Electrical failure - won't charge. New OVP + Alternator = nothing! ON TWO CARS!

[Sulaco]

1994 E320
1994 C280

Both cars had squeeky belts. I ordered correct replacements.

While waiting on my new belts, I spray belt dressing on both belts to hush the squeek for a few days.

Next day, on the interstate in the w124. I notice the ABS light is on. Whenever I hit a blinker or the brake pedal, I notice some odd power fluctuations. The radio would restart itself. The AC fan would stop and start. We get into traffic, and it starts hesitating at low RPM's and dies. Won't start, battery is dead. Won't even click. I get suspicious it's the OVP. I order a new OVP.

Next day, I take my C280. It appears fine. When I leave work, I notice the battery was a little dim when cranking it. But, it starts fine.

Half way home. ABS light. I turn off the AC and light goes away. Light comes back on later. I turn off the radio and light goes away. Eventually it comes back on again and only goes off when I release throttle (I'm doing 80mph). I get ALMOST home and it dies. Won't start. Battery is dead.

I think WOW TWO OVP'S IN TWO DAYS. Doubtful.

My wife brings me the new OVP and jumper cables. No dice. The car won't even run with the jumper cables connected. New OVP or old, same result. Won't start. Can crank and crank and almost start, but won't start. Tow it home.

I put the new OVP on the E320, no dice. I hook it up to jumper cables. It will start and run with the jumper cables attached. But after I disconnect them, it will do the same things again and die.

I'm absolutely befuddled. My mind is blown.

Now, all I can think of is it has to be related to the belt dressing. That's the only thing I did on both cars (the day before). I pop the hood and take notice to where I was spraying it. On both cars, I was spraying it on the passenger side near the alternator. Father in law suggests belt dressing could be in the alternator grounding it or lubricating the brushes and preventing it from charging. However, the C280 won't even run with the jumper cables attached, but the E320 will.

I remove both alternators and take them to get tested. Both fail. I buy the only new alternator in town (it fits both cars). The OVP fits both cars too. I put both of those on the w202, but it still won't start. It will turn and turn, but no start. I put both those new parts on the w124, and it will start when jumped but will die in a minute after I remove jumper cables, just like before.

ARGH

I'm completely and totally lost. I'm desperate for ideas! Help!

[BillKerler]

Brian, I will give it some thought.
Question #1, why was the belt squeaking?
On my W202 ('94C280), the only time I have ever had a squeaking belt was because the radiator hose that is mostly hidden by the front engine head black plastic cover had a small rip in it from age spewing out a fine spray of radiator fluid coating my serpentine belt to the point it was slippery and squeaking.
I think you should try and figure out why your car's belt was squeaking.
Is the belt dry? Is it cracked and aging? Didn't you replace your tensioner about a year ago (and the belt too)?
Take apart the old alternator...why do you think it broke?
Since the alternator broke, did it do damage to the voltage regulator?
With a digital voltmeter, what voltage is in your system when cranking/running the engine?
I will keep giving it some thought.
I have used belt dressing in the past on a number of cars with the alternator/generator right there and never have I had this kind of trouble.
Yet the car dying surely has something to do with the dressing (both cars).
I feel for you.
Bill

[Sulaco]

Bill! I'm so glad you responded.

I replaced the tensioner about a year ago, or more. I had that drastic problem with the broken bolt to deal with. It was a nightmare.

I did not replace the belt at the time, as it appeared to have some life left in it. About 6 months later it intermittently started to squeek at cold temps. I also found a coolant leak that was really weird and intermittent. The squeeking would get worse after it leaked (which it only leaked at high temps around the thermostat housing). I'd tighten the belt and the squeek would go away until the next leak. Eventually, the belt appeared to stretch so far that I couldn't get it tight enough to get rid of the squeek. So, I ordered the hose to fix the leak and ordered a new belt. (At this exact same time, the E320 just had a really old belt and was squeeling at cold temps or with AC on, I ordered a belt for it while I was at it). In the mean time, I bought a can of belt dressing to patch the squeel until my new belts arrived... And here we are.

From this point forward, I will leave the E320 out of it and focus on the C280, for simplicity's sake.

