Paul, the solenoid is good. All symptoms indicate internal short at the field coil. A new gear reduction starter is on its way from SNG but i will restore and keep the original starter.
Thanks Jim for the offer ! Sure I will keep the original one, it will be part of the car story. But a new gear reduction starter will bring the engine to life. Fully reversible upgrade.
Dick, I had a problem with a starter of a Renault 4CV from 1958, the solenoid was broken (intermittent problem with the contacts) with the additional drawback that for that particular starter (Ducellier) the solenoid could not be found anywhere, and a new (reconditioned) starter would cost … 700 Euro ! This for a car that the market value is 10 times that . You cannot open that solenoid without cutting it, very difficult to put it back together . In the end, after months of searching i found someone in France who had an old stock unit at home. Installed and all ok.
A solenoid normally starts giving intermittent problems before ´giving up´
The problem with the e-type starter is completely different . (again, much likely field coil internal short) . Springs and brushes and anything else really seem like new, rather impressive as the car has about 110.000 original miles.
. All symptoms indicate internal short at the field coil.
Remove the field coils from case.
Check for continuity, re enamel the windings, get new " fish paper", between coils and case, and reassemble.
Indeed. There is continuity and no short with the starter case but internal short is difficult to detect with an ohmmeter as I do not have the specs for the original resistance of the field coil. I will bring the disassembled parts to someone who may have the specs and a ´grawler´ for proper identification of the problem, Meanwhile a gear reduction starter is on its way from SNG.
I just finished installing a new Gear reduction starter ´LUCAS´(Lord of the Darkness!) from SNG. Installation was quite straightforward as the unit is much lighter (3x ?) and smaller. I did even manage to put back the plastic cap covering the hole on the transmission tunnel, which is inserted out-in and almost impossible to reach from the outside .
I still need to go for a spin but the engine turns well with a more ´civilized´ sound. Moreover, it draws less current and seems to turn engine faster. (Although I have never had starting issues with the original motor - until it failed)
Will I have no problems after my test drive hopefully during the wend I truly believe this is the way to go.
This is why:
You can see the original motor in one photo. All seems visually impeccable . Even a simple test with an ohmeter did not detect a problem (for continuity and shorts of the armature), but the armature was actually dead after being tested in a ´growler´.
The motor has plenty of insulation components, and on V12 after 50 years they all become brittle. One day they will fail, it is a matter of time - and luck. Rebuilding it would be far over 600 Euro (or USD) and you’d need to find a reputable company. You simply should not rely on a motor baked for 50 years in a V12 engine bay.
A 100 USD rebuild (as written here on the list) is basically a fix, cleaning, new brushes or solenoid change at most, but you will still get a baked motor back.
That would be ok if the motor could be easily removed or on a manual car, but on an automatic it will leave you stranded. I see no arguments to take that risk.
That said, my old Unit is well packed and will be part of the car - up to the owner then to rebuild it if he wants and put it back, fully reversible .
I hope this helps !
You can see that at the end of the windings in the armature the insulation is partly gone , touching it it will crumble …this is probably what happened inside , although not detectable with an ohmeter but under high currents only :
So today I went for a test drive with the new high-torque starter motor, It cranks effortless and the engine starts with a quarter turn. But i never had problems with the previous motor, although a good 1-2 turns where needed or so it seemed.
NB it seems to me that the new starter desingages as soon as the engine gives a sign of life (a couple of explosions) while the old one was more persistence… So notice a slight different behaviour : with a warm engine , a couple of explosions may not be enough to keep the engine turning, so it now helps a lot to give a little bit of gas when cranking , for a fast (immediate) start . That was less needed with the old engine .
Here you can see what would be needed to fix the old motor, in my case (rewinding the armature ) . The armature in.the video is very similar to the V12, Eben if it is for a truck !
As you can see it is a very labour intensive job, the least expensive quote I, got only for this armature rewind, was 300 euro in Portugal, with no guarantees (ex. something may go wrong when removing the collector) . Then of course, you’d take the opportunity to redo insulation in field coils, new solenoid, etc. So it is a no brainer unless you want to stick to 100% originality - Which I will do in any case by keeping the starter motor aside.
This was today’s test drive
One can, with fortitude, repair almost anything…AND his technique is perfectly safe.
Indeed ! Would I live in India …
Hello - is this where to ask a question about how to test a starter, or do I ask somewhere else? A starter was given to me and I do not know if it is good in case I need it at later time. Thank you
Get a 12 Volts loaded battery and a pair of jumper cables . Connect the minus anywhere to the metal body of the starter and the plus to the free 1/2 inch nut on the solenoide .
Then connect a thick electric wire or third junper cable also to the plus of the battery . With the other end touch the free contact of the solenoide, the small one with a screw… Be prepared for a spark and the solenoide engaging followed by the starter turning, will it be ok .
NB: DO IT OUTSIDE ON THE GROUND OR MAKE IT SURE THERE IS NOTHING INFLAMABLE AROUND AND THE STARTER CAN’T MOVE OR FALL .
That is very easy sounding. Thank you for answering. I must start learning such things to become handy later on. Thank you
Unfortunately, and as outlined by the OPs conclusions, even a successful “no load” test of spinning the starter with a battery is not fully conclusive of whether a starter is good or not.
The internal electrics can fail to be acceptable under maximum current, which is hundreds of amps, but spin fine under a no load test, which only requires a few amps
Some auto electricians have the equipment to perform more thorough tests that are more likely to detect the reliability
I found this out the hard way once, as a (reduction starter) on another vehicle (not Jaguar) failed, but was ok when removed and tested. I replaced the worn brushes anyway, it spun ok, installed it, did not work, had to replace the unit
Having said that, an experienced expert auto electrician I know told me reduction units are no more, in his opinion less reliable than a rebuilt Jaguar unit
I note the OPs comments on heat and age related insulator breakdown, in addition, some parts, such as the over-running clutch are very hard to get, solenoids must also be rebuilt
Thank you for the extra information. I will do the easy sounding test and if that is good results I will bring it to a shop for test with much load. Thank you for your help.