First off, howdy all, as this is my first post, after lurking a bit, and reading/searching around. This looks like a really active forum, with lots of knowledgable folks contributing.

Background: I am a relatively new fan of diesels, and merc diesels in particular. A friend of mine converted an 85 300TD to run SVO, and got me hooked. We are both "project car" type thinkers, so we jumped at a chance to buy a package deal from a local seller: a very rusty and not-PA-inspectable 77 240D with a 4 speed manual and a working but slightly tired engine, and an 83 240D with an automatic trans, and a rebuilt-but-not-finished engine, with over $1000 worth of machine work into the engine. The seller had already done quite a bit of tear-down on the 83 chassis, including taking the doors apart to figure out the vacuum locking problems, and why the electric windows weren't working. The entire engine bay had been emptied out, and the rebuilt core of the engine (sealed up and rebuilt from oil pan to valve cover, but needing all other parts put back together) put back on the mounts. We don't have any contact with the seller any more, as he moved, and we have lost track of him.

Money is drum-head tight for both of us, so we decided to transplant the working 77 engine into the 83 body, get it running, drive it for a while, and finish the work on the rebuilt 83 motor, and eventually transplant it back into the 83 body. We parked the cars side by side, and found a few differences, but nothing that seemed critical enough to stop the project.

We have successfully transplanted the 77 motor into the 83, and have things running and driving.

However, a few issues remain. Here is a list of all the problems, and a bit more information to go with them. I don't know of these are individual problems, or all tied together.

1. No brake lights when pedal pressed (tail running lights, turn signal lights, and backup lights all work properly)
2. No fog lights (At least one of the bulbs is known-good, and headlights work fine, high and low beam)
3. Fuel gauge registers empty, and no reserve warning light (bulb checks okay though), with a 1/2 tank of fuel
4. Temp gauge doesn't register any temp, even with engine at normal operating temps, and thermostat cycling normally

We haven't figured out the vaccuum locks, or the electric windows, but we haven't even started to evaluate them. the vaccuum system seems to be working okay, as we have no trouble shutting off the motor, and the HVAC system (Well, minus the AC portion) works fine.

Here is my "big clue"... There is a 14 pin connector hanging free under the drivers side dash. The car was equipped with cruise control, but there appears to be only one "large silver box packed with electronics" under the drivers side dash, and it is already connected, with a 10 or 12 pin connector. Am I missing some kind of relay or control module that would tie all these problems together? I have checked the more obvious stuff, like connections behind the dash, bulbs, fuses, clean accessable connections. The charging system seems to be working fine, running at about 14.02v , and the battery is new.

Whew. Okay... I can answer any more questions you have, and would welcome advice and input on trouble shooting things.

-Matt

The instrument/combo switch/dash wiring harness probably has a different pinout. I would think most of those issues would be covered by that. Find the electrical diagrams in the FSM and start your debugging. Chances of fixing climate control == nil unless you transplant that as well.

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Is the 14 pin connector round?

__________________
'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

Nope, the 14 pin connector is 7 long by 2 wide. The round connector, not sure of how many pins, is the one that goes on the back of the gauge cluster. It was/is connected, and everything else, including the cluster illumination lights (after a rheostat replacement) work just fine. The clock, speedo, odo, all indicator lights and oil pressure gauge are fine.

-Matt

It sounds like you are suggesting that as a result of the transplant things don't match up? Possible, although the only thing that was changed during the transplant was the motor itself, and all accesories. All vaccuum connections were properly connected back up, and electrical stuff seemed to connect back okay. The only electrical connections made as part of the transplant was starter, ground strap, alternator charging circut, glow plug harness, and the temp sensor, which is a single conductor round plug type, bundled with the glow plug harness. We also added a 110v block heater, but that isn't part of the vehicles electrical system.

-Matt

There are two 14-pin connectors under the drivers side dash in my car. One is for the cruise control and the other for the lights. There are two control modules - warning and cruise control. You might be missing your cruise module.
I dont see how that could affect the 4 problems you mentioned. Checked the fuses lately?

__________________
'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

Yup, all fuses present and accounted for. And more importantly, not blown.

Of the two modules under your dash, where are they physically located? I have one smaller module mounted very close to the top of the emergency brake pedal. The 14 pin connector is hanging down just to the left of the brake pedal, and there appears to be mounting holes of some kind above the brake pedal, on what appears to be part of the steering column.

-Matt

Regarding the brake lights, the switch is mounted under dash on the pedal support. With the key on, you should have twelve volts to one wire at the switch, no volts to other wire until the pedal is depressed. Easily verified with a non powered test light. Fog lights operate by pulling out on the headlight switch while low beams are on. Temp gauges usually read minimum temp with a disconnected wire and max temperature when the wire is shorted to ground.

__________________
81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

Yup, thats where the cruise module should be. You're missing the cruise module. Check around that area for the brake switch too.

__________________
'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

I have transplanted later engines into early bodies and visa a versa and maybe I was just lucky but I've not run into problems like you describe. #4 problem concerning the temp sensor which could be because the early 616s had two sensors in the head (GP relay, I think and cabin gauge) and the later cars had only one, for your cabin gauge. Hope this helps

Check your grounds which you prolly already did,

Edit..Noticed you are talking 617, but I would think the temp sensor would apply.

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Hrm, okay, well that combined with an earlier post, I think I can check the connection from the sensor to the gauge by just shorting out the lead from the senser, and checking if the gauge goes to high temp.

I am missing the cruise control amp, as was pointed out in a post above, but is anything else routed through that, such as brake lights, or something, that would cause them to not function without the amp in place?

I am going out to work on the car this evening a bit, and I will have a chance to check the temp gauge thing, and test the brake pedal switch.

Anyone out there got a cruise amp module they would part with? I don't plan on getting the cruise contorl working again, so I don't care if the amp works correctly, it just needs to be there to complete the circut (I think).

-Matt

Well, I DIDN'T make it out there last night, and prolly good I didn't try... temps are in the teens at night around here, and working in an unheated, uninsulated garage would be pretty hard on the ole digits... course this weekend it is supposed to settle into the single digits at night, so I was thinking of going out and trying a cold start test =)

Had another thought. Howabout I go take some pictures of a few "questions" I have, such as a few connectors that look like they need a place to connect, and such... Would it be helpful to post them here, and have a few folks who have 123.123 chassis to look at em? Won't take the time if folks don't think it is worth it, but I can take pretty good quality, well-lit pictures in that garage.

-Matt