Gasoline Shower, Best Avoided

When you remove the fuel pumps from a 560 SEC, you have the opportunity to have a gasoline shower, with the fuel running down your arm and thoroughly soaking you, clothing and all.  I don’t recommend you pursue this particular style of self-destruction.

IMAG8728The alternative I choose is to jack up the passenger side rear wheel, way high, and to place an axle stand under the suspension component close to the wheel.  Then, I place a container underneath the fuel pumps, and then slightly loosen a connection so that the fuel drips into the container, thus emptying the tank.  That way, I don’t have to deal with as much of a gasoline mess, when you take the pumps out. There will still be some gasoline and pressure, but it’ll be a better situation than if the tank contained a large amount of gasoline.

I suspect that I could also have used the drain plug at the bottom of the tank, but draining it at the hose I’m supposed to work with tends to make that critical area better-drained.

Gasoline and static electricity tend to make for a big fire. And, gasoline being drained does, according to one story I’ve read, build up a static charge that can trigger a static spark that can burn down a building.  So, I ground the car with a steel cable from the negative battery post to the floor.

No-Start True Story About Dead Fuel Pump

I recently bought a lovely 1988 Mercedes-Benz 560 SEC from a nice gentleman. The car had been sitting for years. The fuel distributor was so gunked-up that when I jabbed at the air flow plate with my finger, the plate stayed in whatever position I left it at. It’s supposed to bounce back.

Even with fuel in the tank, and a good battery, and compression, and spark, the car wouldn’t start, even though it cranked over nicely.

I wanted to rule out the fuel distributor. I could hypothetically remove it and soak it in solvent, but instead I got another unit from another 560 SEC, and I cleaned that and installed it.

IMAG8604

Still … no start. These cars are relatively simple as to fuel delivery. The “E” in Bosch KE Jetronic means that the fuel distributor optimizes the mix based on electrical input, but even without that, it basically works — mechanically, and for that it needs fuel pressure. To be precise: it needs A LOT of fuel pressure. It expects the fuel pumps to deliver more than 84 psi, and then a regulator right by the fuel distributor limits that to 84 psi. That’s very high, about double what a BMW of the same era would run, as fuel pressure.

To generate that much pressure, the car uses two fuel pumps, in series. When I cranked the motor, both fuel pumps got power, and there was the sort of hissing sound you’d expect from a functioning-fuel-pump situation. Still, no start. So, I suspected one of the fuel pumps was bad.

I removed the cradle in which the fuel pumps are housed, and tested each one individually. Sure enough … one was bad. That explains the no-start situation. We replaced the bad pump with a good used pump, and did a pressure test. Together, the pumps put out more than 84 psi. Yay! So, now they are ready to go back into the car — and now I suspect it will start.

I want Empathy when I Buy Parts, Dammit

New-parts counter guys for exotic cars have a rough life. I can guess why. Day after day, he deals with the following two sorts of dialog, many times a day:

“Hey, I’m looking for a fuel distributor for a 1986 560 SEC.”
“What’s the VIN?”
“I don’t know. I don’t have it with me. I’m at work. The car’s at home.”
“I need the VIN to look up the parts.”
“Seriously?”
“Yes.”
“Well, I don’t have it.”
… and it doesn’t get better after that.

Assuming the person does have the VIN, the next conversation goes something like this:

“How much for the fuel distributor?”
“$714.34.”
“Say, what?”
“$714.34.”
“For the fuel distributor?!”
“Yes.”
“Wow! The entire car cost me maybe $3K and that had a working fuel distributor. That’s crazy.”
… and it doesn’t get better after that.

Aftermarket prices are often better, and sometimes not by much. Sometimes, when I heard the price, I thought “Forget that,” or some less-polite variant.

Seems to me that whoever comes up with these prices has no idea of the basic viability of someone who’s not made of money, trying to keep their 126 Series car. There seems to be a basic disconnect when the parts prices are so high that a customer reacts with incredulity. Basically, the vendor and the customer don’t relate to each other. They’re are not on the same page. There’s no empathy.

* * *

New Mercedes-Benz parts prices can suck, but there’s a parallel to that: software.

How often have you used software that sucks, because regardless of how technically cool it might be, it sucks for you because it doesn’t work for you? Whoever made it didn’t empathize. As to whatever your situation was, they didn’t “get it.”

