Scottish Elises

everything seems to be fine fuel pump primes all the electrics seem to work but the starter motor won't go (I don't even hear a click) does anyone have a copy of the electrical diagrams so I can start tracing the fault.

pm sent,

Kevin.

It's easy to hot wire the starter at the back of the starter - remove the small spade connector and then use a short piece of cable to connect the exposed spade terminal to the large stud nearest the boot wall. This will make the starter turn immediately, whether or not the ignition is on, so be careful!

So, if you turn on the ignition, clear the immobiliser and hotwire the starter, the engine should start.

This is a good place to divide and conquer the problem.

Cheers,
Robin

Tried to hot wire the starter Started to play about with this over the weekend.

Alas howevcer I didn't go back and re-read robins post so I disconnected the wrong wire

Yesterday when I had the car connected to the clio i was getting a click off the solonoid so I took the battery out put it on charge and set about fitting my quick release battery clamps. These make popping the battery an peice off piss alas however I can no longer get a set of jump leads on.

Anyway I popped the newly charged battery in and....... Nothing not a sausage - bog all Thinking back to robins post rather than checking it and remembering wrongly I disconnected the big red wire and tried again..... and got a rapid clicking noise. hmmm so I ran a cable heath robinson stylee straight from the battery to the starter (where the thick red cable came off) and she starts no problem.



I am confused as to why the solonoid wouldn't work when the red cable is connected but does work when it isn't
Suggestions please

If you have a multimeter I suggest:

Leave battery installed, but disconnect -ve terminal (leave +ve terminal hooked up).

Leave all other wires connected the way they originally were.

Measure resistance from the big red wire at the back of the starter to the live terminal on the battery. You may need to use a jump lead or similar to extend the reach of your multimeter probe cables. You should get the same resistance that you get if you just touch the probes together. Even 0.1 ohms more would be quite a lot - remember V=IR, when cranking the starter might take 200A, so V = 200 * 0.1 = 20V (which is 8 more than you have!).

Next disconnect the +ve terminal of the battery and reconnect the -ve terminal of the battery. Measure resistance in the same way from the -ve battery terminal to the body of the starter motor - you may need to use the tip of the probe to scratch the housing of the starter to make sure you get good contact. Again you should see no more resistance than when you touch the probes together.

If either path shows high resistance then I would go for checking all the terminals are clean and there isn't loads of corrosion around the cable crimps. If the high resistance path is in the -ve side then you're probably looking at earthing strap problems.

Cheers,
Robin

Which red wire needs to be disconnected to make it crank?

When it does crank, is that you hotwiring it at the back of the starter, or is that you turning the key?

Cheers,
Robin

The big fat red one that looks like it comes from the battery as it looks like it can take a lot of juice. When disconnected you get a clicking from the solonoid (?)

Off to clean the terminals

I was getting 4ohms across the + side so I cleaned everything up and she now starts.

Thanks again robin

Would there be any problems running a pair of these in the back running one from the earth mount on the chassis and another coming off the starter motor ? it would make things alot easier should I ever need to jump start the car.

There is no need; you can clip the -ve jump lead to the earth strap or earth stud near the ECU; you can clip the +ve jump lead to the stud on the back of the starter (the one nearest the boot).

However, if you do want to run some more convenient terminals you need to make very sure that the +ve is secured (there are no fuses in that path) and obviously cannot be mounted through or near any of the metal work.

Cheers,
Robin