I recently did some work on the 300TD. I painted the gauge needles so I had the instrument cluster apart and put it back together. The car drove with no problems. the next time I took it out to drive to work the #2 fuse blew and the the #6 fuse. I replaced both fuses and now the #2 fuse blows if I turn on the turn signals. I took out the Inst. Cluster and the #2 fuse still blew so I ruled out anything related to the work I did when I painted the gauges. Then I found the passenger tail light half full of water so I repaired the bulb holder and now it is working again. The hazard flashers work so I think all the wiring is good to the lights. I also disconnected the power antenna and that had no effect. I replaced the Hazard switch and that wasn't the problem. The next thing I will try is replacing the turn signal relay for another $40 but the old one looks fine inside. There is an IC chip in it and maybe that is the source of the problem. I will let you know what happens when I replace it. ANY OTHER SUGGESTIONS? I ordered a Short circuit tester from Amazon to help diagnose the problem but I don't relish the thought of trying to find a short between the Inst. cluster and the flasher relay. All the wires are so inaccessible and bundled together. I am not sure where to look next. Any ideas?

So if you use the hazard switch all turn signals work correctly?

Did you take anything off surrounding the steering column during the cluster job?

If you blew two separate fuses then it sounds like something has been pinched maybe the cable with wires coming from the turn signal control located on the steering column.

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1995 E300 Diesel

Thanks for your reply Benedict. If I turn the hazards on all the yellow signal lights work correctly. So I have ruled out the wiring to the signal bulbs. I didn't touch the steering column or the signal arm switch when I removed the instrument cluster. When It first happened it blew the #2 and then the #12 fuses. but if the #12 fuse is removed it still blows the #2 fuse when
I put the turn signal on. I removed the flasher relay from under the center console and then if I put the turn signal on it doesn't blow the #2 fuse but the hazards don't work either obviously because I think it use the flasher relay. I called a local shop and the said they would look at it for $160 but when I told them I had tried to trouble shoot the problem they told me they weren't interested and that it sounded like it would be a headache to fix.

Crickey, $160 to look at it: sounds like Sydney pricing.

Any aftermarket alarm?

It is possible that you have a dud relay flasher as they are electronics which go out of specifications over time due to draining capacitors etc. but that said not all that common to blow a fuse: usually they stop flashing or signal lights get stuck on or flash with inconsistent intervals.

Just go over everything you did right before the signals went faulty.

Any chance you drove a screw through something removing and replacing the dash? Very easy to put in the long screw where the short one should have gone.

If you removed the hazard switch plug did you put it back the wrong way around(presuming that it is possible to do) as in one state it is normally closed and the other normally open.

It can't be a short at the incandescent direction of turn bulb in the dash cluster because you said all is ok when you activate the hazards.

Just a possibility but I presume getting the cluster in and out you may have placed some unusual pressure on the turn signal control?

A used to work with a guy years ago that used a method for fault finding that defies normal logic- he would replace the fuse with a nail and sure enough something somewhere would start smoking. Not recommended.

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1995 E300 Diesel

WHat year is your tdt?

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

The car is a 1985 300TD Estate 123.193
No After market alarm was ever installed as far as I know. I think the hazard switch can only plug in one way because of the pin pattern. I don't think I have any screws that are too long and they are all removed as I have the dash disassembled. The steering column that you mentioned is making me wonder. The car needs front end work and it trashes the tires and causes vibration that gets transferred to the steering column. I was away for seven months and my wife was driving the car as her daily driver and the vibration was quite sever if you got up to sixty MPH. I think I should look at the signal switch wiring as the next possible place where there are exposed connections of wires. From my limited experience with auto electrics if it is a short in the wires it usual occurs where an exposed metal connector grounds out to the body or a wire is pinched and the insulation is breached.

My #2 fuse was blowing too. I cleaned the contacts on the hazard switch and that fixed the problem.

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1981 300TD "The Green Lantern"
1980 300TD
1983 300D Euro "China Cat"

After more trouble shooting and replacing the #8 and #12 fuses as well as the turn signal flasher relay I tracked the problem down to the instrument panel. I thought it wasn't the problem but I didn't realize that the #12 fuse was also blowing and would cause the signal not to work as I was testing it. My initial instinct from working with computer problems in software and hardware was correct. Its is the last thing that was changed in the system that is usually the cause of problems. The last work I did was to the gauges and when I reassembled the instrument panel the turn signal indicator wire got trapped between the grounded metal of the speedometer and the plastic case. The car worked fine the morning after the work I did but after getting warm in the sun the insulation on the pinched wire got soft and made contact with the metal speedometer later that day. The tail light filled with water was a red herring and didn't cause the problem. The turn signal bulb is on the top and didn't get wet. It was good the I discovered it in the process and fitted a generic bulb holder to replace the bottom running light. The drain was blocked again. this time I drilled a small hole in the bottom of the lens so it won't happen again. I also sealed a crack where the lens is glued together at the top where the water was getting in. Here are some photos of the shorted wire and the tail light bulb holder repair with an off the shelf Napa Auto parts bulb holder. I had to drill a hole in the back for it to fit.

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