New owner - a few issues - help!

[Richard_420R]

Hi All,

Had my 420R since October and having a couple of niggles that I'd welcome some input on.

I got my 7 from Oakmere which is a bit of a trek from East Yorkshire when I am based.  However I got them to look at my niggles at the running in service but it isn't fixed.

The main irritation is that my wipers just stop from time to time.  They'll work fine then they'll start wiping in a 'laboured' way and then refuse to move at all.  People have told me "the wipers aren't very good anyway" etc but I think there must be some sort of electric gremlin- there is no motor noise, no movement at all.

Second issue I had was misfiring on track day when very hot.  Engine runs fine until I've done a dozen laps then I was losing power as if it was hitting the rev limit lower down.  Oakmere think this might be the imboliser shorting to ground and have currently disabled it for me to test.  It hasn't done it again but then I haven't been on track since so I haven't been able to properly test.

Lastly the speedo started jumping and now is just sitting dead at zero.  When I researched this, it seems likely an earthing problem - what do people think?

So I am wondering whether all my issues are connected and to do with a faulty earth.  The wipers are simply non-functional and silent when I press the button and it does not seem that they have power.  Also is it possible that an issue like this only happens when the car has heated up?  The speedo tends to work for a while as do the wipers then after about 15 minutes of spirited driving they just stop.

Be interested in ideas ... plus does anyone know anyone near the East Yorkshire area who looks after Caterhams - Northwich is just to far to keep popping over to - plus if I have no wipers, it is 'interesting' in winter conditions!

Any and all help appreciated!

Rich.

[Jonathan Kay]

Welcome.

Have you got a multimeter and a wiring diagram? (The current ones are on the Caterham site and I have a collection of previous.)

Are you sure that you want to DIY? NB your consumer rights regardless of any "warranty".

...

Wipers

This is not normal. Does it happen whichever speed you select and if you ask for a single wipe? Start by checking the feed (voltage to a good earth) and the earth (resistance to a good earth) at the motor when they are working normally and when they fail. 

...

Speedometer

Is everything else, including all instruments, working when this fails?

There is a Workshop Notice for older cars which improves the wiring, but yours shouldn't need that. Start with Part B of John Vine's Guides and the subsequent note about the new style of sensors and check if the telltale lamp on the sensor is showing anything when you rotate the wheel. 

Jonathan

[Richard_420R]

Hi Jonathan,

thanks for the response.  Ideally I would get someone to do this for me hence the ask whether people know of anywhere trusted in the east Yorks area.

to you questions - yes when speedo is dead, all other functions work (except wipers).  And is there a simple guide for accessing the front scuttle?  Whilst I'm not a total numpty, I'm by no means proficient re working on cars myself!!

cheers, R.

[Jonathan Kay]

Morning.

A few edits now made to #2 above, including one more question.

Experts, please: how accessible is the wiper motor on Rich's Seven? Thanks.

Jonathan

 

[CharlesElliott]

I would suggest faulty earth.

The dash instruments and wiper motor are earthed under the dashboard on the passenger side. Hard to get to without removing the scuttle to be honest. The other earths are in the front under the front brake union, battery to chassis and engine to chassis. Check them all and that the powder coat has been removed so that the connector can make good connection with the chassis. 

[Wrightpayne]

Re wipers - does it have an intermittent feature? On my much older car a double flick of the wiper switch induces the intermittent wipe. I thought mine had failed in a downpour! 

Checking earths always a good starting point.

Ian

[Jonathan Kay]

If the wiper motor terminals are hard to access:

• Let us know about the effects of different selected speeds.
• Check the wiper motor earth at the end you can access, as above. 
• Check the output voltage at the wiper switch on each setting.

Jonathan

[Richard_420R]

Hi Ian,

I don't know about the intermittent feature - I hope I'm not being daft but no amount of flicking the wiper switch gets it to move at all - both speeds. 

Feels like a faulty earth is to blame but not that confident taking the scuttle apart etc - anyone know of somewhere in Yorkshire or nearby that does this sort of thing?  Otherwise I suspect I'm just going to brave the drive to Northwich again and hope they get it sorted this time!

Rich.

[Richard_420R]

Hi Jonathan,

Let us know about the effects of different selected speeds.

- before it stopped, the faster speed was more reliable and less 'sticky' but now nothing happens at any switch positon

Check the wiper motor earth at the end you can access, as above. 
Check the output voltage at the wiper switch on each setting.

- need to figure out whether I'll DIY or find someone to help with this.  Is there a simple 'access to front scuttle' guide somewhere?

[SM25T]

Sute you don't need to remove the scuttle to get at main earth point. Use phone camera to look under dash while sitting in seats. If you have a warranty ... use that first.

[Manstein]

There's a garage on the airfield estate at Kirton in Lindsey which does a lot of Caterham work .

http://www.ctsmotorsport.com/

[John Vine]

Hi Rich, and welcome.

 Is there a simple 'access to front scuttle' guide somewhere?

Not that I know of.  Some owners remove all the scuttle rivets to make the scuttle detachable.  I've not done this, and I don't recommend you do, especially with a car under warranty!    If you carefully prise out the switch from the dash, you'll be able to get at the terminals for voltage testing. 

Does your screen-wash switch work ok when the wiper doesn't?  If not, check that the fuse (shared with the wiper motor) is firmly inserted, and that the wires behind the fuse block are properly located.