With new OVP or old OVP, won't start. It will crank and will VERY BRIEFLY try to start, but will fail and just keep cranking. With new alternator or old alternator, same thing. Had both batteries tested for hours at autozone = both good and now fully charged.

I've noticed one more thing that's very out of the ordinary. When I turn the key to the ON position to look at all the lights on the dash, I can hear an abnormal WHIRRING noise under the hood. It's coming from the ABS pump. It's never done that before. So apparently there's something sending power to the ABS pump when it's not supposed to be.

[BillKerler]

When the c280 starts to crank, do you have spark...can you take a spark plug boot off, hold it close to a ground source and try to get a spark from the metal female portion of the boot to a ground source while somebody is cranking the engine.
If you have spark, then something is up with air/fuel ratio.
Can you borrow the diagnostic code readout from Autozone to hook up to underneath dash in driver's footwell to read codes from the computers?
Is your check engine light lit?

[Sulaco]

CEL has been lit for months due to a clogged EGR that I've been ignoring. I have no idea why I didn't think to check to see if it was pulling any more codes!

I pulled the battery to get tested at autozone (it passed), but it wiped the memory! Damn.

[BillKerler]

German cars do not lose their memory when battery voltage is removed. Many cars do lose their memory, but not Audi, BMW, Mercedes, etc. Yoiu should still be able to pull codes. There are 2 EGR valves on the C280...which one is stuck? The one closest to the firewall, or the one mid engine? My mid engine EGR stuck, I removed it, squirted in WD-40, put a little bit of heat on it via a propane torch, and it popped open when I put a vacuum on it (I used a brake bleeding tool to pull 15" of vacuum). It's worked like a champ ever since. The EGR towards the firewall had a huge air leak through the packing material around the shaft that goes up and down whether there is vacuum or not. That one I had to replace and I got a good price from Autohas in Arizona. About 1/4th of all the combustion air I needed for idle was leaking through that EGR due to the packing material gone because of engine heat. What a huge difference in car performance once that EGR was fixed.

[BillKerler]

You know, I read something today about the cam shaft sensor screwing up the signal to the primary side of the ignition coils...a car starts up, and then dies immediately. Both the crankshaft sensor and the cam shaft sensor play a role in ignition on the c280. I think your car has been running marginally because of old oxygen sensors, stuck/leaking egr valve(s) and probably some vacuum leaks...the car is 17 years old. But something put it over the edge after you sprayed the belt dressing...the cam shaft sensor is up front on the engine head on the driver's side kind of across from the water pump/thermostat housing...did the dressing get into the plug connector to short out the wiring like it shorted out your alternator? Just how liberal were you when you sprayed on the dressing...dripping wet? The cam shaft sensor is a magnetic plug on the camshaft pulley and the wiring on the cylinder head goes to a coil which picks up the magnetic plug everytime it rotates by (the infamous Hall effect). Mess this up, and the car won't run. The dressing had to do damage to something up front of the engine.

[Sulaco]

That's a very interesting turn. I didn't think about that. I replaced the O2 sensors last year but other than the MAF, I've never replaced any of the other sensors on the car. It's also had an intermittent hard-start problem for like a decade that I've just ignored.

I wasn't too liberal on the dressing. I applied it with the car running. I leaned in where the belt passes around the alternator pulley and just held the button down long enough for the belt to make a complete lap on the inside and outside, to make sure I had gotten every inch of it. The squeek was almost gone, but now it wasn't constant. It was like a tiny part of the belt was still slipping. instead of a constant SCREEEEEEEEEEEEEECH when I was accelerating, it would SQUEAK SQUEAK SQUEAK SQUEAK SQUEAK SQUEAK the entire way. Maybe the constant gripping/slipping on the alternator didn't help?

Excellent advice on the EGR. My EGR is all factory original and untouched, and it's been throwing a CEL for the EGR for like 3 years and I've just ignored it, as it isn't crucial for the function of the car. Perhaps the EGR is to blame for my huge lack in horsepower and gas mileage.

I removed the alternator from the car and put it on the E320. The E320 was still cranking and running, but only sending 12.6v to the battery. I took it to the local shop and they replaced my new chinese made OVP with an OES version and it fixed it right up. It's now sending 14.2 to the battery.