There is a better way. In the software industry, it’s called “Eat your own dog food.” Wikipedia defines it as: Eating your own dog food, also called dogfooding, is a slang term used to reference a scenario in which a company (usually, a computer software company) uses its own product to demonstrate the quality and capabilities of the product.”

It’s a great idea.

That might be the best reason to buy your used parts from my little company. What’s in it for you? You’re understood. That’s it. We also drive old 126 series cars and we’re trying to keep them going, with a tight budget. We empathize.

For a while, I’ve driven a 1986 560 SEC whose engine was leaking coolant. And, I survived. I didn’t have money for the “new parts” solution. I just kept pouring in coolant, before every trip.

My little used parts business is not the world’s smartest when it comes to 126 series cars. We haven’t been in business the longest. We don’t have massive depths of technical insight. We don’t have a huge inventory. We often mis-estimate the time it’ll take to get a part into inventory.

But, dammit, we relate. We have our own little sad fleet of several floundering old 126 series cars, and we struggle to keep them going on a tight budget that includes wondering how we’re gonna pay the rent this month. We get personally stranded when a main fuel pump dies, and we have to walk home and figure out what’s wrong, how to remove the bad part without causing a fire, and how to replace it without paying three figures.

This struggle makes us relate to customers who struggle, just like us.

We need to buy food, pay the rent and somehow keep viable, as transportation, an almost-30-year old car that most people have given up on, long ago.

We tenaciously refuse to let these cars die. We make plans, we find money, and we pull through — so that we can keep driving these magnificent pieces of engineering, even if the dash lights don’t work and the heater fan is broken. At some point the way we’d start one the company 560 SEC cars was to hot-wire the fuel pump. But, dammit, we kept it going until we could figure out a better way. We’re still in the game. We’re fighting and if driving the car one more day is victory, then we’re winning.

If you like that mindset, buy your stuff from 126seriesparts.com because you’re dealing with someone who “gets” you.

Relay 201 821 00 47 for the W126 Series (1986-1991) Mercedes-Benz 560 SEC

Relay (for indicator lights, hazard lights, wipers, etc.) 201 821 00 47 for the W126 Series (1986, 1987, 1988, 1989, 1990, 1991) Mercedes-Benz 560 SEC
Part number 201 821 00 47 belongs to the relay for the indicator lights, hazard lights, wipers, etc. for the W126 Series (1986, 1987, 1988, 1989, 1990, 1991) Mercedes-Benz 560 SEC.

imag4816We guarantee that this part will fit this model.

We are offering this part (number 201 821 00 47) used and guaranteed, for $40.

  • Please add $15 for shipping to anywhere in the US.
  • Nevada residents, please add 30 cents (which is 7.6%) for sales tax.

Our parts are used but original Mercedes-Benz quality, guaranteed to fit and work, otherwise (your choice):

  • We replace it at no charge or
  • We refund your money and the shipping costs to you and back to us.

Below is a little write-up that we hope you will enjoy — one more reason to be enthused about keeping your Mercedes-Benz on the road. You could buy the parts from a vendor who doesn’t understand or care about Mercedes-Benz cars, or you could buy from enthusiasts like us. We hope you choose us!


To remove the part, you normally don’t need any tools (how nice is that?) First, look at the above picture to see how the pins look. Then grasp the module firmly but gently, and slowly wiggle the module back and forth, to “walk” the little pins loose. Then, lift up the module and move it up and away from the general area.

If it’s stuck, resist the temptation to yank it hard. Either keep patiently wiggling it, or work a screwdriver or dull knife under the edge of the relay to pry it up.

To install the replacement, make sure the pins are aligned correctly, and then gently place the module in position and push down until you feel that it is seated.


This should help dispel the myth about Mercedes-Benz vehicles being overly complex. Yes, the internal functionality is complex, and necessarily so, but Mercedes-Benz has made that nicely modularized, and the part is so exceedingly easy to remove and to install that you require no specialized tools or knowledge. That’s about as simple and easy as something like this can be.


In software design, modularization is good. The same is often true for electrical circuit design. Mercedes-Benz seems to be exemplary. Rather than spreading the complexities of the turn signals, hazards, wipers, rear defroster and trailer hook-up across a massively complex wiring harness, Mercedes-Benz consolidated it into one nice module that’s easy to remove and to install. It’s typically in the engine compartment on the driver’s side, close to the firewall, or inside the (nicely protected) fuse box. The functionality and design of this particular module have been so universally applicable that it was used in many models in the W126 series, the 1979 – 1991 S class, over many years.