...anyone know of somewhere in Yorkshire or nearby that does this sort of thing?

Have you tried contacting the Yorks North and East group?  I'm sure a local member would be very happy to have a look at your car to see if there's a straightforward solution.

Agree with the other advice re earthing and speedo.

JV

 

 

 

[AG2728]

I had exactly the same misfire issue. New 420R registered this year. It was fine on the road but I went to a trackday at Croft and would run great for about 7 or 8 laps then would frustratingly start to misfire at high revs. It couldn't pull more than 6k.

Cooled down and it would be OK for another few laps and it was like this all day.

I rang Oakmere who suggested a possible immobiliser issue. I was very sceptical about this to say the least and even went down there to buy myself a set of coil packs and plugs to swap out at my next trackday as a process of elimination. I also booked it in for the imobiliser to be removed, as I had nothing to lose.

Have done 3x Oultons and a Brands Hatch trackday since the imobilser went and the issue hasn't reoccurred. I have purposely stayed out for more than 30 minute sessions to provoke it but all seems good.

I would have bet money on that not being the problem, but it seems that it was.

HTH

Andy

 

 

[Jonathan Kay]

Very interesting.

Rich: What sort of immobiliser fob do you have? Does it look like this?

https://www.google.com/search?q=SITE%3ALOTUS+7.CLUB+IMMOBILISER+MISFIRE+DURATEC

Jonathan

[ChrisC]

Hi Richard 

Having owned two post 2015 Duratec cars, I can tell you any published wiring diagrams are way way out of date, so are nearly useless.   

The Immobiliser isn't on the wiring diagram for obvious reasons. 

My late 2015 360R kit, didn't have a "MFU" and didn't have multiple connections between he Engine and Chassis loom, as depicted in the wiring diagram, later models (from 2016) had updated instruments and a newer ECU, and still the wiring diagram isn't updated.   

That said I believe the wiper wiring to be accurate.   

What age is you 420R?

I think the earth connection near the wiper motor would be a good place to start.   That earth is connected to a lot of components and is near the immobiliser location.   

I don't think its the cause of your speedo problems.  For that check your car has the earth mod fitted, and check the version of the sensor you have.   

If you need any pictures, I don't have any knee panels fitted to my new build at the moment so it will be simple to get them for you.

 

[ChrisC]

Also your misfire, I spoke to the factory about the changes to the engine earth and was advised that the spec was changed when a car had a misfire when the indicators where used, that took days to resolve.  They changed the earth cable default locations, so where do your battery / engine earth cables run from / to?

Build manual recommended Battery to Chassis and Chassis (near LHS engine mount) to Engine, Factory now just go Battery to Chassis and Battery to Engine.  Worth a check I guess, but Oakmere should be all other that one.  

[John Vine]

Re the misfire, were you able to pin it down to a specific cylinder or cylinders? 

...when a car had a misfire when the indicators where used...

That's an interesting one.  A similar thing happens with the speedo (brakes as well as indicators), and the cure is to establish a better earthing point for the sensor (as described in WN572) .   I was wondering if a coil driver circuit could be similarly affected?

JV

[ChrisC]

Hi John 

This "When a car had a misfire when the indicators where used" was a comment made by a respected CC factory member of staff, when he showed me around the factory two months ago.   I was asking all the technical questions I could throw at him, and the change to earth lead location was one. I spotted at the CC open day this year on the yellow 420R with the new cage, so wanted to find the reason why.  I don't know specifics about the car that had the original fault. 

Chris. 

[Richard_420R]

Thanks John,

yes already tried the fuse route and the pump runs fine for the screen wash.

have contacted the local group - I'll see what comes back.

i think most likely I need to book another Northwich visit to get his all sorted under warranty.

 

[John Vine]

Thanks, Chris.  You were honoured to get a factory tour.  That last happened to me when Len Unwin and Tim Ward were in charge!

JV

[Richard_420R]

Hi Andy,

yes the guy at Oakmere told me "he'd seen it before" re the immobiliser and that's why he has currently bypassed mine.  I haven't had a chance to try it on track but your symptoms are identical to mine so fingers crossed.  I guess he was referring to your situation!

feels like the wipers are a wiring/earthing issue.  By the way it seems to also happen more when hot - I'll try them again but I'd like to get they'll work when I try them next - only to stop 10 minutes later.  Is that a thing??

its a new 420 - built 2019 (and registered in September). 

Rich. 

[Richard_420R]

Andy, did you replace the immobiliser or just have it removed?  Mine is currently bypassed but he was suggesting a replacement if it worked.  Be a pain to lose the immobiliser for insurance reasons etc 

[AG2728]

Hi Richard

I had the immobiliser bypassed and the loop removed. I wont bother with a replacement and will have to rely on my removable battery kill switch and removable steering wheel as deterrents.

My thoughts are that a Caterham is nowhere near the top of the TWOCCERS league table. Aside from the fact it doesn't even have any doors or a steering lock.

If someone wanted it that badly, the reality is that they could just lean in, push it into the back of a van and drive off.

Andy

[K7 VCT]

Send it to oakmere to fix it under warranty ?

[Rogercsr7]

Email sent Richard with area group info. Manstein has given you the CTS web address, I've added a bit of detail. Surely Oakmere need to sort this for you? Get in touch if you need help getting it over to them.