windshield wiper fuse immediately blows out

[Ron Seegars, Sr]

1981 R107 280SL: As soon as I turn the ignition key on, my windshield wiper fuse immediately blows in fuse box ( located passenger floor right side). I have tried a 25 power fuse instead of a 16 just to see if it will blow and it does. Also on another note, my right signal light will not work at anytime. Bulb works but turn signal will not blink. The left one and the two rear work fine with the running lights off. If I turn the headlamps on, neither of the front signal lights will blink but the two rear again work fine. My biggest concern right now is the fuse blowing for windshield wiper but I will welcome any comments on the other electrical problem. Thanks.

[97 SL320]

What is the history of this car? Did you get it with problems or have you had it a while? Any recent work?

The lighting issue is likely a open ground at one of the lights.

For the wipers, you need a wiring diagram to determine what else is on that circuit. I'd unplug the wiper switch / motor and see if the fuse still clears. ( to save a fuse, use a incandescent test light across the fuse holder or a automatic reset circuit breaker. Or, with the fuse holder empty and with key on, _Quickly_ bridge the holder. You just want to determine if a spark is generated from a dead short. If you pause too long, the holder will be damaged from the arc. )

[Ron Seegars, Sr]

Where is the location of the wiper motor plug in? Is it under the dash or can I get to it under the hood on drivers side? I have had the car since 2000 but it stopped running and sat under a carport for 8 to 10 years. I now have it running again and have been driving it for the past month or so. Also on the light issue, I just noticed that when I engage the emergency or hazard flasher - all the lights flash except the right front which is also the non turn signal light. Thanks for you input.

[meltedpanda]

you have to trace wires, you have a short, most likely a bare wire or a plug that is bad. Electrical gremlins take a bit of detective work

[nobby]

Originally Posted by Ron Seegars, Sr

Where is the location of the wiper motor plug in? Is it under the dash

Yup. And it's real fun in there.

Have we discussed getting the correct manuals for your car? Now is a good time.

[Ron Seegars, Sr]

97 SLC320 - You me on to it. I pulled the fuse box out enough to trace wires on #11 fuse holder. Two wires. One was going out to under hood on right side just by battery box. It was grounded to the coolant fill jug. I ungrounded this wire and taped it off and fuse #11 does not blow anymore. Wipers work fine on all three phases. Could this wire possibly be for the washer pump? Fuse #11 states windhield wipers, washer pump, optical horn, and something about headlamp which is worn off id label. Remember I stated that my right front turn signal did not work? Since ungrounding that wire, it now works but the left front turn signal stopped blinking. All lights work until I turn the headlamps on and then the front signals light up but don't blink.

Anyway, I do have working windshield wipers now. Nobby: Where can I buy the proper books for this 1981 280SL R107 with m110 engine even though it has a 380SL trunk badge on it. (WDB vin number grey market). Thanks guys!

[97 SL320]

I'd need to see a wiring diagram to figure this out.

A wire would never be run from a fuse to a ground point if that fuse is on the positive side of power. There is a possibility that fuse 11 power has somehow contacted the ground wire you lifted further back in the harness due to mouse chewed wires , wires burnt together.

" Fuse #11 states windhield wipers, washer pump, optical horn, and something about headlamp which is worn off id label. "

Optical horn would be flash to pass ( pull on the high / low beam lever to blink the headlights on high beam when the lights are off.) For the last one, were headlight washers available on these cars?

[Ron Seegars, Sr]

97 SL320: I do not think that this 280SL has headlight washers, I could be incorrect but don't think so. The wire that I ungrounded did have two or three spots that were chewed or exposed. Mice had chewed three of the spark plug wires over the years which I had to replace. I also get no power to the automatic radio antenna in the trunk. My problem is that when I look at a wiring diagram, I still don't know what I'm looking at. I am a recently retired railroad guy so all this is new to me. Still cannot figure why the right front turn signal started working when I ungrounded this wire but left one stopped. Thanks for all your help.

[rowdie]

Generally if the wire wasn't brown it should not have been grounded. Headlight washer/wipers were an option on Euros then.

Don't think there is a specific manual for the 280SL. For most chassis repairs use the 107 chassis service manual. There is an on line version Model 107 for US models. Use the 380SL as a reference. Paper manuals come up on EBay. There is also a M110 service manual which covers US models that will help. EBay again.

The on line MB Electronic Parts Cataloger (EPC) is a must for Euro owners. EPC-net Online Subscription is free for US residents but it asks for a Credit Card number to prove residency. You can compare part numbers for your model with other models to see if the US model is the same.

[Ron Seegars, Sr]

Thanks for everyone's help.