Author Topic: dash reassembly questions  (Read 7353 times)

Joe

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dash reassembly questions
« on: June 11, 2003, 12:42:32 »
1. What is the order of replacement of the tach, speedo and center guages?
2. The center guages are connected with a large thick grey cable, which connects to one of the connections under the dash. Is it the one nearest the firewall or the one nearest the steering wheel?
3. Where does the loose brown wire with the circular connector attached go? I recall it connected to the rear of one of the guages, but forgot which one.
Every day is a new day when you're over 50.
Thanks!
Joe

Naj ✝︎

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Re: dash reassembly questions
« Reply #1 on: June 12, 2003, 01:47:43 »
Joe,
On a right hand drive car, the order is tacho, instruments, speedo.I suspect it is the same on left hand drive cars as to need the aperture to fit the oil line. The brown wires are ground wires for the instrument lights on the tacho and speedo.
The instrument harness plugs onto a bracket which also holds the flasher unit.

naj
'Kloines Scheisserle'
65 230SL
68 280SL
68 280SL

ja17

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Re: dash reassembly questions
« Reply #2 on: June 12, 2003, 06:33:27 »
Hello Joe,
The brown wires with the ring terminal on the end hooks under the knurled thumb screw which hold the bracket which holds the guages in place. The instruments's light bulbs will not illuminate without this ground wire hooked up.

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Joe

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Re: dash reassembly questions
« Reply #3 on: June 12, 2003, 08:01:29 »
Thanks a lot, guys!
Some clarification, please.
Is there more than one ground wire to these three guages? I thought there was just one and it goes to the center guages.
The grey wiring harness from the center guages goes to a bracket that attaches to the underside of the dash. There is another wiring harness, black, with an identical connector which also attaches to this bracket, beside the other connector. This is a 1965 Euro 230SL.
I shouldn't have disconnected both of these connectors; now I can't remember which goes where.
Am I really supposed to connect the tach by putting my hand and arm through that maze from below?
Joe

Richard Madison

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Re: dash reassembly questions
« Reply #4 on: June 12, 2003, 09:22:29 »
On a LHD drive car, the speedo is accessible only by reaching across  and behind where the other gauges go, so the order to install is speedo first, then center cluster, then tach.

Both the speedo and the tach have a ground wire with a ring terminal that goes on the center post over the bracket and under the knurled holding nut. The tach bracket is installed from underneath thru the maze while you rest your head on the brake pedal mumbling cuss words about convenient design...
Richard M
1969 280 SL, Tunis Beige, Euro Model (Italy).

Joe

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Re: dash reassembly questions
« Reply #5 on: June 12, 2003, 13:42:02 »
Well, I fished around and found toulouse brown wires with the loop connectors lurking in the mishmash behind the dash. I assume one goes to the speedo and the other to the tach, and the center guage ground is contained in the grey harness.
Is this correct, or is there a separate ground wire for the center guages?
I hope to get it all together tonight.
Gracias,
Jose

Richard Madison

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Re: dash reassembly questions
« Reply #6 on: June 12, 2003, 14:48:47 »
The center gauge does not have a ground wire.
Don't forget the wires that power the tach and speedo light bulbs...a thin covered wire that has some open twisted wires then another two inches of wire with an open wire end....each of these "ends" goes through a small post on top of each bulb socket on the speedo and on the tach.
Richard M
1969 280 SL, Tunis Beige, Euro Model (Italy).

Joe

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Re: dash reassembly questions
« Reply #7 on: June 13, 2003, 11:13:03 »
Well, this has been a comedy of errors. First, I mounted the speedo in the tach hole. Fit just perfect. After discovering this error, I started with the speedo in its right hole, then the center guages, then the tach. The tach was, by far, the worst. At one point, my hand was stuck between two sharp things under the dash, and I could not get it out. Felt like the hiker who cut his arm off the other day.
This project all started when I got this car about 6 weeks ago. I bought it sight unseen in California and a friend trailered it to me in Colorado. We unloaded it in the alley and I drove it into the back yard, where it remains. The ignition switch was shot, so driving it was not feasible because constant pressure had to be kept on the key.
Of course, to get to the ignition switch, the speedo had to come out. And to get the speedo out, the other guages had to come out. Someone had removed the right half of the dash wood, which was in terrible shape, so I decided I might as well finish this job. One of the heater control cables had been disconnected, and the other three control wheels did not operate freely, so that meant this was the right time to fix these problems.
Getting the parts out was fairly easy. I work on a lot of motorcycles, where space is Really restricted, and thought this wasn't bad at all.
I found that the arm on the left heater flap had broken off, so I figured I might as well remove the heater core and have it checked. It was OK, but one of its mounts had broken loose from the solder. This is not uncommon, I understand.
I tested the heater fan by connecting wires from the battery, and it worked ok, so I didn't go to the trouble of dismantling it. Put the core and heater box back in. Put in a new flap. Refinished the wood, and it looked terrific. That is, until I got it in the car, and found the wood was too light, not enough contrast with the cognac dash material. I should have stained the wood much darker. Gonna live with it like it is. Lesson: stain a piece of scrap wood and see how the color looks in the car before proceeding.
Dismantled the heater control wheels and cleaned them up. They were pretty filthy, and some dishwashing soap and a bristle brush did the trick.
Replaced all the dash lights. At least, I think I got them all. Put heater control wheels back in. Lesson: Connect the cables before putting the wheel assembly into the dash. Then adjust the cables after tightening up the assembly. It is a heck of a lot easier to find the little holes in the connectors when you can see them.
Back to the speedo, etc. Connected the cable to the speedo and got it mounted, with ground wire attached to the back. Got the center guages in easily. They sure do look nice with the clean glass and new gaskets. Then the tach. Here's where I had to do resort to some words I normally don't use. The hard part was getting the ground wire to stay on the thread rod while I put the knurled nut on. The ground wire just kept bouncing off. It took most of an hour, but I finally got it together. Hooray! Lesson: remove the short flex hose that carries side window defrost air and remove it. Kneel on the ground (or floor if you're inside), and use your left hand to assemble the back of the tach. The flex hose is easy to put back in place, and its absence gives a lot more room for your hand and arm.
Hooked up the water hoses to the heater core and the oil pressure line, and started the car. Started right up and sounded great. Then I noticed the speedo needle was moving and tach was not. Since the car was on the ground, this was something remarkable.
So, how much money did those darn engineers save in 1965 by using the same size nut to attach the tach and speedo cables? Looking back, I was foolish to get the cables mixed up, but that's part of growing old. Anyway, out came the tach. Out came the center guages. Out came the speedo. Back went the speedo, etc. Only took about a half hour to do it all.
Started it up, and the tach works now. Murmured hooray.
Now a new problem. Well, two. The dash lights do not work. The red light in the center guages stays on when the car is running. I put a volt meter across the battery poles and got 12 volts even when revving the engine. Then I noticed the generator has been replaced with an alternator.
Now to sort this one out. Any advice on the dash lights and red light are appreciated. I did turn the rheostat knob on the center guages, to no avail.
Oh, yes, another one. The heater fan makes a scraping noise. I can let that go till autumn, but if there is a fix short of removal, I'd like to know it. Can't imagine that right now.
I was going on my maiden ride tomorrow. Guess I may have to carry a spare battery in the boot.
Joe