cruise control intermittent

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cruise control intermittent

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cruise control intermittent - 12/9/2005 6:12:13 PM

lldanj

Posts: 2
Joined: 12/9/2005
Status: offline

I'm surprised I didn't find more posts about cruise control on a 300D. Mine works intermittently, less than 10% of the time. Any suggestions on how to diagnose and fix it?

I have never removed the instrument cluster and am a bit nervous doing so. I'm not a very experienced mechanic.

_____________________________

Dan R.
1984 300D running on waste veg oil
Vegcar.net

Post #: 1

RE: cruise control intermittent - 12/9/2005 9:15:26 PM

Benzbob

Posts: 151
Joined: 2/25/2005
Status: offline

Your cruise amp is likely the cause, very very common problem with MB cruise control!

A new cruise amp will run $300 +, however, many elect to repair corroded solder leads as this is the more common cause for failure.

_____________________________

87 300 D

(in reply to lldanj)

Post #: 2

RE: cruise control intermittent - 1/2/2006 8:54:23 AM

Pizzaman

Posts: 2
Joined: 1/2/2006
Status: offline

They had a method of wave soldering (during manufacturing of the board) for electronics in those days that lent itself to creating devices with poor solder joints after a while. It didn't only occur with mercedes but with the electonics of many car manufacturers. Anyway BenzBob is correct about this and the solution usually is to remove the cruise amplifier (under dash near parking brake) and disassemble the case and resolder all the connections on the board. This is very tedious work and if not done correctly will render the cruise amp useless. Should only be attempted with correct soldering equiptment and some experience with soldering. I fixed both the cruise and heater controls on my 83 CD Turbo with this method and it was very satisfying.

(in reply to lldanj)

Post #: 3

RE: cruise control intermittent - 1/20/2006 1:05:19 PM

steelerman

Posts: 15
Joined: 11/25/2005
From: nelwoody@sbcglobal.net
Status: offline

I have a 1987 300TD and have had the same problem with the cruise control. The manual I have says that the problem is in the 16 prong connector behind the instrument panel. This can be removed with a 3/32 dia. wire with a 90 degree bend on one end, about 1/8 long and a wood handle attached to the other end, make two, insert on each side of instrument panel and pull intil unit pops out. You will have to insert the two wires so that the 1/8 bend is longitudinal with the insert space and after passing thru. , turn the wire 90 degrees. I need to due this as soon as the weather breaks and time permit. The manual also states that after diconnecting the connector, clean up all 16 pins and reconnect, if this doesn't solve the problem, replace the connector. Hope this kelps you out, respectfully Steelerman.

(in reply to lldanj)

Post #: 4

RE: cruise control intermittent - 1/22/2006 1:51:10 PM

Benzbob

Posts: 151
Joined: 2/25/2005
Status: offline

< Message edited by Benzbob -- 1/22/2006 1:54:36 PM >

_____________________________

87 300 D

(in reply to lldanj)

Post #: 5

RE: cruise control intermittent - 1/22/2006 1:58:07 PM

Benzbob

Posts: 151
Joined: 2/25/2005
Status: offline

quote:

ORIGINAL: steelerman

I have a 1987 300TD and have had the same problem with the cruise control. The manual I have says that the problem is in the 16 prong connector behind the instrument panel. This can be removed with a 3/32 dia. wire with a 90 degree bend on one end, about 1/8 long and a wood handle attached to the other end, make two, insert on each side of instrument panel and pull intil unit pops out. You will have to insert the two wires so that the 1/8 bend is longitudinal with the insert space and after passing thru. , turn the wire 90 degrees. I need to due this as soon as the weather breaks and time permit. The manual also states that after diconnecting the connector, clean up all 16 pins and reconnect, if this doesn't solve the problem, replace the connector. Hope this kelps you out, respectfully Steelerman.

An easier way to access the Cruise amp for the 87 124 is to remove the knee bolster below the steering wheel, it's right behind there!

_____________________________

87 300 D

(in reply to steelerman)

Post #: 6

RE: cruise control intermittent - 2/3/2006 4:07:06 PM

jarrett

Posts: 4
Joined: 4/4/2005
From: tampa
Status: offline

lldanj-I had a 87 with this problem. I went to the dealer and bought an amplefier, installed it and it didn't work. I later found out that this was indeed the problem but some replacement parts have an extra pin hole so this has to be addressed. I forget if the male or female has the extra attaching point but there is a service flyer addressing this. Also, the dash module just sort of wiggles out. It has like a large thick rubber band around the panel and it just pushes in and pulls out. Be careful once it is loose as the connections are short and you could damage the connections.

(in reply to lldanj)

Post #: 7