This standardization reduces the production costs as well as inventory costs for the factory and repair shops.

This means the money for purchasing and servicing your Mercedes-Benz goes more to aspects that add value and less to inefficiencies.

Relay 201 821 00 47 for the Mercedes-Benz SEL and SEC Models in the W126 Series

Relay (for indicator lights, hazard lights, wipers, etc.) 201 821 00 47 for the Mercedes-Benz SEL and SEC Models in the W126 Series
Part number 201 821 00 47 belongs to the relay for the indicator lights, hazard lights, wipers, etc. for the Mercedes-Benz SEL and SEC Models in the W126 Series.

We guarantee that this part will fit the following models in the 1979 – 1991 Mercedes-Benz S Class a.k.a. W126 Series:

  • The following four-door models:
    • 300 SD (1980, 1981, 1982, 1983, 1984, 1985)
    • 300 SDL (1986, 1987)
    • 300 SE (1985, 1986, 1987, 1988, 1989, 1990, 1991)
    • 300 SEL (1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993)
    • 350 SD (1991)
    • 350 SD (1990, 1991)
    • 380 SE (1979, 1980, 1981, 1982, 1983, 1984, 1985)
    • 380 SEL (1979, 1980, 1981, 1982, 1983, 1984, 1985)
    • 420 SEL (1985, 1986, 1987, 1988, 1989, 1990, 1991)
    • 500 SEL (1980, 1981, 1982, 1983, 1984, 1985)
    • 560 SEL (1985, 1986, 1987, 1988, 1989, 1990, 1991)
  • The following two-door models:
    • 380 SEC (1981, 1982, 1983, 1984, 1985)
    • 500 SEC (1980, 1981, 1982, 1983, 1984, 1985)
    • 560 SEC (1985, 1986, 1987, 1988, 1989, 1990, 1991)

We are offering this part (number 201 821 00 47) used and guaranteed, for $40.

  • Please add $15 for shipping to anywhere in the US.
  • Nevada residents, please add 30 cents (which is 7.6%) for sales tax.

Our parts are used but original Mercedes-Benz quality, guaranteed to fit and work, otherwise (your choice):

  • We replace it at no charge or
  • We refund your money and the shipping costs to you and back to us.

Below is a little write-up that we hope you will enjoy — one more reason to be enthused about keeping your Mercedes-Benz on the road. You could buy the parts from a vendor who doesn’t understand or care about Mercedes-Benz cars, or you could buy from enthusiasts like us. We hope you choose us!


To remove the part, you normally don’t need any tools (how nice is that?) First, look at the above picture to see how the pins look. Then grasp the module firmly but gently, and slowly wiggle the module back and forth, to “walk” the little pins loose. Then, lift up the module and move it up and away from the general area.

If it’s stuck, resist the temptation to yank it hard. Either keep patiently wiggling it, or work a screwdriver or dull knife under the edge of the relay to pry it up.

To install the replacement, make sure the pins are aligned correctly, and then gently place the module in position and push down until you feel that it is seated.


This should help dispel the myth about Mercedes-Benz vehicles being overly complex. Yes, the internal functionality is complex, and necessarily so, but Mercedes-Benz has made that nicely modularized, and the part is so exceedingly easy to remove and to install that you require no specialized tools or knowledge. That’s about as simple and easy as something like this can be.


In software design, modularization is good. The same is often true for electrical circuit design. Mercedes-Benz seems to be exemplary. Rather than spreading the complexities of the turn signals, hazards, wipers, rear defroster and trailer hook-up across a massively complex wiring harness, Mercedes-Benz consolidated it into one nice module that’s easy to remove and to install. It’s typically in the engine compartment on the driver’s side, close to the firewall, or inside the (nicely protected) fuse box. The functionality and design of this particular module have been so universally applicable that it was used in many models in the W126 series, the 1979 – 1991 S class, over many years.

This standardization reduces the production costs as well as inventory costs for the factory and repair shops.

This means the money for purchasing and servicing your Mercedes-Benz goes more to aspects that add value and less to inefficiencies.