20 Most Recent 1984 Mercedes-Benz Mercedes Benz 300 Class Questions & Answers

Barrel fuses used to be made of aluminum and corrode on the copper contacts. Pull fuses and replace. 10-15 dollars now will help get rid of electrical gremlins.

what procedure did you use to test the motor? if you fed power to it and it moves down swap the wires around and it should go up. Being a dc motor if you feed a + positive and - negative to it it should move one way to go down then swap the wires opposite and it should go up, if it does not than the motor is bad. If you need further help, I’m available over the phone at https://www.6ya.com/expert/david_4c166ba81493f541

If you mean Remote trunk release, there isn't one. It's controlled by vacuum. If system works good, when you unlock the doors with the key or the inside door switch, it will unlock the trunk (if the button is in the unlock position). And vice versa.

install the bottom half into the pan as far as it goes, the install the top half to it and the 2 bolts to bottom of the turbo. the slide the rubber grommet on the bottom section down into the oil pan until it is seated, next using a slip jaw pliers grab the bottom section and slide it straight up into the top pipe section which also the seals it into the bottom rubber grommet, I hope this helps.

If you are certain that the fuse is okay, next replace the Multi-Purpose Relay/Combination Relay. This relay controls all three of those devices and is most likely your culprit. I would try the junkyard first and grab two just to be on the safeside. You'll find it under the fuse box cover on the driver's side engine bay.

ignition switches are a known issue with this era mercedes. Not too difficult to change the ignition switch. Google is good source for pics, videos and instructions on this. Be aware that the switch is about $400 from the dealer. You could get one without matching key for alot cheaper if you dont care about that. Also, you can get one without the key lock for much cheaper if you are able to remove the key lock from your existing switch.

for one thing, you have a vacuum leak. this is causing the locks and engine shut down issue. start by disconnecting the vacuum tube that goes from the engine compartment through the firewall to the inside of the car (drivers side near brake booster/reservoir). disconnect and cap the engine side and tape to make an airtight seal. now, if the engine shuts down with the key, the leak is inside the car somewhere. to isolate inside the car, disconnect vacuum at each door 1 at a time and see if the other locks work. If you get this far, remember, you have to hook up the vacuum tube you capped in the engine compartment.

that sounds like the fuel return hose on one of your fuel injectors. You should get about 2 ft of hose and replace all of them including the one in back that is capped and the one to the injector pump. Im guessing when this happens there is fuel everywhere?

You have a vacuum leak. If you open the hood and look on top of the engine, there is a lever one the right side (looking at the front of the car) with a red "Stop" decal on it. Push the lever and the engine will stop. Look for any small plastic vacuum tubing that may have come disconnected. If you dont find any, it may be a line inside the car. For temporary relief, you can pull the rubber junction from the vacuum tube that goes through the firewall to the inside of the car and cap it. If the engine now shuts off with the key, that does mean your leak is inside the car (4 door locks and trunk release are all vacuum operated and have tubes going to them).

Use two hooked anythings and put in each side of cluster and pull straight out. It's only held in by four pieces of friction rubber. Two on top and two on bottom. When loose mark and remove bulbs, speedo cable.

Bad Ignition Switch

check primary fuel filter for diesel.If none take hose and blow back to tank.You should hear air bubbling. then try letting pump pick up fuel.You could have a clogged screen in the tank.

I am sorry but we have no such diagram. You kau be able to find iut here www.alldatadiy.com

First
Make sure your dash "dimmer" is not turned all the way done, its a small rod thats twists clockwise to increase dash illumination, counter clockwise to decrease...
Next..the bulbs in the back of the gauge cluster might be burned out , if they are the original bulbs, thats probably the case...

The pump is self bleeding so that is not the problem. I do suggest you hold the throttle to just short of full opening during cranking to gain max flow through injectors.

Well, that's pretty dangerous! I wouldn't want to ride with you at night. I'd look over and see your way of not blinding on-coming drivers, one hand on the wheel and one holding some lever to keep your lights on dim, and I'd start freaking, man, and probably blathering something like, ya know if you tried a NEW DIMMER SWITCH for this old car, I bet it would fix that problem. Can I get off here? Thank you. I can imagine there is a wide source of places you could find new parts for the mercedes, all kinds of multi-function or dimmer switches, and everything else to go another 30 years, lol.

try autozone.com to see if they have your car listed for diagrams pictures and step by step instructions if your car is not listed then try your local library they have all the car manuals and even copy them for you