Faulty Starter Motor Solenoid

[Bilbo]

Hi all

 

Well I have read most of the postings on K series Starter motors. Think that's the one I have the very little one. Seems my solenoid on the fitted last year little starter motor is playing up.

 

Dead ☹️ on 1 to 2 turns of the key then fine. None of the terminals seem loose and the earths are good.

 

So will my BD have the same solenoid as the K series that's to say are they all the same starter motor with a different mounting etc 🤔

 

Anyone know who can supply me with one in south London or near area 🤔.

 

I would like to repair it before Saturday and Curborough !!!

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.

[SLR No.77]

Before spending anything else, do the "Paul Richards" fix with an additional relay. Check on the archives - it will cost a fiver and take 30 minutes to fit. Only after you've added the relay can you decide if your starter is duff, and I'm sure you can sort that before weekend

 

Stu. 😬

[Bilbo]

Hi Stu

 

I take it you mean

 

"K Series Starter - The Cure?? "

 

here

 

Regards

 

Bill

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.

[Chris W]

Bilbo

 

Before fitting the additional relay (which I recommend too that you do fit anyway) you can do a quick test to discover whether the fault lies in the solenoid itself or in the circuit to the solenoid.

 

1. At the solenoid, you will find a thickish brown/red cable which gets its power to operate the solenoid from the MFRU. (The black box mounted on the ECU on K series engines).

 

2. Connect a similar thickness long wire at the solenoid to the same terminal as the brown/red wire. You can leave the original brown/red connected at the same time.

 

3. Making sure the car is out of gear, switch on the ignition and touch the other end of this temporary cable to the battery positive. If the solenoid is OK, the engine should start every time you do this.

 

If it does start reliably every time, the additional relay should fix the problem - which is probably dirty relay contacts on the starter relay inside the MFRU. If the solenoid is still intermittent, then the fault lies with the solenoid itself and you should check all the connections to it or substitute a new one.

 

Chris

 

1.8K SV 140hp see it here

 

Edited by - Chris W on 12 May 2003 02:05:48

[SLR No.77]

That's the one, Bill.

[Chris W]

Bill

 

There's another thread on this here which simplifies the wiring.

 

Chris

 

1.8K SV 140hp see it here

[Bilbo]

Hi All thanks for your helpful replies.

 

I first have to say its not a K series engine, just the same mini starter with a different mounting plate and final engagement.

 

As my car has 1988 wiring it does not have the same wiring system as the later cars.

 

The solenoid has a red/white wire direct from the ignition switch no MFRU. Plus a nice big rather long wire from the battery to the Battery Cut Off Switch and then to the solenoid.

 

So what's a MFRU when its at home and how does the later system vary. 🤔

 

So there are no additional relays as the MFRU posting seems to imply.

 

However, I switched the ignition on tonight and ran a wire from this spade connection on the solenoid and touched the battery +ve terminal clamp nothing.

 

When it was touched directly to the post on the battery it turned over every time, well missed once.

 

So it looks like too much volt drop in the wire from the ignition or rather a bad connection at the switch or the connection to the solenoid. Both are those rather naff crimp connectors that tend to corrode so maybe thats the problem.

 

However, this does not explain why the touching on the battery clamp failed. The +ve and -ve connections on the battery are free of corrosion and its a new battery. Its a new battery have just changed it because this was happening and has a very good charge. The old one was at least 5 years old. One alternative is the connections to the Battery Cut Off Switch have some corrosion.

 

All this was with the engine cold it does seems much worse after a run. . Also its always better after the first try so none of the above may be relavant hence me thinking it was the solenoid.

 

I would have like to investigate further tonight but I have a report and a set of minutes to get out for the morning. Its a burn the midnight oil evening. ☹️ Actually that's why I did not look further all weekend (sigh it was 2 more reports on Saturday and Sunday) ☹️ Still thats what happens when you have holiday its just all there when you get back 🙆🏻

 

Oh, one other thing anyone know a source of that silly tiny screw that holds the rear of the ignition switch together to the main metal part. Mine fell out some time ago currently held together with tie wrap and tank tape. This is not the cause of the problem. Thats the first thing I checked. ❗

 

Alternatively what size is the screw 🤔

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.