Let's do some diagnostics.

1. Charge your battery and start the car. (Full charge = 12.6)
2. Connect volt meter acros battery terminals. Running should = approx 14 V IF the glow plugs aren't pulling voltage. Low charge could be voltage regulator, bad diodes or other internal alternator problem. (Google for more info than you want)
3. Turn off car. Turn off all electrical items. Disconnect neg battery cable from post. Connect ammeter between terminal and post. Should have < 50 ma of current flowing.

Problem is either alternator, battery or wiring. Inexpensive meter will diagnose. The chain stores also have diagnostic tools that htey can hook up but you need to confirm their diagnosis. I've had them say my alternator was bad when the glow plugs or grid heater (on the diesel ram) were simply working as designed. Keep your old battery for a swap when convenient if it is in fact the problem. A $10 trickle charger from harbor freight will greatly extend battery life on batteries that aren't driven frequently.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Simple solution to getting your car to start.
1/ put battery on a charger over night.
2/ try & start car. if battery is dead after over night charge > dead battery
3/ once started and run for at least 10 minutes, not 2 or 5, with out lights or fan or any other electrical stuff on. check voltage at battery with car at aprox 1500rpm, should be at least 13 v, if not then charge problem.
4/ Once car has been run and all appears ok. try and disconnect battery and leave for a few days, if battery goes flat then battery is a problem. Could take battery and have tested.
4/ What would happen if your mustang was left out of the garage in the weather, would it still start after a week?

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

I agree with the current drain idea. The testing by trying to see if there is a big spark or with sufficient capacity amp-meter is advisable. (Never try to spark a battery with the filler caps off.)

First thing I'd do is remove the battery and do the suggested trickle charge overnight. Will get the battery charged and warm it up at the same time. Make sure terminals are clean.

Second, I'd have another car there with the jumper cables hooked up while I pre-glow the heck out of the car. Glow plugs on your car may be weak.

Third, never use starting fluid on a diesel. Some say a little WD-40 in the intake may help.

What viscosity is the oil? Is it Multivis?

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Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)

Thank you, all, for the advice. Please read to the bottom. I may have more of an issue on my hands than originally thought.

I jumped the car last night using the Mustang battery. It took a while and some high revs on the V8, but the Merc started up. It was 25F outside so I was happy.

I drove the car around for 20 minutes. Turned it off, turned it back on. All good.

Voltmeter Diagnostics:

With the car running: 13.5V

Car running with headlights on: 13.3V

Car running with headlights/heater/domelight on: 12.9 ~ 13.2V (approx.)

Car off: 12.8V

I think the battery is good.


This morning (around 30F), I tried to start the car. All the dash lights came on, the glow-plugs cycled a few times (I could hear the relay clicking off), everything seemed fine. Then I hit the switch... NOTHING. Not even the slow cranking I was getting yesterday. The starter didn't come on at all.

I checked to make sure the car was in Park. OK. Tried again. Nothing.

I tried a third time. I tried pre-glowing and then the car started making a very loud buzzing noise. Opened up the hood and it's coming from my glow-plug relay box. Checked the fuse, it looks OK. Loud buzzing. It sounds unhealthy.

What the hell is going on??? (Sidenote: I disconnected the power cable going to my after-market radio because not only is it crap, but the clock may have been what was draining the battery. Not sure if this may have caused an issue or not).

Glow-plugs cycle OK.

Hit the ignition = NOTHING.

Try again = Loud Buzzing, no pre-glow (probably because the battery lost its juice again).

What did I just break?

Thanks, all

PS layback40 - The Mustang was sitting around in the garage much longer than the Merc. The garage isn't insulated. It's probably the same temperature inside as outside. And it started right up AND started up the Merc. It's a newer car so it's not surprising. My only point was that the battery itself shouldn't be dying just because it's cold out. Does that make sense? Thanks for the help, I really appreciate it.

__________________
Alex
1984 300CD - Silver/Blue - 326,000 miles (sold)
1979 240D - Canary/Brown - 221,222 miles (I love this car)

The oil in there is Rotella 15W-40.

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Alex
1984 300CD - Silver/Blue - 326,000 miles (sold)
1979 240D - Canary/Brown - 221,222 miles (I love this car)

A few years ago I was looking for a battery for my p/u . . . sears website wanted to know where I lived, so they could give me a "cold weather" or a "hot weather" battery! Apparently they make batteries different for different conditions, like in Fl it is very infrequent to have much below 30 degrees, but high heat is more likely, and batteries don't like that either, could be you got a "Southern Battery" . . .

Sounds like you have a glow plug relay issue also . . . Diesel Giant's website has a good tutorial . . .

