Heat shielded wire

[Matt B]

Hi

 

My 98 K series suffered from the dreaded click, so i carried out the relay mod and it was fine last year. However it has recently started clicking again which i attribute partially down to the wire to the starter motor. I just used std electical wire which i am guessing has started to degrade already.

 

What would be the best wire to replace this with and where could i obtain it from?

The car recently caused much hilarity when it wouldnt start and just clicked at a recent MX5 owners club meet - soon wiped the hilarity off their faces when i got the car started and took them for a lift 😳 🥰

 

Many thanks

 

Matt

 

Edited by - Matt B on 16 Jul 2009 10:29:43

[Bricol]

Have you tried replacing the wire you think is dodgy with nother lump of "normal" wire first, to see if that sorts it?

 

However, since replacing the whole circuit on mine with "normal" wire, I've had no trouble. New wire from battery, via a new fuse in the fuse box, to a new relay in the car. New earth from relay to car. New wire from ign switch to trigger new relay. New wire from relay direct to starter terminal. ie I've removed anything to do with the original MFU control of the starter. I do use a proper terminal crimping tool though, not the usual stripper/crusher thingie you can buy for a few quid.

 

Power lead from battery to starter is original 8 yr old one.

 

Bri

[Paul Deslandes]

Matt

Although its essential to use properly specified and correctly rated automotive wire for car wiring from a current capacity and insulation/safety point of view, normal domestic cable, provided the conductor is man enough to carry the current without significant voltage drop and heating-up, won't deteriorate as such. The copper conductors don't 'evaporate' (unless you really get it wrong 😳) and, provided the insulation is intact and safe, should still carry the current. If your original problem has returned I would suggest you check the terminations which should have the correct crimped ring, spade or Lucar connections on the ends. This is usually where the problems show themselves. I personally like to solder multi-strand conductor terminations in addition to the crimp but this is frowned upon in many professional wiring environments as vibration can cause the soldered part of the conductor, which is now solid rather than multi-strand, to fatigue and fail.

 

I'm definitely not advocating the use of domestic cable in car wiring as its unlikely to have sufficient rating for anything other than very low current applications and the insulation is not suitable for the heat, solvents and vibration encountered. My point is that your problem is likely to be elsewhere provided the wires are correctly terminated but I would strongly recommend that you replace with 'proper' auto cable as soon as possible. Even a small resistance in a poor connection carrying a few amps will cause sufficient voltage drop for the load not to function correctly.

 

Paul

 

 

[Mick Day]

Matt

 

You dont say whether you have totally bypassed the MFRU relay? If you haven't you may like to consider doing this as well.

 

Secondly try taking the lead that goes to the starter solenoid off your new relay & touching it to the positive of the battery; you may need a little extension & make sure the car is in neutral. If the starter fires up then that proves the lead/starter is OK. Your new relay may be at fault so good idea to replace it on a regular basis. Also check your ignition switch as this can wear as well.

 

I treat the starter circuit as a consumable & replace the wiring/relay on a 3 year basis.

 

And finally I wrap all the wiring that gets close to the exhaust (alternator, battery, starter etc) in this: here

[Mick Day]

Oh & the wire I use for the starter solenoid is 28/0.30mm, 2mm2, 17.5amp; again available from VWP.

[Steve Campbell]

I'm in the process of sorting mine. I'm routing the wire below the starter motor (away from the primaries as much as possible) and will be using a piece of "heat blanket" around the starter motor/solenoid (without covering completely) to give a bit more protection. Don't know if this will help but I've seen a few with this route + blanket on them. I got the wire from Maplins with suitable Ampage....size.

 

Steve Campbell

P889 GRR