300SDL STRANGE and sudden?!! - PeachParts Mercedes-Benz Forum

cifp48 · #1 10-26-2004, 02:50 AM

Hi all,

I have not been here in a looooong time!!

I was driving my 87 3000SDL a couple of days ago on the freeway @ 65-75 miles. Stopped @ a gas station for some snacks, no fuel. Started the car and started getting hot, real hot air from Defrost vents, drove for about 40 miles home, still same problem. The following day, checked fuses, NO 5 fuse was fused! replaced with the spare one in the fuse box, as soon as I turned the car on, heard the climate control kicking in for a sec and same problem again, HOT HOT air thru defrost vents.

Checked the fuse, same fuse blown again, made a huge mark. I wonder if the fuse is old or there is something wrong???

Please help!!

Thanks in advance.
Mehdi
1987 300 SDL with 99k miles

cifp48 · #2 10-26-2004, 03:11 AM

Searched but could not find any info????

P.E.Haiges · #3 10-26-2004, 10:01 AM

cifp48,

Sounds like the fuses are doing their job: Opening the circuit that is drawing too much current.

I would start by getting a wiring diagram to see what is on the circuit that is drawing too much current. Then disconnecting probable problem componants.
You might disconnect the fan first if it is in that circuit because the fan is a likely candidate.

P E H

TX76513 · #4 10-26-2004, 10:16 AM

You probably have 1 of 2 things going on. If your aux. water pump went out (common) it will blow #5 fuse. Disconnect pump and replace fuse - if all is well replace aux. water pump. Check the AC Clutch (do a search) to determine it's health. Unfortunately (experience) if the clutch goes out it usually takes out the ACC Controller

. I managed to do some DIY repairs to mine (acc controler) - and all is well +30 days now.

Good Luck

cifp48 · #5 10-26-2004, 12:22 PM

Thank you all for the replies.

Any idea where I can get a wiring diagram from??

Thanks
Mehdi

BTW, before this problem, The A/C would never shutoff, it kept on blowing air through the defrost vents, I could change the temp (hot or cold) but the system would never turn off, and the air would blow only from the defrost vents.

cifp48 · #6 10-26-2004, 12:50 PM

I have also noticed that sometimes when I unlock the doors, the alarm goes off and the Transmission shift with a jerk from 1-2 & 2-3??

ANy suggestions on these?

Mehdi

TX76513 · #7 10-26-2004, 01:34 PM

CIPF48 sent you a P Email with some links and information.

cifp48 · #8 10-26-2004, 03:41 PM

Thanks will go into it.

I cant seem to get the a/c to work at all either, ie the air does not blow at all, only when I am driving the defrost vents draw HOT really HOT air, I cant seem to press the circulate button either??

any suggestions??

TX76513 · #9 10-26-2004, 04:08 PM

Quote:

Originally Posted by cifp48

Thanks will go into it.

I cant seem to get the a/c to work at all either, ie the air does not blow at all, only when I am driving the defrost vents draw HOT really HOT air, I cant seem to press the circulate button either??

any suggestions??

IMHO that sounds like the ACC Controller - as it defaults to hot when it fails. If I am all wet with this idea someone will chime in

cifp48 · #10 10-26-2004, 10:00 PM

But U see, it was blowing cold air all the time, it would not turn off. But now, the Fuse #5 is burnt, and keeps blowing as soon as I put a new one.

cifp48 · #11 10-27-2004, 07:41 AM

Any other suggestions??

TX76513 · #12 10-27-2004, 09:14 AM

I have PM you some links for diagnosis. I found that a towell across the defrost vent helps until the repair is completed

Been there done this.

cifp48 · #13 10-27-2004, 01:50 PM

I wet towel to cool!!!!!?

boneheaddoctor · #14 10-27-2004, 01:54 PM

Quote:

Originally Posted by cifp48

I wet towel to cool!!!!!?

I will guess a dry towel to block the airflow. Wet towel is not good for the interior.

cifp48 · #15 10-27-2004, 02:39 PM

Thanks to everyone who has given their input so far. Will try these things and post feedback!!

ANy more suggestins would be very much appreciated.

Mehdi