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82 240D Manual 277K and still rolling!
02 Volvo S60 AWD For Sale

Deal with the "No Crank" first. It likely means that current isn't getting through the solenoid. The question is "Why?" Either your battery is down & not supplying enough juice (measure volts across battery terminal to check charge (full = 12.7)) or the trigger wire isn't getting current to close the solenoid with the key at "start". Also note if measured voltage drops when you hit start. That would be equivalent to a load test. You might also charge the battery & take it to a store for testing.

Have you googled for more understanding? ie parasitic drain, engine no crank You have a very standard starting system and detailed information is available. Drains may be difficult to find but shouldn't be difficult to diagnose. What happened with the spark test or ammeter measurement?

You didn't break anything. It is already broken.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

All these readings point to the charging system being functional. It seems the battery is good but doesn't necessarily confirm it. It could still drain down on its own after sitting.


It seems you have a faulty GP relay. I had the same thing and it took out at least two alternators and one battery. It seemed the only clue was a hissing (just as you described) coming from the relay and occasionally my GP light would come on while driving. It would test good usually with a voltmeter but since I replaced it this summer I haven't had ANY charging issues like I used to. You can get a new afterglow relay and 4 GPs from Fastlane for a decent price-
http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1984@@1984&makeid=63@@MERCEDES+BENZ@@X&modelid=6208%3AMBC%7C1510%3AED%7C10000134@@300SD&keyword=relay@@relay&catid=All@@All&subcatid=P%3A242005@@Preglow+Time+Relay&applicationid=W0133-1606169&mode=PA




Keep the clock and the radio disconnected and see if that helps the drain. You could have both the Glow Relay being bad AND the clock/radio causing excessive drain or just one or the other.


Follow Junkman's advice and look into the no crank issue first. Check the voltage on the battery BEFORE you try and start it. Then try and start is and check the voltage after.

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

5W40 really helps starting in cold weather. You should consider switching to the Blue Rotella Jug for at least the winter months. I run it all year long.

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

Because American Mercedes don't like to be referred to as a "Merc". Merc is a Ford product and thats the rub. You can get by with calling it a Merc in England and quite possibly France, because in France everything goes, because so many are called by that low level name over there. Here in the US we all know that they respond best to the name of Mercedes Benz or even Benz or any favorite name you would like to hang on it like Heidi or Rolf,oor Donner or Blitzen, but not Merc. It just don't go! It just won't go! It just won't take a charge.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

Thanks, guys, I appreciate all the help.

I'll first try figuring out why it's not cranking. I'll take the battery out and take it to AdvancedAuto and see what they say. I'll pick up a trickle charger tonight and give it a full charge inside the house before I do. I'll try cranking after the battery's good and see what happens. Shawn, I'll also ask about the cold/hot battery. You bring up an interesting point. I may have put in a GA-weather-approved battery.

I couldn't do the spark test or the ammeter measurement last night because I was getting frostbite. I'll try again this weekend with more pairs of socks on. what does the ammeter measurement tell me?

I have to read up more about this stuff. But I guess going through this is the best way to learn it.

I'll check on the relay after I can get the car to start. I agree that I may need a new one.

Lastly, I will not call my car a Merc again and I will put in 5W-40 next time around. Thanks, again, all.

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Alex
1984 300CD - Silver/Blue - 326,000 miles (sold)
1979 240D - Canary/Brown - 221,222 miles (I love this car)

You are learning the best way possible...jumping into it head first and asking for help from people that were once in your shoes...we all had to learn some time.

__________________
2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

Charge the battery, and try taking one of the battery cables terminals off the terminal before letting it sit over night. Put it back on in the morning. If that solves your problem, then it's probably a current leak- somewhere a wire or device is shorting to ground and running the battery down. If that's the case, get the $2.99 harborfreight multimeter . Test for current through each fuse with the car off - pull the fuse, turn the multimeter to current / AMPs and put the probes on the fuse contacts, note your result, go to the next one. Somewhere you'll probably find a circuit drawing an amp or 2. In the short term, you could leave the fuse out if it's not an essential circuit, until you find the leak in the device or wire harness.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

x2 on this advice. It's a simple test. You probably did not get your battery fully charged when you got it started and it drained down again overnight. If your battery is as dead as it seems, an overnight trickle charge will probably not completely recharge it. You'll need more amperage going in to it.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

A big battery that flat will probably want about about 7-10 Amps when you start charging it, and will take about 4-8 hours to be fully charged. If you don't have a charger that will supply several Amps, drop the battery off at an autozone, pep boys, whatever, pick it up after work or the next morning. They will usually charge overnite / all day at no charge.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?