Is this 75 300D worth it? My Litany of Woes - Photos - PeachParts Mercedes-Benz Forum

1975300D · #1 08-23-2011, 04:09 PM

As you may know by now I have a 75 300 inherited from my father. The problem is that I don't think I will have the money, nor the knowledge in lieu of money, to get it roadworthy.

It's a shame, because the car has virtually no corrosion, the body is perfect, the interior upholstery is great, it has a new tranny, and the engine only has 136K. And until today, she was even starting and idling perfectly.

But here are the list of problems I have uncovered which I have been unable to address:

1. Blower motor non functioning. (I understand that is a big ticket item. Requires removal of dash, which means removal of things on dash which I have no idea how that is done since they have no screws securing them.)

2. Fuel sender not working. (it has been cleaned but the gauge does not respond - dealer wants hundreds of dollars and i don't even know if it is the sender's fault)

3. Front marker lamps not working. (new bulbs but no joy)

4. Instrument panel lights non functioning. (removal of dash again?)

5. Instrument panel brake light non functioning (see above)

6. Sticky ignition lock (see above)

7. And now, the starter motor won't respond to the key

8. Not to mention, but i will, that the foam under the perfect upholstery has disintegrated and needs to be replaced (I imagine that to be at least $2000.)

I'm wondering if taking the car to someone who is good at auto electrics would be an option. Problem is the car is worth about $5000 in road worthy condition, but it might take that much just to get it there.

Suggestions? Should i just cut my losses now and sell it as is? But even so, I need to get it started to show the motor and tranny work.

Thanks

Mark

1975300D · #2 08-23-2011, 04:13 PM

More photos of the car in question

kerry · #3 08-23-2011, 04:18 PM

Almost all of those problems are caused by your malfunctioning ignition switch. once that is fixed, most of those problems will disappear. (that's my educated hypothesis at least)

1975300D · #4 08-23-2011, 04:31 PM

Kerry, how do you figure? Most of the accessories in the car work. For example, the low fuel light comes on when I turn the key to accessory. So power is getting to the sender.
The instrument lights should work when the light switch is turned on, as the rear side marker lights and front standing lights work. So we know the key is sending power to accessories, right?

kerry · #5 08-23-2011, 04:58 PM

But we also know the ignition is ****ed up somehow since it's not sending power to the starter. I wouldn't mess with anything else electrical until that issue was resolved since the ignition is involved with those other circuits in some way.

tomscat1 · #6 08-23-2011, 05:28 PM

Quote:

Originally Posted by kerry

But we also know the ignition is ****ed up somehow since it's not sending power to the starter. I wouldn't mess with anything else electrical until that issue was resolved since the ignition is involved with those other circuits in some way.

What he said. Most of those problems are mickey mouse issues, probably bad connections or grounds. Ignition is the biggest, and I'd get that taken care of quickly. The blower issue may not be the blower itself, but a resistor in the dash. Someone here had a thread on it a while back. I took mine all apart to find the motor was fine. PITA.
the starter issue is probably an ignition issue. None of those things justify IMHO getting rid of the car, which seems to be a beauty. Take time and patience, and you will solve them all. It ain't rocket science.

1975300D · #7 08-23-2011, 06:24 PM

So it looks like I have to remove the dash, eh, just to check the resister? How does one remove the vent handles, and the climate control knobs and that stuff?

ashedd · #8 08-23-2011, 06:44 PM

Quote:

Originally Posted by kerry

But we also know the ignition is ****ed up somehow since it's not sending power to the starter. I wouldn't mess with anything else electrical until that issue was resolved since the ignition is involved with those other circuits in some way.

How the heck did you fool the automated censors lol

Sometimes there is no better way to make a point.

kerry · #9 08-23-2011, 06:46 PM

I was wondering the same thing. Next thing you know I'll be accused of paying off the moderators

1975300D · #10 08-23-2011, 06:52 PM

I guess the filter didn't take into account past tense.

See how I can figure out anomalies that have nothing to do with my 75 300D?

79Mercy · #11 08-23-2011, 07:15 PM

1. Which blower motor? AC or heater?
2. pull sendor back out and make sure all 3 wires are okay
3. bad grounds or dirty contacts
4.bad rheostat, by-pass with a piece of wire. Pull gauge cluster
5. burned out bulb?
6. could be a bad ignition assembly
7. see my post in other thread
8. you could pull seat covers and replace padding yourself.

Yak · #12 08-23-2011, 07:38 PM

I'll ask something stupid: have you checked the fuses?

And I mean really checked the fuses, as in "pull them out, clean them up, look really closely for a hairline crack, clean up the fuse box, and then put them back in" checked the fuses?

Some of the other stuff may be related, or it may be accumulation of age and some coincidence.

Find a wiring diagram. If I had one for that vintage, I'd look things up. Since I don't, I'll postulate that you've got some common problem for the cluster.

You say the low light comes on but the gauge doesn't work. Are you sure you're not just out of fuel? There's no "light self test" in these older cars, so either the light works and is saying you're out of fuel, so the level is low and maybe doesn't register, or the light illuminates but is working incorrectly so there's a problem in the cluster, like maybe a cracked trace or some reverse path to ground. Fixing a cluster trace might be easy. There's a sticky.

Are you sure your rheostat for the cluster is okay? That's a common failure. Or maybe it's adjusted all the way down so the bulbs look like they're not working?

But because you've got a few related issues on the cluster (2, 4 5 on your list) I'd guess something loose/cracked their and not operator error.

For #3 - have you checked every switch setting for the lights? They should be independent of the ignition switch and illuminate in OFF or RUN. What about the turn signals? Have you checked the "standlicht" feature by rotating the switch to the left to see if that turns the bulb on (depending on position).

It's possible you've got maybe three or four minor problems: a cracked trace in the cluster, maybe a bad light switch (try the stalk, too), probably a bad or failing ignition switch. Maybe you're out of fuel.

It's too early to throw in the towel. That's not really even a litany of woes, just a list of minor problems.

barry123400 · #13 08-23-2011, 07:42 PM

Great chance to learn how to work around cars. Paid for garage service is usually to be avoided with older vehicles. Usually requires mucho dollars.

The strong point of these cars generally speaking is you can learn to repair them yourself. Otherwise some wise person years ago coined the expression money pit.

With intelligent use of this site you have it made in the shade compared to what things where years ago.

1975300D · #14 08-23-2011, 08:01 PM

Yak, the fuses are good. They have to be, because other things on the same fuse work.

re: the fuel gauge, no I have lots of fuel. In fact, when I pulled the sender out, I can see it is about half full. The fuel sender is the one that really bugs me. I checked the connections and in fact re-soldered two of them. There is voltage coming through the wires and the sender has continuity. I cleaned it up real nice, too.

The rheostat button could the problem with the instrument lights. I can turn it infinity in both directions. I assume that is not right. (another reason I guess to take the dash off.)

For No 3, yes, I checked every setting. The front side marker lights don't come on. I assume the front yellow ones should come on when the back red ones come on, right? The back red ones work fine.

1975300D · #15 08-23-2011, 08:03 PM

79Mercy, I assume that there is only one blower motor. I am referring to the fan controlled by the dial in the middle of the climate control unit. The one that has defrost written on it. That controls fan speed.