Starter issue.....

[lotusolly]

I wanted thinking the same as Heineken
As the lights are dimming and pulling down the voltage, could it be something mechanical catching and preventing the starter from spinning?
Olly

[britlude]

just to round up this thread (hopefully)

replaced the starter inhibitor relay...

IMG_20210508_154543 by NSX Jon, on Flickr

and so far, all seems well

[Old guy]

If the replacement starter cut relay fixes the problem, that would be perfect. If it doesn't, I suggest having a close look at the spade connector (S terminal) on the starter motor. Given the location, I recognize that 'close look' is going t be a problem. The fact that the starter circuit restores itself each time you disturb this connection suggests that it might be suspect. It is possible that the wire strands in the crimp on the female terminal have fractured or that the raised section on the female terminal that retains the female terminal on the male terminal has deformed resulting in a poor connection. It is also possible that there is an intermittent electrical connection between the exposed portion of the male terminal and the actual solenoid winding. Applying some electrically conducting grease to the spade terminal may help with the problem if the problem is at the spade terminal proper. Penetrox A and Ox-Gard are two conducting greases. Do not use dielectric grease because it is an insulator.

With luck its the starter cut relay and the problem will never re emerge.

[britlude]

Well, i was having an issue that prompted the relay swap, where i used the temp hardwired starter wire to spin the engine over , but touched nothing else, including the terminal.... And since the relay swap, no issues, touch wood, cross fingers, chuck salt over my shoulder, etc!!!

[britlude]

Starter issues seem to be flavour of the week!!!


The car has been standing a week and this morning it didn't want to turn over... OK, low battery is to be expected but I'd hope for a starter solenoid click or something.... As it was repeatably not turning over I had a chance to get the multimeter out....


Measuring the engine bay battery jump terminal to ground I had 11.7 volts, OK its down, not unexpected


Turning the key to the start position the dash lights dimmed a little and gauge values dropped, and I measured 11v at the jump terminal.... OK, but not disastrous


Now, I still have a lead from the starter motor low tension terminal so I can jump start it direct, but it also means I can read the voltage seen by that terminal when I go to start it....


5.8V..... Hmmmmm not very good at all. There must be a high resistance connection somewhere in the starter motor circuit...


Ignition on, I touched my remote start lead to the battery jump terminal and the starter span , and fired up straight away.... More investigation required...


On an aside, when we were driving around I did notice the dash volt meter drop from 13v to 12.5 v for a couple of seconds, repeating but not sure how regular, so i put the voltmeter on the cigarette lighter and that showed a healthy 14v, so guess the gauge feed is tired (replaced the caps during first lockdown!)

[Old guy]

The starter circuit is exceedingly simple.



If you have good voltage at your jump start terminal that means the battery connections are good.

Fuse 29 is the IGN1 circuit which also powers up the dash cluster (voltmeter). However, if you were having problems with the IGN1 circuit you would likely have other significant problems (the ignition coils are supplied off of that circuit); but, it is easy to check the voltage at the fuse when attempting a start to confirm whether the problem is there or elsewhere.

That leaves the ignition switch and the starter interlock relay. I would check the ignition switch first just because it is easy to get to (relative to the interlock relay). On North American cars the interlock relay is well buried under the right dash area of the car adjacent to the stack of control modules.

[britlude]

today i had a quick delve... I disconnected the main power feed to the starter, so i could turn the key and monitor what was going on without the car actually starting...

whilst chasing the issue last year, after changing everything else, i have already replaced the interlock relay, after a detective session trying to find it!!! so i know where it is, and that it should be good (i also slotted the mounting bracket so it's a whole lot easier to remove!!!!

and after digging it out, probed it and had approx 7v at the contacts when it's trying to start....

checked the main feed fuse just in case too! full battery voltage coming out of that... Next I went to the ignition switch, that seems to have battery voltage leaving it when I want to start the car.... So somewhere between the switch and the relay seems to be losing the voltage.....

yup, It's not the most complicated of circuits.... Main fuse, ignition switch, inhibitor relay, loom link via the interior fusebox, starter solenoid... 12v should land at the starter solenoid, not around 6v!!! I shall have to check continuities to find the resistance next... or feel for a warm joint.... maybe an excuse for a cheap thermal imaging camera