Electric fan conversion

[Merc_Girl]

Hi folks

Does anyone know if an electric fan conversion is available for a 230SL?

Hank you

Katie


EDIT:  Changed "lconversion" to "conversion" in thread topic. - rwmastel

[mdsalemi]

Katie, you may have to search a bit, using the search function. I think this has been discussed in the past.

The usual discussion has to do with solving a cooling issue, and if that's your problem, it may be useful to check out all the solutions including new or re-cored radiators, oil coolers, etc.

Dan Caron (Dr. Benz) has always suggested that a good deal of the engine's cooling is done by the oil, so an oil cooler isn't bad.

I don't have a 230SL but when I first got my 280SL back from restoration (in which the radiator was re-cored locally) it didn't like stop and go traffic nor slow driving in the heat of a sunny summer day. Some years later I had the radiator professionally re-cored through Gernold Nisius at SL Tech in Maine, USA. Not necessarily an option for you, but maybe the local folks (like Colin Ferns) can work with you.

Once I got the radiator back from Gernold my cooling woes were gone.

[rwmastel]

Katie, you may have to search a bit, using the search function. I think this has been discussed in the past.

Very recent past. 

EDIT:  Found it for you.   
https://www.sl113.org/forums/index.php?topic=36788.0

[Merc_Girl]

Hiya
Thanks for prompt response!!

So currently, no issue with overheating, thank goodness

The question arose as I went to a company that specialise in electronic air con, don’t ask me the difference, haven’t a clue!!

Anyway, their first idea was to put the cooler thing, needed for the air con, in front of the radiator, which obviously reduces airflow and increases chances of overheating when stuck in traffic and engine on idle. He was therefore asking if an electrical conversion was available, hence reaching out to this knowledgeable group 😁

[Alf]

I have a switchable ancillary electric fan fitted between the radiator and the star grille. The viscous coupled one is still in operation so this just provides extra air flow. I use it only in bursts as needed. A godsend when stuck in slow moving city traffic in the summer or at queues that can form at Italian Autostrada toll plazas! Roger Edwards fitted mine

[rwmastel]

Anyway, their first idea was to put the cooler thing, needed for the air con, in front of the radiator, which obviously reduces airflow and increases chances of overheating when stuck in traffic and engine on idle. He was therefore asking if an electrical conversion was available, hence reaching out to this knowledgeable group 😁

I have a switchable ancillary electric fan fitted between the radiator and the star grille.

Alf,  This is where the company wants to put an A/C "cooler thing".  I think she's looking for a better fan solution for behind the radiator.  Some of that was discussed in the thread I posted, but there are many other threads to be found about electric fan conversions.

[franjo_66]

Hiya
Thanks for prompt response!!

So currently, no issue with overheating, thank goodness

The question arose as I went to a company that specialise in electronic air con, don’t ask me the difference, haven’t a clue!!

Anyway, their first idea was to put the cooler thing, needed for the air con, in front of the radiator, which obviously reduces airflow and increases chances of overheating when stuck in traffic and engine on idle. He was therefore asking if an electrical conversion was available, hence reaching out to this knowledgeable group 😁

I think they are talking about the condensor, which normally does reside in front of radiator. They may want to add electric fans in front of the condensor to help with airflow & cooling

[mdsalemi]

There is a company in the UK, called classic retrofit, that makes electric air conditioning systems, bespoke, for Porsches.

Just out of curiosity in addressing the question here I went and investigated a little bit. Turns out that their electric compressor requires 35 to 50 amps by itself. I think that means you need to double the size and capacity of the alternator in the Pagoda in order to have enough power to run it properly. I ask the question of others— is that even possible? What advantage are you buying over a belt driven compressor? Our old cars and in fact, any old cars require a bit of electricity to run. Does any car by itself have a spare 50 amps of capacity?

[Merc_Girl]

Yes, these were the folks I went to see. They are very knowledgeable and they had been thinking g of doing a ‘kit’ for Pagodas.

They laughed, saying everything was very ‘Germanic’, ie over engineered!

So, they weren’t happy that sufficient air could be pulled through , yes now you mention it it was the condenser, when engine on idle and therefore overheating may be an issue when stuck in traffic. So it was they who asked as to whether I knew if the was an electric fan conversion kit. Hence the question.
I don’t think I can put an auxiliary fan in front of the radiator as that is where the condenser will go
Their alternative was to put a small condenser, with a fan attached, under the rear offside panel, tucked in between the wing and the spare wheel (Bessie has the vertically mounted spare in the boot)

[teahead]

YOu can definitely add an auxiliary fan in front of the condensor and have it only come on when the AC Clutch compressor engages.

[Raymond]

My 280SL has a second condenser behind the front bumper. 
There is very little room between the main condenser and the back of the star.  I think it would be visible from the front. 
The "High Output" alternator is 55 amps, so it would be tough to spare 50 amps for an electric AC. 

[lpeterssen]

The proper path in a case like that is to modify the main harness, and bump its capacity up to handle more power.  Is a good opportunity to have a custom wiring harness that eliminates all erratic gremlins plus adding that room for expansion.

