Author Topic: Electrical problem  (Read 4543 times)

Mark280SL

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Electrical problem
« on: July 14, 2012, 17:37:37 »
I seem to have an electrical problem with my 70 280SL.  I first noticed the dashboard light that comes on when you open the door flickering when I was driving the car, then eventually it stayed on continuously while driving.  I then noticed that when opening the door ( either door) engine not running the dash light comes on and I hear a sound the same as you would hear from the fuel pump when turning the key to prepare to start the car , closing the door will then stop the sound and the dash light goes out, again the car is not running when i observe that. The car starts and runs fine but the battery is no longer charging, I know this because the battery keeps going dead.  I have also noticed that if the car is running and the door is open and I turn the ignition off and remove the key the engine will continue to run until I close the door.

It would appear I obviously have a wiring problem or maybe the generator has just gone bad? but I'm not sure where to start.

**UPDATE** Gentlemen thank you for the pointers. It appears the rear sensor in the brake fluid reservoir went bad and is the cause of the problem. When I tried to buy a single sensor several online suppliers said they had them but many did not actually have them and it turned out you can't easily buy a single sensor at a reasonable price if at all from many suppliers. I found a seller on ebay that sold me the complete reservoir with both sensors included along with the caps etc for $109.97 with free shipping which was 50.00 less for the same ATE part then some other places so, it pays to shop around a bit. Thanks again to those who responded.
« Last Edit: August 03, 2012, 14:57:24 by Mark280SL »
Mark

Cees Klumper

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Re: Electrical problem
« Reply #1 on: July 14, 2012, 17:42:20 »
Hi Mark - search the forum and others do chime in, but I seem to remember something about the low brake fluid warning circuit being able to cause symptoms like this. Also, electrical gremlins like this can be caused by bad ground /earth. If the battery is not charging check the ground cable; I would check as many grounds as I could identify.
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
1983 Porsche 944 2.5
1990 Ford Bronco II

Jonny B

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Re: Electrical problem
« Reply #2 on: July 15, 2012, 15:14:54 »
Try searching "door open light" you should find a number of threads to help explain this bit of an oddity about the set up on the 280 SL.
Jonny B
1967 250 SL Auto, DB 568
1970 280 SL Auto, DB 904
1966 Morris Mini Minor

glenn

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Re: Electrical problem
« Reply #3 on: July 21, 2012, 19:53:28 »
Is this the infamous 'low brake fluid level' problem????   Raise the contacts and see what happens.....

Garry

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Re: Electrical problem
« Reply #4 on: July 21, 2012, 23:13:31 »
It certainly sounds like the problem.

 Open your brake fluid reservoir and take out the float and see if it has fluid in it from a pin hole.  When it drops below a certain level it will cause the light to come on but it also causes the petrol pump to go when you open the door when the car is not on.  A quirk of the Pagoda.

Garry
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Melbourne/ Kyneton, Brisbane. Australia
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