A Cautionary Tale..

PostPost by: pereirac » Sun Apr 24, 2005 9:46 pm

I recently discovered that my headlamps were wired back to front giving me dipped beams when I selected main and vice versa..(the car had a new wiring loom recently and this was the first time I had driven it in the dark), Fixing the problem looked easy enough, pull the mass of wires down from under the dash and swap the wires to the switch on the steering column. Looked easy enough. Did this and tried the headlamps a few time, running the engine to get the headlamps up. Everything worked, so far so good.
I then went to start the car to put it away in the garage but the car would not start. The solenoid clicked over a few times but nothing else. Looked like a flat battery or stuck starter motor - well I had been switching the headlamps on and off? The interior light and ignition lamp still worked so there must be some power.
Took the battery out and charged it overnight. Still no luck.
Clambered under the car and turned the starter motor by hand, still not luck.
Disconnected the starter motor power cable and the soleniod worked so assumed it must be a dodgy starter motor. Looked as if it was shorting the battery every time the ignition key was turned.
Jack the car up at the front and fight with the two bolts holding the starter motor in to remove it, phone round and source a replacement unit, drive 20 miles each way to collect the replacement started. Fit the replacement unit, connect the battery and turn the key... And yes, you guessed it, the same problem!!
Pull out all the wiring under the dash and check that there is no short. Short the solenoid terminals to check the starter, no luck, check voltage with meter at solenoid, 12.5V so that's OK.
Try to start a second starter motor (I had a old unit with a broken bendix) from the solenoid using a pair of jump leads, one side from the solenoid positive and the chassis, nothing.
Try directly across the battery, starter turns...Finally progress.
Try positive from battery and earthing to chassis/engine.. Nothing.
Try a second cable from the battery negative to the earthing point on the chassis near the petrol tank... Everything works.
Problem finally tracked down to a dirty connection between the battery earthing cable and the chassis (even thoug the connection was tight). Solution clean the terminal connector and reconnect.

Moral of this tale..
Just because your car was working 5 mins ago and you have been playing around with the electrics don't assume that the new electrical problem you now have was caused by you - it could easily be at the other end of the car!!
Just because you can measure a good voltage between the positive side of the starter solenoid and earth do not assume that you don't have any bad earth connections anywhere. The started draws a very high current so any bad earth in the circuit and the car will not start.
Elans can sometimes be easily (and cheaply fixed) assuming you don't buy parts you don't really need....
Check the simple things first before assuming the worst!!

Carl
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PostPost by: steveww » Mon Apr 25, 2005 9:19 am

Had a very similar problem with my Elan last year. I had just loaded the car up ready for the off to Le Mans. Stopped at the petrol station a few miles from my house to fuel up for the journey. Of course the starter would not turn when I went to leave the petrol station. Push started the car and drove home again. Check through all the starter electrics and found it was the battery cut off switch that had been nudged by the luggage. It was on but only just. Enough for the ignition circuit etc to work but not enough for the high current of the starter. Took me half an hour to find though :angry:
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PostPost by: dougweall » Mon Apr 25, 2005 7:33 pm

Guys,

I just wonder if this will help you avoid problems in the future.

I asked an electrician where I work what I could do to help overcome any potential problems with bad earth's during the rebuild of my elan. (He has rebuilt 3 1930's cars)

Anyway, his solution was for me to put in an earth wire linking all 4 chassis earth points. Starting at the driving side engine bay earth point, then the opposite side, then below the dash, and on to the boot point. this in a sense eliminates the chassis as an earth as it were, for all the minor electric's (2.5mm cable). Fastened it to the loom with cable ties.

Also to aid starting run a battery size cable from a starter motor bolt either direct to the battery earth or to the boot earth point.

I am halfway through the process of getting my car up and running again (with a new loom fitted) and even I was surprised at the brightness of the lights etc etc, I know you are saying well so they should be, but it was heartening to say the least, everything worked straight away. Hopefully this week, from the history I have gathered, I will be firing it up for the first time in 17 years so here's hoping all is well.

Hope the above is of some assistance.

Doug
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PostPost by: type26owner » Mon Apr 25, 2005 7:46 pm

Hey Carl,
A reading of 12.5 volts on the battery means it's condition is questionable. Good batteries have a minimum voltage reading of 12.6 after having been fully recharged and the surface charge removed. Between 12.6 and 12.4 volts the battery should be tested under load with a carbon pile to determine if it's still okay. A reading of 12.4 or below means the battery is shot and needs replacing. Don't get caught out with a failing battery. Just did this battery diagnostic stuff along with fully testing the alternator a couple of weeks ago on my son's car.
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PostPost by: poiuyt » Mon Apr 25, 2005 8:07 pm

Carl,

Glad you found the problem, but I have a question:

Why didn't you just get used to working the switch in the opposite direction, as long as everything else worked?

Steve B.
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PostPost by: gjz30075 » Mon Apr 25, 2005 10:11 pm

<!--QuoteBegin-poiuyt+Apr 25 2005, 04:07 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (poiuyt @ Apr 25 2005, 04:07 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin-->

Why didn't you just get used to working the switch in the opposite direction, as long as everything else worked?

[/quote]
Or turn the decal upside down on the column shroud? :lol: J/K

Good story.

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PostPost by: Frank Howard » Tue Apr 26, 2005 3:00 pm

Carl,

Speaking of the headlight high beam lever, it also contains a momentary flash function. That function on my U.S. spec. car was disabled I suppose for some governmental regulation reason. I hooked it up and it works fine. Does your "flash" or "momentary flash" work on you car, or is it disabled like mine was?

Frank Howard
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PostPost by: M100 » Wed Apr 27, 2005 7:24 am

<!--QuoteBegin-Frank Howard+Apr 26 2005, 03:00 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Frank Howard @ Apr 26 2005, 03:00 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> Speaking of the headlight high beam lever, it also contains a momentary flash function. That function on my U.S. spec. car was disabled I suppose for some governmental regulation reason. [/quote]
Are you sure it wasn't just electricity leaking out of a Lucas connector? :-)

The column flash facility is a bit of a waste of time unless you already have the headlights raised on the vacuum first.

The original UK spec wiring (maybe everywhere except the US?) also had a flasher fitted so that if you raised the headlights on the vacuum valve and didn't switch the lights on electrically at the switch then they would automatically start flashing at around the same rate as the turn indicators.
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PostPost by: pereirac » Wed Apr 27, 2005 9:15 pm

I would have left the headlamp switch the other way round but the 'main beam' warning lamp came on when the dipped headlamp was switched on!!
I also connected the flasher to my headlamps so that the headlamp flashed when it came up. It had also been disconnected when I bought the car- local regulations over here as well I think.

Carl
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