I have done that many many times in all the wiring restorations works I have performed so far.

Even for that electrically driven ac system a dedicated ac wiring harness will be advisable.  The condenser fans should be triggered only when the high pressure refrigerant gas setting is reached inside the cooling system, not every time the compressor engages as is the laziest solution most people take.  Some more control logic is needed on the long path that I suggest but that will provide a more comfortable ride and less stress over the electrical system. 

When you are cruising and have plenty of wind passing through condenser there is no need to trigger the electrical fan; even though the compressor may be engaged at that time.

I just delivered a week ago a w113-230SL harness with all those goodies.


https://www.icloud.com/sharedalbum/#B0QGZYbYHGzb58h

See this album

Best regards
Eng. Leonardo Peterssen

[lpeterssen]

The cubic kind of relays will be installed above the footwell in the cabin, so will be out of regular sight. Those are the ones responsible of the ac logic.

On the engine bay, everything will look original as it came out of factory, no additional components installed there, beside the ones that came with the pagoda.

[lpeterssen]

On this project the following important decision were taken to accommodate the ac system

1. Charging and electricity capacity
of the main loom was brought from original 4+4 mm2 section to 10+10 mm2.  10mm2 to the starter branch which at the ends goes directly for charging the battery, and the other 10mm2 section went to the main light switch, which as you know acts like an energy hub on the pagodas.

2. Ignition switch.
T30 feed line from main light switch to ignition tumbler was brought from 1x line  2.5mm2 to two lines with 4mm2.  For a total of 8mm2. That made me change the original tumbler switch which had eyelet terminals to the latest model used on 280SL which has plug in round Bakelite connector.   This later model has two pins for T30 signals and 2 pins for T15 signals.

3. Main fuse box
T15 feed line to energize all circuits except the illumination (exterior lights related) was changed from 2.5 mm2 to two lines with a total of 8mm2.

4. Auxiliary fuse box for ac system.
The auxiliary fuse box for the ac system is installed on the engine bay on the position where usually goes the radio/power antena fuse box.  This later one was relocated inside cabin.  Or can be kept there if you wish.  The auxiliary ac system fuse box has only two ports. One for the main ac console (evaporator) and another for the condenser auxiliary electric fan.

5. AC Dryer/desiccant should be installed as per original Mercedes Pagoda ac system booklet on the firewall next to the wiper motor on LHD cars. There, on that canister a pressure switch will be installed to govern the relays that are installed inside cabin on the upper part of the driver footwell (not visible).

6. Relays arrangement.  Cubed relays to control ac system on driver footwell.  The selection of this kind of relays is because of its reliability, size, and mounting options.  And also because they are original to later mercedes.


Well there are many other details, but this is to give you an idea of what I consider the best path to take if installing an ac system on a pagoda.

Best regards
L.Peterssen

[lpeterssen]

Another comment

Modern ac systems with electrically driven compressor or with regular pulley driven compressor use R134a as the refrigerant gas.

This gas has different properties compared to R12 which was used on the times the MB was built.

Therefore a new AC system using this kind of gas can not be installed exactly as per original MB Pagoda manual written on that era.

R134 running system requires aluminium condensers to increase heat exchange per square feet and also electrical fans to run a lot of air through them.

That last sentence is critical on realizing that a modern ac system requires much more electrical power to work than the R12 system described on the pagodas original manual.

Therefore the electrical system of the pagoda as IT IS ORIGINAL is not in the capacity of handling those new loads.

Best regards
L.peterssen

[lpeterssen]

I think that this topic would be a good candidate to the RESEARCH AND DEVELOPMENT section or either the traditional ELECTRICAL and instrumentation…..

[Merc_Girl]

True. Not sure how to move though 😔

[ctaylor738]

"2. Ignition switch.
T30 feed line from main light switch to ignition tumbler was brought from 1x line  2.5mm2 to two lines with 4mm2.  For a total of 8mm2. That made me change the original tumbler switch which had eyelet terminals to the latest model used on 280SL which has plug in round Bakelite connector.   This later model has two pins for T30 signals and 2 pins for T15 signals."

Excellent write-up by Leonardo, but I think it would be better to use the ignition switch as the 86 circuit for the relay, and avoid running 30 circuit through the ignition switch.

Cheers,

CT

[lpeterssen]

Dear Taylor

Good suggestion, to use the ignition tumbler just as a triggering device to activate a relay responsible of bringing power to all T 15 circuits.

Nevertheless the solution implemented does not exceed ignition tumbler total capacity as this same part in exactly the same configuration is being used by mercedes w108 later models with V8 engines (3.5 and 4.5 liters).  In those cars a total of 12mm2 pases through the two T30 lines and 8 mm2 through the T15 ports. 

So the solution implemented is inside range.

If it were my own car, I will go for your solution since a damaged relay is much cheaper to replace than an ignition tumbler switch, but for other MB owners who are more look oriented I always try to minimize the use of additional components.

Best regards
Lp