Author Topic: Electrical Gremlin  (Read 5858 times)

Rocket

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Electrical Gremlin
« on: March 30, 2006, 12:54:14 »
When I operate the left hand turn signal this also flashes front fogs lamps and blows fuse! Righthand turn signal operates fine.

Also turning on sidelights - rears work fine, front left fine, but right front parking light on instead of sidelight! Turn righthand parking lights on -  rear light fine but front right side light comes on instead of parking light.

I ought to point out that I have recently rebuilt the car, but I am sure that the turn lights worked okay at first. The headlamp units seemed to be wired fine, but I am wondering whether there is a fault on the column switch somewhere.

Any suggestions?

Rocket


230SL 1965

jeffc280sl

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Re: Electrical Gremlin
« Reply #1 on: March 30, 2006, 14:52:35 »
Rocket,

Which fuse blows when you turn on the left blinker? Report back this info and we can go from there.

BACKGROUNG INFO: All front left lamps share a common ground, same goes for the right side.  I believe the ground is located in the head light bucket.  The positive fog light circuit should be completely independant of the turn signal and parking light wiring.  Wiring diagrams show the plus side of the right and left fog lights connecting directly to the main rotary light switch.  As you know there is a crossed wire somewhere. Do you have an ohm meter?  

For problem #2 the plus side of the side light and parking light are crossed.  Did you split apart the wiring block connected to the right side head light?  If so you may simply have crossed these wires when reassembling the connector.  It's easy to do.  If you had a DC volt meter you could disconnect the connector and and see which wire has +12V when the side light switch is on.  Do the same for the right parking light.  Once you have determined the correct pin try and reverse them in the connector block location and see if that solves the problem.



Jeff C.
1970 280SL 4-speed

Rocket

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Re: Electrical Gremlin
« Reply #2 on: March 30, 2006, 15:39:49 »
Jeff.

Thanks for your suggestions so far. Fuse 5 blows.

As you say there is a common ground connecting the wiring loom to  headlamp bucket but should there also be a ground from the bucket to the headlamp assembly in addition to the brown ground wire within in the main plug? I have subsequently checked with a volt meter and infact with the left blinker on the flasher unit is flashing side light, fog lamp and parking light terminals within the main connector plug (headlamp disconnected). I don't know where to go from here. I do have an ohm meter if you can help point me in the right direction.

Its almost midnight here, so I will check the block connector as you suggest tomorrow for parking/sidelight mix up. The plug may well have come apart at some point.

Incidentially all other lights and other electricals work correctly other than those already mentioned.

Rocket

230SL 1965

jeffc280sl

  • Guest
Re: Electrical Gremlin
« Reply #3 on: March 30, 2006, 17:14:08 »
I'm not sure what you mean by headlamp assembly.  If you are referring to the assembly that includes the chrome frame, plastic lamp surround and blinker lamps I would say no.  The lamps themselves are grounded via the connector and brown wire secured to the bucket.

When you say flasher unit I assume you are referring to the stalk on the steering column.  So when you turn on the left blinker using the steering column stalk the side, fog and parking lights circuits have +12V on and  off with the main connector disconnected.  If the connector is disconnected you blow fuse 5.  Is this correct?  

[Side note:  Some stalks have a head light flash enabled.  This is similar to modern cars where you pull the stalk towards the steering wheel and the headlights turn on.  Release the stalk and the headlights go off.  On later SL's like mine the stalk is capable of the function but the wire was not installed so this function was not enabled.  I and many others have added the wire and enabled the flash to pass function.]

Jeff C.
1970 280SL 4-speed

Rocket

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Re: Electrical Gremlin
« Reply #4 on: April 01, 2006, 14:17:41 »
Jeff,

Thanks for your suggestion ref mixed up wiring, as this is all the problem was. The ground/flasher terminals in the connector block where reversed, ditto on with the parking light/side light on the other headlamp. I did remove the wiring loom about 5 years ago, and it must have come apart then and I incorrectly reconnected. Hey I can't remember what I did last night, let alone 5 years ago!

My headlamp flasher (flash to pass function I think you guys call it), is the only outstanding electrical glitch, and I am sure this used to work before I dismantled the car. How can I get this going?

Rocket

230SL 1965

jeffc280sl

  • Guest
Re: Electrical Gremlin
« Reply #5 on: April 01, 2006, 18:12:27 »
Great news Rocket!  Glad to help.  Search under "flash to pass" or "headlight flash" and you should find plenty of info.  As I recall the stalk switch is wired for this function.  The connector block which mates with the stalk block is missing a wire so the factory could disable the flash to pass function for the US market.

Jeff C.
1970 280SL 4-speed

rwmastel

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Re: Electrical Gremlin
« Reply #6 on: April 04, 2006, 15:59:56 »
quote:
Originally posted by jeffc280sl

As I recall the stalk switch is wired for this function.
I think the USA cars had a wire disconnected to stop this function.  As said, use the Search tool to find the answer on these issues.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420
Rodd

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