Electrical signal when car stops - Page 2 - PeachParts Mercedes-Benz Forum

quickster · #16 02-09-2011, 10:26 PM

Quote:

Originally Posted by Dr_SJH

So here are two relays that monitor throttle position. What do both of them do?

Thanks

I would also like to know what these two switches do. One of the wheels on the switch in my car must have been stuck for a while because it has a flat spot worn into it now, along with a groove in the plastic. Are they transmission related?

sjh · #17 02-10-2011, 12:14 AM

Quote:

Originally Posted by Jeremy5848

My 1989 "Service Manual/Automatic Climate Control/Model 124" says that there are only two choices for recirculation: 80% or 100%. Your 1990 might be different, I suppose. Unfortunately, in this part of this manual the English translation is ambiguous. One thing it does say is that the system tends to use more recycled air if it is very hot or very cold outside. That makes sense - less work for the system. The manual is very clear that when you press S24 (the recirculated air switch in the row above the PBU) you get 100% recirculated air.

As an unhelpful suggestion, I will note that our 1996 E300D has a carbon filter as part of its climate control system and it works well. Caveat: the aftermarket replacements are not very good; the factory carbon filter, expensive as it may be, is the one to get. BTW, I don't think it is possible to retrofit one to a 124.

Jeremy

Yes to all the above.

To the best of my memory when I pulled my dash and did the pods I spent time with the mity-vac and I thought my direct measurements on my car are what makes me think 100% only occurs upon shut-off. But I could easily be wrong.

My E430 had the activated carbon filters. Very nice. I had started a small business about 2 years ago using gaseous chlorine dioxide to deodorize and disinfect interior spaces. My past year struggle with cancer has side-tracked me but one of the commodities I have purchased is 50 pounds of granulated activated charcoal that has also been treated with a proprietary component (I believe it is primarily potassium permanganate) and use that in a high volume fan system to rapidly remove any residual gas or irritants.

Long story made short. I have 30 pounds or so of very effective activated charcoal designed for purifying breathing air. I am pursuing an easy means of inserting a canister (whether metallic or fabric) into the w124 ventilation system. So are thoughts have similarities.

jt20 · #18 02-10-2011, 01:15 AM

what about the brake light switch?

Or, if you are good with electronics, you could use an accelerometer.... pos=open, neg=re-circ

compress ignite · #19 02-10-2011, 01:31 AM

EGR

sjh · #20 02-10-2011, 08:02 AM

Quote:

Originally Posted by compress ignite

EGR

Both?

Since I've performed gsxr's wastegate conversion are they no longer necessary?

Jeremy5848 · #21 02-10-2011, 11:42 AM

You could make a stand-alone filter with a 12V fan and your charcoal, put it in the passenger footwell, plug into lighter socket. Crude but workable.

lutzTD · #22 02-10-2011, 12:34 PM

Quote:

Originally Posted by jt20

what about the brake light switch?

Or, if you are good with electronics, you could use an accelerometer.... pos=open, neg=re-circ

I second the brake light solution, maybe add some sort of delay but the brake will almost always be activated when stopped unless you idle in park a lot. A delay can be as simple as adding a orifice to the vacuum pod on the recirc, which it may already have anyway

sjh · #23 02-10-2011, 05:42 PM

Quote:

Originally Posted by Jeremy5848

You could make a stand-alone filter with a 12V fan and your charcoal, put it in the passenger footwell, plug into lighter socket. Crude but workable.

When my chemical sensitivity was at its worst I drove from Texas to San Fran.

I had purchased a HEPA Filter/Activated carbon air purifier for my house.

It ran off of house current, was about 3 feet tall and maybe 18" in diameter.

For the drive I put a 110 VAC inverter in the car and placed the HEPA unit in the passenger compartment. It ran continuously for the drive. Worked well.

Having just done the pods and so having taken everything apart and knowing the layout I think I can pretty easily put a canister in the existing system.

sjh · #24 02-10-2011, 05:47 PM

Quote:

Originally Posted by lutzTD

I second the brake light solution, maybe add some sort of delay but the brake will almost always be activated when stopped unless you idle in park a lot. A delay can be as simple as adding a orifice to the vacuum pod on the recirc, which it may already have anyway

I think the Hall device is best but as I say I am a chemical and material science guy. My electronic skills are modest.

One other point. The vac pods run at reduced pressure. When the signal is sent to a pod to change it takes time for that to occur. So a pod may be given three different commands over a brief period but actually move a small amount.

I expect I will have the unit default to the recirc mode. I'll use the microswitch that tells when the throttle is at rest and timer with a delay somewhere between 30 secs and 5 minutes.

After whatever delay I chose, if the throttle is not at rest, the recrc will shut-off.

I'll try to build it in the next two weeks.

Thanks to everyone.