Anyway, with the alternator removed from the C280 but the battery fully charged and still connected, the ABS pump would still go haywire whenever I turned the key on. After sitting for 2 days, the battery is almost completely dead, so it's shorting somewhere. still. The E320 was easiest to fix judging by its symptoms. The wife is 34 weeks pregnant, so getting her car going took more priority over my own. Now, I need my beloved C280 going for when the baby gets here. Daddy's gonna need his first child working again! Though, I've been keeping my eye on a few local w123 240d's and 300d's as a backup in case the C280 is a lost cause...

[BillKerler]

Yes you have an electrical short. You have replaced your wiring harness, right? It seems the short really popped up after the belt dressing application. So the offending wires should be up front of the engine. The wiring harness goes right in front of the engine head for wires leading to the solenoid controlling the 2 egr valves, plus wiring to the electrical air pump, the alternator and I don't know what else.
If a visual inspection doesn't reveal the possible shorting area, then all I know to do is hook up a digital meter red wire to the + wire going to the battery and the black digital meter wire to the battery post for + and measure dc amperage. When I had this problem with a BMW years ago, I had a reading of about 300 to 400 milliamps and it took a couple of days to drain the battery...it was a silly wire arcing against the hood when the hood was closed. But I had to disconnect any suspect wires one at a time and then look at my dc amperage reading...when the reading goes to less than 70 milliamps, you know you have found the offending wire. There will always be some amperage flow for your alarm security features like the radio and such.
What's with the hard starting? Was the engine hot or cold? What other things did you notice during the hard start periods? Would it start and die? Or just endlessly crank?
Congratulations on the new baby...boy or girl...or are you going to just be surprised the day of the birth?
Bill

[BillKerler]

Where are all the other guys who use to post on club 202 with really useful advice? There use to be a half dozen guys you could count on to try and help...what's happened?

[strictlyspeakin]

Try disconnecting the leads on the stop lamp switch and turning the key on. Does the ABS pump stop?
I also like Bill's idea of checking the current draw. Charge the battery and check the draw, then pull the ABS Control Module and recheck the draw left side of the engine . Car off of course.

How old is your water pump? You've got a new alternator and new idle pulley, you're running out of things that can make it squeel. You seem sure that the leak was near the thermostat. In my 94 the bearing in the water pump started to fail and the leak was small at the start.

[Sulaco]

Alright, I've gotten my parts car home and started parts swapping today.

Put in known-working alternator and OVP. Put it all back together = no dice. Still won't crank.

It almost TRIES to for a split second but just keeps turning and turning. I can smell a hint of gas coming from the tailpipe. Swapped out the fuel pump relay just to be sure. Nothing.

Where is the ABS control module?

I seriously need to track down why I'm not getting spark. Once I get the car running I'll worry about squeek, EGR, etc. But the baby (boy, by the way, named Owen) is due in 2 weeks and I'm without a fully functioning vehicle! The E320 is running but keeps trying to overheat! But that's a topic for another day...

[Sulaco]

I found the ABS control unit. Swapped it with the one from my parts car. Tried it, started right up! But then died about 2 seconds later... No dice.

Went and swapped the ECU and whatever the third computer box is with the ones from the parts car = no dice. Swapped OVP with new OEM from the E320. Cranked and ran for a second again! Then died. Old OVP into E320 which worked fine in the E320. Looks like my OVP was never dead to begin with.

After swapping the ABS modules, the ABS pump no longer runs full blast when I turn the key on.

[strictlyspeakin]

Congrats on the baby boy...almost here.
Is the car throwing any codes? Does the car still run as long as the jumper cables are attached?

[Sulaco]

Car does not run at all, that was the E320 which is fixed.

[Sulaco]

Installed new wiring harness = no dice.

[Sulaco]

Bought a new actron OBDII scanner: cannot connect to ECU. Reads "NO LINK" when I turn the key on and press READ.

[Sulaco]

I think it might have a fuel supply problem as well. I'm not quite sure yet. How could I tell?

NOTE: I've already swapped fuel pump relay.

