[andy bev]

Hi guys from Andrew from over the pond.

This forum seems to be the best place for info on my recently bought 1984 280 sl. Firstly, when i put the headlights on dip about every 10 seconds or so the main beam lights flash, very strange, I have no instrument lights and the clock doesnt work, all the fuses seem to be ok. second, the heater control on the right hand side doesnt work, it only slides down about half way and doesnt operate any thing ( non air con ), so its blowing hot air all the time. Any help would be much appreciated.

I will post some pics if ever it stops raining here in Yorkshire

Thanks Andrew

 

[rowdie]

Welcome to the asylum.
Check the EGv107 Sticky. Scroll down to the Climate Control section. Excellent write up of the lever system by Aussiemerc. http://www.benzworld.org/forums/r-c...lopaedia-germanica-volume-107-aka-egv107.html

There is also a post on repairing your clock in another section.

Dash lights. Try rotating the dimmer switch on the cluster back and forth a hundred times or more. The contacts on the potentiometer get corroded. Many have brought theirs back to life by doing this.

 

[petesmga]

^^ + 1 What he said. Also add a ground wire to the back of the instrument cluster, been known to fix many odd problems.

 

[Digmenow]

...Dash lights. Try rotating the dimmer switch on the cluster back and forth a hundred times or more. The contacts on the potentiometer get corroded. Many have brought theirs back to life by doing this.

Maybe even 200 times. Don't give up.


And then you might have to do it again another year or so from now.

 

[hchaugli]

Heating blow hot air:
This could be a corroded monovalve which fails open. It is located just behind the battery, easy acces and repair kits are not expensive.

Flashing headlight:
Could be light cables shorting as you pass bumps, remove footwell kick panel and wiggle the cable to reproduce the flash. Could also be elsewhere in the wirng loom.
Your light switch could be worn, again wiggle it to reproduce the problem.

 

[Aussiemerc]

Levers/heat

If your heater valve looks like this the default position is open so if it fails you get heat.
However it sounds like you have a lever adjustment problem.

 

[andy bev]

Thanks for the replys guys, I now have sore fingers but I do have instument lights, nice one.

Will check on the heater valve later today. And as far as the clock goes i think I'll wear my watch, too big a job for me.

 

[Aussiemerc]

Clock

And as far as the clock goes i think I'll wear my watch, too big a job for me.

Nah! The strained muscles (getting steering wheel off), scratches on back of hand (getting cluster out )and burns from the soldering (clock repair) will all heal and think of the satisfaction of fixing it for less than $5 !
Then there's all the other stuff you might discover.

 

[Pex]

I also had problems with the heating on my 280SL -85...
Have some pictures here...
http://www.benzworld.org/forums/r-c107-sl-slc-class/1614599-my-climate-control-acting-wierd-heat.html

 

[redghost]

From the two hose to the one vac connection, which line, RED or GREEN? My OE pot is in failure mode, but I am able to manually close it from under the hood. When I swap in the new pot, I want to hook the proper line up.

 

[Aussiemerc]

From the two hose to the one vac connection, which line, RED or GREEN? My OE pot is in failure mode, but I am able to manually close it from under the hood. When I swap in the new pot, I want to hook the proper line up.

The vac diagram with colors is in the manual . I think your valve is different to mine.

 

[rowdie]

From the two hose to the one vac connection, which line, RED or GREEN? My OE pot is in failure mode, but I am able to manually close it from under the hood. When I swap in the new pot, I want to hook the proper line up.

I don't remember anyone that has done it reporting back on which hose was used to make it function properly. You have a 50-50 chance of getting it right the first time.

Edit: Just so there is no confusion. The early model redghost has was equipped with a dual action vacuum element with two lines. The heater valve was a separate metal unit controlled by the element. The newer one piece plastic model with one line is used to replace both parts.

 

[Aussiemerc]

My single valve has a red line to it.

 

[redghost]

That is what I thought. I have seen a few cars that had the swap using the green line, but the drivers all complain of wonky heat. I have the original valve still installed and the vac is not holding or somehow it only allows the valve to open, but not close again.

I have a pair of the black replacement valves, they test well, so will install one in the coming weeks so that I can control the heat. Right now, I either freeze on the road, or feel like a large turkey being roasted for Thanksgiving dinner. As long as it is not raining, I can drive with the top down.

 

[petesmga]

A PO didn't bother to track down the vacuum problem and installed a "choke cable" to operate the valve. I fixed the vacuum but prefer the manual cable as I can regulate the heat better.

 

[andy bev]

If your heater valve looks like this the default position is open so if it fails you get heat.
However it sounds like you have a lever adjustment problem.

So if i wedge it closed I will get no heat ??

 

[rowdie]

So if i wedge it closed I will get no heat ??

Assuming the closing piece is not broken internally, yes.

 

[Aussiemerc]

If it is broken you could pinch off the water hoses in and out as a temporary measure.

 

[masand68]

I have the old style, valve and vacuum element are two separate pieces.

If I replace these with the newer style 1 piece valve/element, how do I connect the vacuum? 1 line gets connected and do what with the other? Just plug it?
Also, can the valve be replaced from the firewall or do I need access to the backside as well?


Sent from AutoGuide.com Free App

 

[rowdie]

Yes just plug one supply hose. The green one I think. Remove the blower motor cover to get to the rear hose connection.