360R SV build in Northern California

[TorqueSpec]

Ran into my first real issue - looking for some wisdom from the group. ready to start the car. Battery is hooked up and ground connections are solid. When turning on the ignition, the starter button will not work unless the headlights are turned on.
 

Turning on the headlights will light up the dash, but also bring the speedometer up to 20mph and create a buzzing sound. Attached is a video of the speedo with the sound. Any guidance?

[wdb]

I have no direct experience with assembling a Caterham from a kit so please keep that in mind. But it sure sounds like a ground issue. Current is finding strange ways to get places.

 

You might try taking a set of jumper cables and clamping them here and there, the goal being to see if some part of the car is isolated electrically. After that I guess I'd dig into the harness and connections. Headlights and starter are both big users of current, maybe they have some part of the circuitry in common?

[JohnCh]

My first guess is the same as @wdb. One of the grounding points isn't tightened or the powder coating wasn't properly removed. There are three places where I'd run the jumper cable: The ground location at the back of the engine/bellhousing, the main grounding point on the shelf next to the battery, and the grounding point for the switches & gauges at the wiper motor attachment point behind the dash. The first two are easy to find. For the third, see this photo with the scuttle removed. The dash grounding point is at the top of the photo, circled in red. One caveat is that it's been a few years since I redid my under-dash wiring, so there may be a fourth point for a portion of that harness that I've forgotten about. 

 

[TorqueSpec]

Thank you, both! It was a ground issue. I forgot to reinstall one of the under dash grounds when I installed the windshield wiper motor (my car didn’t come with the windshield originally). Appreciate the wisdom and the photo!

[williamwashere]

1 hour ago, TorqueSpec said:

Thank you, both! It was a ground issue. I forgot to reinstall one of the under dash grounds when I installed the windshield wiper motor (my car didn’t come with the windshield originally). Appreciate the wisdom and the photo!

I'm so glad that's it! Hopefully you'll film it firing up!

[TorqueSpec]

Tons of progress yesterday! Ground issue sorted, engine started, shake down run completed!

 

[TorqueSpec]

And a few more photos…

[TorqueSpec]

And startup!

A few things to sort after a quick test run:

- Tach not reading

- Gas gauge not reading

- Windshield wipers worked then stopped

- Radiator fan didn’t turn on

 

All in all, a fantastic day!

[williamwashere]

Oh man that looks satisfying!!! Congratulations! It is a British sports car so the electrics will always be a little off!

[CBuff]

22 minutes ago, TorqueSpec said:

- Radiator fan didn’t turn

Sounds like you have some electrical gremlins so it might all be related.  My radiator fan stopped working on my inaugural drive.  Turns out the connector by the front cross strut shook itself loose.  I made some slack and zip tied it together.   

[empti]

8 hours ago, TorqueSpec said:

And startup!

A few things to sort after a quick test run:

- Tach not reading

- Gas gauge not reading

- Windshield wipers worked then stopped

- Radiator fan didn’t turn on

 

All in all, a fantastic day!

IMG_0859.mov

1. You can check w/ @hahuang65as he had seen tach problem before. I thought the fix was a new gauge. 
2. How much gas do you currently have? I have noticed the gauge will read zero (or near zero) when the tank is less than half full. I used this "Caterham Fuel Gauge Correction Module - 2016+" from Beachman Racing, and it fixed the problem. 
3. My wiper had the same issue and Rich sent me a new wiper switch to fix the issue. 
4. Radiator fan should turn on when the temperature reached about 95F. 

[hahuang65]

Exactly what @empti said for all points.

 

I had to get a new tach although you can check your dipswitches. Rich had sent me a document but I can't seem to find it. If he's your dealer ask him about it.

 

Definitely get the fuel gauge correction module.

 

I also had to get a new wiper switch though I haven't installed it yet because I switched to the aeroscreen.

 

Yeah run the engine until it gets hot,then the fan will start. In fact let it cycle a few times...the fan will cool the radiator enough to shut down,then it'll get hot enough to turn back on.

[williamwashere]

I am so surprised that they still haven’t fixed the fuel gauge without some weird aftermarket man in the middle. Seems like an obvious problem with a customer need Caterham should address themselves! 

[Slonie]

Huge news! Congrats on getting it running. I don't trust the fuel gauge in my car at all (with similar behavior) but unlike a 2016+ car I'm not sure there's a cure.

Hope to go for a drive soon! 

 

(my car is back up on stands to address a noise coming from the rear suspension, which really means I'm long overdue for a torque check on every bolt back there...)