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#1 Starter motor M45G

Posted: Mon Jun 20, 2016 7:58 pm
by Durango2k
Today I tried to crank my engine.

The starter button only gave and gives a solid CLONK, and thats about it.

When I connect the battery plus - post to the large copper nut on the starter however, it turns the engine over fast.

So, the motor is fine.

Am I right thinking that 3 months ago the starter motor did work nicely on the bench, but since then the solenoid switch function has failed internally ?

What would you do ? Can the solenoid himself be dismantled and / or adjusted ? Iirc I could take it of the motor with no big fuzz. 2 bolts some wiring of it came. Then I could pull the centre actuator. And then ? Wasn't there a copper contact behind it ?

Sadly no one has spares for this model, last time I had to make my own coals for The Beast, but iirc. I could not get a solenoid.

Here's a pic of the mounted starter- maybe I got the wires wrong ?

I do NOT have a single thick wire from the battery post to the starter, all I have is a 4 mm one which comes out of the loom. Maybe this (brown) one is just the solenoid, and I have to make a new battery-post-to-starter-motor-terminal cable ?

Image

Carsten

#2 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 1:01 am
by Durango2k
Seems I found it- there is item C24497, "starter motor battery cable" which has no spade but two ring connectors which gives me the strong feeling there is a thick seperate plus wire and it wasn't there on my car. Strange. Why should it have been removed ? Maybe it was so rotten I dumped it forgetting to take at least a note ?

Which way does it go along ? Front way- along the frames to the fron, cross, and back, or through the cabin ?

Carsten

#3 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 11:49 am
by cactusman
Hi Carsten. Yes. There should be a very thick wire from the battery to the starter. Very thick!! Mine follows the engine frame, across the picture frame at the top and back along the other engine frame and down to the starter. Mine is a 62 car but I am pretty sure all the six cylinder cars have the same route....others wiser than me will know. Sure it does not go via the cabin though.

#4 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 1:51 pm
by Durango2k
Hi Julian,

I think it may be a 10mm2 ? Wire ?

I do have a high quality starter cable here, which has lost one clamp so maybe I can use this, and have two ring connectors clamped on it. Or I'll buy the SNG version which has the advanteage of being the correct (brown) colour.

I thought they may have routed it via the cabin because if it becomes chaffed your car may well burn down in seconds. This wire is unfused, full battery power on it. The way through the cabin is shorter and maybe better protected.

Regarding my car, it is not there nor can I see it on any picture (not found yet). Freaky, on an otherwise almost untouched car, who would remove solely this wire ???

Maybe a PO had several E's and swapped or simply took what he needed....that may explain why the crank breather pipe is gone, together with the upper part of the aur filter bin, and the lower ignition coil mount...

Carsten

#5 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 3:30 pm
by BRM
Carsten,
It is as Julian says the main power cable from the battery to the starter. It will be the same thickness as the short piece from the solenoid to the starter in your picture. I shouldn't worry about why it's missing - it's not there and until you replace it the starter won't work. I made a new one, just bought a suitable length of starter cable and soldered ring connectors on each end.

Mine also runs from the terminal post by the battery round the front of the frames and back to the starter. I think that's standard. Sure it could start a fire if the insulation chafes through but the same can be said of any live wire on the car.

Fusing it would not be practical as it is designed to carry a very large current when the starter is operated. That's why it is so thick.

#6 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 3:42 pm
by Durango2k
Hi Brian,

Of cause you're correct regarding "any live wire".

It's just this case here that the whole amount of energy inside the battery could be sent through this cable in, say, a minute, so it would literally melt. The thinner cables may go up in smoke, but not withstand so self - kill themselves after a few seconds.

Academic of course.....I won't try it. I just remember to have seen a moovie where a wrench fell onto a battery. Ouch !

Carsten

P.S. In fsct it should be even a bit thicker then the cable from solenoid to motor itself. It is very much longer....

#7 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 3:45 pm
by cactusman
Mine is black. If you make your own get at least 25 and pref 35 mm sq cable in terms of conductor area which will be about 10 to 13 mm in diameter or thereabout. The thicker the better to minimise voltage drop as it is quite a long cable run. Use wire ties to secure to the frame. No point fusing it....they never are. You would need a 400 amp fuse!!! Solder eyes at each end and the job is done.

#8 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 4:10 pm
by Heuer

#9 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 4:18 pm
by cactusman
Yep...ideal I would have thought.. bargain at £23.

#10 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 4:25 pm
by Durango2k
Yes thats cheap.

Depends a bit on what happens on Thursday regarding the pound exchange rate :-)
And freight to germany of course.


Carsten

#11 Re: Starter motor M45G

Posted: Tue Jun 21, 2016 9:47 pm
by PeterCrespin
Durango2k wrote:It's just this case here that the whole amount of energy inside the battery could be sent through this cable in, say, a minute, so it would literally melt. The thinner cables may go up in smoke, but not withstand so self-kill themselves after a few seconds.

In fact it should be even a bit thicker than the cable from solenoid to motor itself. It is very much longer....
You are a living example of the education benefit of forums Carsten :-)

You started by asking should there be a heavy starter cable or is a thin control wire all it needs? Then within a few posts you know enough to suggest Jaguar's choice of fat copper wire was probably too thin! At this rate, tomorrow you will be designing ECUs and teleportation machines :-)

#12 Re: Starter motor M45G

Posted: Wed Jun 22, 2016 8:15 pm
by cactusman
We don't want ECU's in E types!!!!! Stick to those trusty SU carbs. You can fix them with a few simple tools instead of plugging in an OBD box at several hundred quid....

#13 Re: Starter motor M45G

Posted: Sat Jun 25, 2016 9:30 pm
by Durango2k
I had a look in my spares edge and found two old wires from starter cables (to bridge between cars).

They are both 20mm2, or 5-6 mm diameter.

This is of course less then 25 let alone 35mm2.

The short wire between starter and post on starter is 6-7 mm diameter which is about 30mm2.

Seems I should get a 2m piece of soft car capable 35mm2 considering length.


Carsten