Sorry but I doubt that would work. Look over it real good with good light. Try to find ANY markings on it you can and report back. You might be able wash it off too.

Do you own a multimeter? There may be a way to come up with a ball park value. Take some high res pics and post them so I can see them.

Someone in a store is going to look at it and say your SOL. Or "whats that?"

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08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

I'm thinking resistor too. Other forum members are correct about measurement of resistance. This is something you don't want to guess at or you'll fry something even more expensive.

I've got an old temp/oil/fuel guage in storage. I'll see if I can find something out about the resistance value OR the idea about reading the schematics will do just as well.

You can then replace the resistor with one of equal or higher tolerance and heat dissipation ability.

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

The fuel gauge next to it has the same resistor and the numbers on it are:

68R 10%

I'm hoping that is the same value for the temperature gauge.

I went to MB to see if they could tell me what the value of the temperature resistor is. They parts guy looked around for a bit until the older parts guy told him they don't have that information. Which doesn't surprise me.

But the parts manager gave me the number of a guy who specializes in fixing instrument clusters. Perfect, I thought. He would know. So I called the man and told him MB had given me his number and that I was wondering if he would know what the value of the resistor would be.

He told me that I could bring it in and they would fix it, but that he wouldn't tell me the resistor value. Say what?

"I won't tell you," he said.



So I said thanks, and muttered ********* under my breath as I hung up.

Well, he must have have heard that. One minute later, the my phone rings.

Me: Hello

Him: Why you call me *********?!!



Incidentally, MB told me a replacement temperature cluster was $450. The only way they can justify charging those incredible prices for parts for cars that supposedly aren't worth anything, is supply and demand. Market forces. There must be enough people who own these cars who are, in fact, willing to pay those prices. Which would indicate to me that people with money, however you want to define that, buy these cars, and love these cars enough to put that kind of money into them. So why don't they sell for more?

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1975 300D

68R means nothing. 10% is the tolerance. So if a resistor is 100 ohm at 10%, it can be anywhere between 95 and 105 ohms. But, that doesnt really matter right now.

I would doubt it's the same value as the temp gauge. Two different types of circuits.

"I won't tell you".. he has obviously reverse engineered all the gauges he works on and wants to be the only guy in town fixing them. I bet he even makes the new part values unreadable.

Now that you pissed him off you can no hope of getting that info lol. I would have offered him money to tell me the values OR paid for a replacement resistor from him. Like I said, he likely destroys the markings.

So two choices here: Buy a replacement form the classic center, measure the values THEN return it for a refund.

Find someone with old gauges that will measure them.

Another is finding schematics. But MB will say it's proprietary and refuse. If we knew someone who has engineered these types of automotive circuits then he may be able to figure it out.

And last but not least..
Tell me if you have a multi meter and do you know how to measure resistance with it? If that is a carbon resistor(remember I asked for high res pics) we might be able to measure something off of it.

__________________
08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

Take the resistor from the other gauge and put it in your burned gauge. If it works, measure it and buy one of that resistance and wattage.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Then call the guy you called "*******" and tell him the resistor value.

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2010 ML350 Bluetec
2012 Mustang Convertible

I called up several electronic supply stores, and would you believe it, they don't sell electronic supplies! lol. At least they don't sell resistors. Maybe just capacitors and diodes.

But Radio Shack said they do sell resistors but their tolerance is 5%. And they have some that are 68. So I'm wondering if that would work.

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1975 300D

I do have a multimeter, but not sure how do measure resistance. I know it has that horseshoe symbol, right?

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1975 300D

68R means nothing

I did some googling and I found out that R refers to no multiplier. So a 68R would be 68 ohms.

So radio shack has a 68 ohm resister but with a 5% tolerance. So it might not work, but it would be safe to try. The worst that can happen is it it will blow.

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1975 300D

Actually 5 % tolerance is better than 10% tolerance. mainly worry about resistance value and power handling or heat dissipating capacity ro wattage.

__________________
2010 ML350 Bluetec
2012 Mustang Convertible

So with resistors, I would want to make sure that I don't use one with a lower resistance rating, right? That means more juice will get through.

If less current gets through than is normal, then my temp gauge will under read the temperature, right?

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1975 300D

if you want to put a 68 ohm resistor in there fine, that very well might be the right value. But you need a 5 watt or higher resistor. The ones that radio shack(a cell phone store) still have laying around after all these years, are likely 1/4 watt, 1/2 watt.

You will likely have to order it online. Put it in, start the car, then keep checking the gauge to see if it work right. You will also have to keep touching the resistor to see if it's getting hot. If it gets too hot it will blow in half. If it get really warm it may hold together but will likely be melting wires on your harness somewhere. It could possibly work fine for awhile and then one day you will have an electrical fire while sitting at a stop light.

With resistors you need to replace with actual value or very very close. They limit current. Capacitors have much more wiggle room, some value or larger and you are usually good to go.

Do NOT take any advice from ANYONE working at radio shack.

A 5 watt will be ceramic.

__________________
08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

Assuming that is how the resistor works in the circuit.. sure.

__________________
08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

Ashedd, is a 5W resistor safe?

The 68 ohms I read was off the fuel gauge resistor. It looks the same, but I don't think it is because it has no Watt rating on it, but the burnt one from the temp gauge has a "W" I can make out at the end.

__________________
1975 300D

I say ya because it "looks" like an old 5 watt resistor. You really need to find someone with another gauge so we can figure this out.

__________________
08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D