a picture of where you press to unlock.

If you are getting 1.M ohms it is definitely not connected to the tank. Try this: Check voltage between Green/black and ground at gauge connector with the gauge disconnected. Try it with key off and on. Voltage should be zero in both cases. If you read voltage let me know what you get. The Green/Black wire goes from the gauge connector through a large connector up under the dash in about the middle. It then goes straight back to the tank sender. We had one where two of the pins were swapped on the connector in the middle of the dash. The mystery unit by the tank is a fuel pump controller and has nothing to do with the gauge. It is straight out of Ford Focus and can be used to control fuel pressure but Caterham does not use this feature and leaves it at a constant pressure. You can also check continuity between Green/Black at the gauge and Green/Black at the connector under the left rear of the car that goes up to the controller. You should have continuity(zero ohms) there.

Please send it back so we can check it out. The light should not come on.

The wire from the gauge to the sender is Green/Black one. Red/White is the light. Green- 12V, Black- Ground. the sender is just a potentiometer to ground. An ohm meter between Green/Black and ground will read about 70 ohms when empty and 460 ohms when full. We have seen wiring harnesses come from the factory with pins swapped. One had the Green/black tank sender wired to the alternator. @hyper7 if gauge correction unit isn't working please provide us with what it is doing. Or send it back and I will check it so we know if it is the unit or the car.

There is no coating on the cat. It comes just polished stainless like the pipes. The color is just normal heat coloration. Anything from the road that gets splashed on it while hot will remove the color like that. If you really want to remove it use a product for removing blue from chrome motorcycle pipes. Those products work just fine on stainless too. Mine look like crap after 900 miles in the rain.

For what it's worth, we talked to Caterham's chief engineer on this a while ago. They are just sending a fixed pwm signal to the pump controller from the ECU to run the pump. It does not use any pressure sensor or closed loop control. The fuel pump assembly is right out of a Ford Focus. Why they even used the controller is a mystery.

As @CBuff said, I work with Bruce, usually one day a week. Beachman Racing is alive and well. The race season this summer was quite hectic and I'm sure some things fell through the cracks. Yes, I am the one who designed the fuel gauge correction module and sell it through Beachman Racing. We also designed the replacement CSR rear suspension fittings that don't spontaneously fail. Bruce is a one man show as @Croc said except for Wednesdays when I show up to help. I am a retired guy who is helping Bruce mostly for entertainment. Since I see Bruce frequently I would be glad to relay questions. As to the G7 race cars, There is one left but it is not assembled at the moment and Bruce will only sell it to someone who will campaign it in the northwest race series since he wants to grow the field to make better racing. The G7 should be taken off the website but that is way down the priority list. We did just unload a brand new 420 SV factory built race car from the last container that will be for sale soon. Again, Bruce wants to sell that one to someone who will race it up here.

This product went live on Bruce's site today- https://www.beachmanracing.com/featured-products

Will be $75 I believe.

So when I finished assembling my 2021 360R I found the fuel gauge to be way off. It shows full at full but when it shows in the red I would only put in 5 gallons or so. It is an 11 gallon tank! After talking to Bruce and surveying other cars I found they are all that way. I set out to find out why. After some research I found that Caterham uses a standard Caerbont gauge with a custom face and uses a Ford Focus fuel pump/ sender assembly. The Ford sender is not matched to the Caerbont gauge! FFS! So I still wanted to make the gauge useful. Modifying the gauge is out of bounds and modifying the sender could be done but would be a tremendous amount of dangerous work opening the fuel tank. How to fix then. We wanted a fix that would be easy to install and affordable. Talk on forums talked of adding a resistor here or there but that doesn't really do much. Hmm. After studying the gauge and sender I decided we needed a circuit to remap the sender to the gauge. Making it really linear would require a microprocessor. This would not meet the affordable part. I put together a circuit that would shift the input and change the slope. Not perfect but small and affordable. And, no, it isn't just some resistors. It contains some active elements. Bruce researched and found the molex connectors that the newer gauges use and we had some boards made. So now we have a product that is a 5 minute install on the newer Caterhams that have the gauge with a 6 pin molex connector (I think all cars since 2012 or so) You just remove the gauge plug our unit into the gauge, plug the wiring harness into the other end, and reinstall the gauge and done. The gauge still won't be completely linear. It will stay at full until it is down to about 9 gallons (SV chassis) but then travel reasonably linearly down to having a little under 3 gallons at the top of the red ( remember there is about a gallon that is unusable at the bottom). That means at the top of red you have about 1 1/2 gallons left so it really is time to get gas. This will work just as well for S3 cars but factor everything by 0.8. These should go live on the Beachman Racing site under Featured Products within the next few days. We have 8 in stock. Brad

Believe it or not there are no real schematics available. The only thing to work with is a drawing defining the wiring harnesses. Believe me, if there was a real schematic I would post it here.

I'm all in with hiring the disadvantaged but a dyslexic color blind worker may not be a good choice in a wiring harness factory. It took us at least 3 days to figure out what was going on.