Temperature gauge not working

[catjim813]

All,  I have a 69 280 sl with the temperature gauge not working after I had a rear main seal placed in the car.   I cannot locate what may or may not be connected, that is causing the problem.  Does anyone have a wiring diagram for the temperature gauge?   Thanks in advance.

[badali]

The temperature gauge is a capillary tube.  If your engine was pulled to do the job they may have broken the tube.  This is an expensive mistake.  I'm not sure what they cost today.  A few hundred $$$

[ctaylor738]

Just to expand on what Brad said.  There is no wiring.  The capillary tube runs from a screw-in fitting on the left front of the engine back through the firewall and then to the gauge.  The fitting, tube and gauge are all one piece. 

To replace it, you need to drain some coolant, remove the engine fitting, remove the gauge cluster (after removing the steering wheel and tach), and thread the tube through the firewall (removing the firewall grommet) and out through the hole for the cluster.  Then you remove the gauge from the cluster and install the new gauge/tube/fitting and re-assemble in reverse order.

I bought a rebuilt gauge from benzrestorer on ebay.

You can go after the shop on this, of course.  But with age, the tube gets really brittle where it attaches to the engine fitting and it's tough to get it out without damaging it.

[ja17]

As mentioned, often times age, brittleness and previous abuse, is the real culprit. You can also look into having yours repaired, this is costly also. A gauge from a finback sedan of the era works fine and looks exactly the same with a very minor modification.

[catjim813]

Thanks to all,  I can clearly see the damage on the portion connected to the block.  UGGGHH   I finally got the oil leak repaired.    Well I my winter projects just moved this one to the top of the list.  Injection pump repair and this repair should have me ready for spring.   Thanks for all the quick replies.

[wwheeler]

I had my temp gauge fitted with a new tube from a well know vendor and it works very well. I was having all of the gauges rebuilt and they did this even though the old one was working. I was worried about the brittleness when reinstalling as well. You have to pull the gauge and send it off and shouldn't be a big deal. Will cost $$$ but don't remember exactly how much.

[WRe]

Hi,
it's possible but not easy to repair the temperature gauge, see here:
- http://w113.eu/geschlossen/Reparaturen/Wasserthermometer%20reparieren%20Mercedes%20Pagode%20W113.htm
- http://www.170v.de/yabbfiles/Attachm...ometer_001.pdf .
...WRe

[catjim813]

Does any one know of vendors in the US who can repair the capillary tube or have a used one for sell?

[ctaylor738]

Palo Alto Speedometer for repair or benzrestorer on ebay for new ones.

[wwheeler]

Palo Alto did my gauges on the W111. Temp gauge works well and the speedo is so smooth it is scary. 

[catjim813]

Spoke with the team at Palo Alto today looks like that's where I will be shipping my gauge thanks to all for the replies.  Once I get it back I will update the group.