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1983 300D Turbo
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120 Posts
Discussion Starter #1
I've misplaced my fuse box cover & due to my recenct and hasty separation from the mrs. I have no idea where it ended up!

I know I saw a pic of the inside of the cover on this forum but I'll be damed if I can find it now that I realy need it. Help please!

I blew a couple of fuses over a week but now the blow as soon as I put them in.
I know the horn and the glow plug buzzer are connceted to it.

Any pointers on tracking down the source of the short would be appreciated as well.

many thanks!
 

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85 300D
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390 Posts
I would say your biggest culprits would be the MONO valve and the auz water pump. They each have a quick disconnect Unplug them and cross yoru fingers as you put in a new fuse. My MONO valve connection was melted when I bought my car!
 

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'82 300D
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1,279 Posts
Put a 1 amp in line fuse on the aux water pump line. When the aux water pump locks up, it usually fries the ACC as well.
 

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1983 300D Turbo
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120 Posts
Discussion Starter #6
I recall one part that directs antifreeze to the heater core. I assume that is the heating water valve. am I rightÉ

also where is the auxiliray water pumpÉ

also, I see that this fuse is also connected to the Èoverload protection for the automatic transmissionÈ Ive recently been messing around with a hard shifting tranny and Ive disconnected the bowden cable + Ive played around with the vacuum control valve. can csomeone point me to the Èoverload protectionÈ

usual thanks!!
BTW Ièm working on a french keyuboard so É is a question mark, è is an apostrophe and È is a quotation mark!!
 

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85 300D
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390 Posts
LOL, I was wondering about that!!

The "Heating control valve" is the MONO valve, found on your firewall next to your battery. One hose in the bottom, one out the side, and an electrical connection on the top.

The "Water pump" is a small water pump that pumps coolant to the heater core when the engine is at low load and the heat is on. It does that so you have adequate flow to your heater when it's idleing and such.

Aux. Fan is on the front of your radiator to help cool when the coolant temp get's too high (like 96*C or something?)

Hope that helps, they are most likely your culprits.
 

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W-1-2-3 Go!
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16,161 Posts
rrgrassi said:
Put a 1 amp in line fuse on the aux water pump line. When the aux water pump locks up, it usually fries the ACC as well.
Isn't this what fuse 14 is for?
 

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1983 300D Turbo
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120 Posts
Discussion Starter #9
I may have found the Fuse 14 problem... But what next?

Fuse 14 still instantly pops as soon as I turn the key!
I tired disconecting the mono valve, aux pump and fan... still blowing fuses!.
for fun I used my multi meter and found continuity across the two wires that lead to the mono valve... I may be out there but , especially with a blown fuse and the ignition off, that should be an open circuit shouldn't it??
I disconnected the climate control at the console figuring the short to ground might be there but, still blowing fuses!
My friend's son who's an up an coming mechanic, chickened out of digging any further for fear of messing stuff up & recomends I go to an Auto-Electric specialist. (he knows how I feels about benzie & thought better of pushing his luck!!)
So I will try to dig up a specialist next week but in the mean time, any ideas an amateur like me can look at??
 
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