Normal? or a problem
 

After looking for nearly 2 years (and reading almost all of the archives in this forum :)), we recently added a 1987 190D 2.5 to our "stable" of diesel vehicles. It has about 165,000 miles and we are very happy with the performance and mileage. It was purchased mainly to relieve the cost of fuel that our truck was using. There are a couple of things that I'm not sure about--if they are "normal" for a Mercedes Diesel or not:

1. The radio (original Becker) makes a whistling sound that seems to follow along with the transmission either accellerating (whistle gets louder) or decellerating (quieter)

2. The radio does not seem to receive AM stations--we do live in the "country"/mountains, but most of the AM stations do come in well in the VW & Truck--is there anything we can do to "boost" other than a new radio?

3. The rear window defroster takes a LONG time to defrost (~~30-40 mins). It seems if I wait until the car is "warm" (~80c) then it works better

4. when I engaged the vacuum lock via the driver door, the alarm went off when I unlocked & opened the door. As long as I lock using the trunk it seems ok...My key is pretty worn, so I'm wondering if I should order a new key? would that help?

On the bright side, the heater warms up WAY faster than the VW which is nice on those cold mornings.

Other than the above, it starts right up in the am, even when it's freezing and runs very well. We've put almost 3000 miles in the last 2 months and get a steady 32-34 mpg.

Thanks to anyone who can help with the above issues.

Cathy & Nick

I have purchased both of the 300's with the Becker installed. In both cases the radios were quite poor with regard to AM reception, and not all that great with FM reception for that matter.

The best thing I ever did for the SDL was to purchase one of the mid-line Alpine units for about $180. from Crutchfield. The Alpine had proven itself superior to the Sony that I have in the SD. I would definitely recommend the change. You won't regret it.

My Becker (recently replaced) worked flawlessly on AM and FM alike. Defintely a 80's reciever but it worked quite alright for what it is. I did have tape deck issues but I replaced it with a CD player here recenetly. Doesn't look as nice but at 2 hours a day commute it is acceptable :-D

Answers:
 

Hello Cathy & Nick

1. The radio (original Becker) makes a whistling sound that seems to follow along with the transmission either accelerating (whistle gets louder) or decelerating (quieter)
Answer: The brushes in your alternator are bad, or the regulator is going bad, what you hear is the electrical noise of an alternator failure in process.

2. The radio does not seem to receive AM stations--we do live in the "country"/mountains, but most of the AM stations do come in well in the VW & Truck--is there anything we can do to "boost" other than a new radio?
Answer: Check the antenna cable connection on the back of radio, be sure it is fully seated, remove the mast, clean and lubricate it, reinstall and test.

3. The rear window defroster takes a LONG time to defrost (30-40 minutes). It seems if I wait until the car is "warm" (80c) then it works better
Answer: Sounds like a low or no power issue, replace all fuses with NEW ones and check for power at the glass, post the results for further help.

4. When I engaged the vacuum lock via the driver door, the alarm went off when I unlocked & opened the door. As long as I lock using the trunk it seems ok...My key is pretty worn, so I'm wondering if I should order a new key, would that help?
Answer: Get a new key and hope the lock is ok, the locks are not cheap.

My original radio/tape deck works excellently, but I am curious, should I choose to swap it out (like if I want a dash CD player or something), can the original speakers be connected to a new radio? or do I have to put in a new speaker system in order to use a new radio, if thats so, I'll be leaving it how it is. :D

Well
 

Radios don't care which speakers they connect to, but when I switch from OEM to aftermarket, I cut the wires at the speakers and run fresh wire to the new radio.
Most cars are 10+ years old when the radio needs changing, about half of the time, the OEM speakers are blown out, when I access them to rewire, it is normal to test each one first, if two are bad, they all get replaced.
The OEM wire does not last forever, the flexing at door joints or abrasion points can break and/or short them, corrosion can and does develop at splices and junctions, the cost is cheap and gives consistently better quality work to run new speaker wires.

origional speakers can be used but I dont recomend it, the cheapest speakers you can get today will sounds better then the origionals, plus the fact that the old ones can blow out much easyer. ask me how i know :eek: :D

Years ago I used to hang around with the guys that were big into stereo gear, and I've seen a couple of them blow their amps because they didn't match speaker impeadance with their amps. Now these guys did make their gear work hard for competitions and the like, and always insisted speaker matching was important.
Of course my puny system wasn't matched, and I never did have any problems.

Just thought I'd mention it.