[Sulaco]

News: I can tell the fuel pump isn't running. Further tests show the fuel pump isn't getting any power. I disconnect the power cable to the fuel pump (in the trunk). I ran some wires from the pump's power leads to the battery itself and heard it start whirring.

Tried to start the car, and it ALMOST starts. Repeatedly. It'll turn, start to fire, then turn and turn. Sometimes it will just repeatedly start to fire but will never actually start. It will sometimes get so close to starting that it will stop the starter.

The hell!!!!

Also, with a known-good fuel pump and relay, it's not getting power. I can jump the leads under the relay but it doesn't force 12v to the pump like it used to. For some reason the pump isn't getting (enough) power. And after I force power, it still doesn't start the engine!

[Sulaco]

tested fuel pressure at the fuel rail and it was noticeably low. I don't have a pressure gauge so I was just eye-balling it. I turn the key on and press in on the valve and some fuel comes out. I go over to my working 94 E320 (same engine) and perform the same test: fuel SPRAYS out with immense force like a sprinkler.

Replace fuel pump with pump from parts car. Car is a LITTLE closer to starting, but not quite there.

The car had about 1/4 tank in it when this all started, and that same 1/4 tank is in it. On a whim, I add about 10 ounces of gasoline I siphoned from the parts car.

Car starts right up.

What. The. Hell.

It starts right up but runs like COMPLETE shit. It can hold idle, but just hardly. I rev it and it sputters but the RPM's climb. Thinking it's bad gas from the parts car, I go get some fresh 93. About 6 gallons. Bring them back, put them in the tank, and it's still running like shit. I let it sit and idle about 10 minutes and it got noticeably better, but definitely still not 100%.

I check every fuse in the fuse box, and notice the fuses for the radio and secondary air pump are blown. I replace them.

I still don't have a CEL. The CEL light doesn't even come on when I turn the key. Furthermore, my OBDII scanner still says NO LINK when I try to pull codes. That MUST be related to what's going on here. I've already replaced the ECU, so it's not that. There must be something else going on preventing me from getting any codes.

Could it be that the OBDII circuit relies on having a good CEL bulb? I imagine this would prevent emissions bandits from simply unplugging their CEL light to get their registration renewed. Just a hunch though...

[strictlyspeakin]

For my 94 C220 the car must be ON for the OBD to work. Are you trying while the car is running?

I've heard of people taking the CEL bulb out and trying to make it thru inspection. They failed because the bulb was out. Not sure how the inspectors knew. Maybe they are trained to look when starting the car. Anyway, for most of the wiring diagrams I've looked at, the bulb is at an end point in the circuit. A lead comes into a pin in the dash telling the bulb to light.

Can you drain the tank to start with good fuel? Changing the fuel filter might be good too. You're still stuck facing the reason for no power. I'll think on that one.

[Sulaco]

I've tried every combination. It used to work just fine, prior to this meltdown.

I actually have this bluetooth OBDII scanner. It would connect with my android smartphone using a $5 app called "Torque."

It was brilliant. It would monitor every function and sensor on the car. It would even measure 0-60 and 1/4 times, everything. MPG, air temps at several locations, etc.

You could even set it up to automatically email you summaries, logs, and alerts using parameters you configured. After each trip, if you wanted, it'd email you the stats on your car's performance as well as the trip itself.

This is the number one reason I miss my android smartphone. I currently have a windows phone, and am eagerly awaiting the Torque app to show up in the marketplace.

If you've already got an android phone, it's roughly $20 for the bluetooth OBDII reader and $5 for the app. A truly outstanding deal!

Anyway. I figured out a trick to pull codes. It's very inconvenient, but it works. I simply put my car's ECU into the parts car. Hooked up a jump kit to get power, and turned the car on to pull codes. It's a hassle, but it worked. My actron scanner told me "0 codes" but also told me some other faults that simply said:

Catalyst
Evap
Sec Air
02 Sensor
02 Heater
EGR
Misfire
Fuel
Comp

Curious, since I'd replaced both O2 sensors last summer and cleared the codes. I know my EGR system is completely dead, which I think could explain the AWFUL performance of the engine the last 6 months or so.