1977 450 SL mystery cruise control set up - PeachParts Mercedes-Benz Forum

meltedpanda · #1 03-26-2009, 09:16 PM

anyone familiar with what I think is a philco cruise control system . Has a teleflex cable and thottle actuator, at least I think that is what it is. I thought all MB's had the VDO but this is a strange set up, two vacuum lines one line to the manifold the other traced to the area above the brake pedal , just hanging there. Any one have a set up like this that can post a schematic or explain it. I am begining to think it is aftermarket dealer add????

79Mercy · #2 03-26-2009, 09:47 PM

It should have a VDO cruise control system.

Does your cruise system work?

meltedpanda · #3 03-27-2009, 08:38 AM

No it does not work, I know that is the deal, I think it is an attempt at the aftermarket Set up or retrofitting this system instead of the VDO. The "set" is the lever on the steering column. I thought all the Philco set ups had a switch on the console.
I cant seem to find any information on the philco system???

winecountryone · #4 03-27-2009, 10:08 AM

The philco system was used on the early models,up to I thought about 75/76.There was a switch to activate it that you "pulled" which was located next to the A/C controls in the center dash under the radio.there was no lever to change the speed or a resume function.I know both systems are covered on my 107 Service CD,but I need to locate it!(probably in a box that is in storage)
My 1974 model appeared to be missing most of the under hood components,
so I removed the switch when I replaced the non-working fan switch.
There are a number of 70's model sedans I have seen recently around here with this older setup.If you knew you needed a specific part or wiring I could probably locate it.I wasn't the least bit interested in trying to get it to work on my car as I personally hate the damn things!

winecountryone · #5 03-27-2009, 10:40 AM

According to a California company that rebuilds the later VDO systems,the philco was used until 1975.I found a photo of a philco control unit but don't know how to "attach" it here.The seller indicated that this was a "dealer installed option"
Perhaps they had some older parts laying around,and it was retro-fitted after the car was purchased by a dealer at some point???

winecountryone · #6 03-27-2009, 10:44 AM

The early model VDO cruise units were a vacuum actuated motor with a 10 pin amplifier module.This is what would have been "stock" if it had cruise from the factory in 77.This vacuum system was used until 1981.

meltedpanda · #7 03-27-2009, 10:53 AM

yup that is my feeling this unit should not be on this car, I am hoping someone with a 77 can verify. There is no intent to get it going, just trying to understand why its there?

meltedpanda · #8 03-28-2009, 06:03 PM

anyone know where I can find a schematic for this system , what vacuum lines go where?? I have searched till I'm nearly blind, I even have the MB manuals , but no mention of this kind of system. It has two lines , one to the main vacuum input off manifold the other is hanging loose just above the brake pedal??

rowdie · #9 03-29-2009, 02:04 PM

Do you have the Haynes around somewhere? It is on page 151 &152.

meltedpanda · #10 03-29-2009, 09:29 PM

Hmm, I dont think I have that one, does it show where the lines terminate??

meltedpanda · #11 03-31-2009, 10:15 AM

Rowdie sent me some info from a Haynes, and I thought, if the Haynes manual has it then it must have come from an MB source, Sooooo i dusted off some old service manuals and found it!

This is what is known as a “second version “ of the philco system, the first had the push pull on /off on the center dash and the second has the column on/off. This system was only used , as far as I can tell from mid 76 to early 77. Probably not a heck of a lot of them around
Tests
Throttle actuator:
Pull off plug , put ohm meter between poles – should read 10-22 ohms – if not the actuator is bad

Vacuum
Line that has solid brass like connection – this is vent line – from what I can tell it vents to atmosphere.’
The other goes to vacuum source
To test this , pull off throttle actuator – connect to vacuum tester , run engine, and accelerate, briefly , if the gauge drops to zero you have a vacuum leak somewhere, this uses same vacuum supply as CENTRAL LOCKING AND the same VACUUM Reservoir.
I also have the tests for the electrical system. At least I can sleep tonight