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fuse 4 and 5

Started by w116john, 21 May 2018, 05:00 PM

w116john

hi all

i just got my car back from having some rust repair to the rear end. the car was away about 10 months not due to the extent of the repairs but to the whims of the repairer.
while the car was away i had the time to buy a few original parts to replace some non standard ones i had on the car a bosch fuel pump, coil and some rubber hoses and a few check valves.

i got the car back from a service to recommission it and noticed that fuse 5 was blown ( i had no rear right light or license plate lights) i found a few spare fuses and replaced it but it blew again,  disconnected the license plate light and then it didnt blow so i know where that fault is.

now  to fuse 4, i decided i would put in the new coil, i was careful to connect it properly car started fine but when i put it in drive the rev counter stops, i have no indicators etc, fuse 4 blown.

it is the correct modern bosch yellow coil, i have't had a blown fuse since i bought this car 5 years ago.

i don't think the 2 issues are related fuse 5 is due to the body work at the back and fuse 4 must be due to me changing the coil.


any advice welcome

john


rumb

This may not be very helpful, my W108 shorted at the license plate light and it melted the entire wire harness from there all the way up to the main connection under the drivers side of the dash.  Take out you license light harness and check all the wires going forward from there. btw that license plate lights and harness is still available new for very reasonable price for a W116.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

w116john

thanks rumb

i had a quick look yesterday i removed the lights and holders and cleaned them,  the cable was good at both ends its the middle bit i could not see, even when i took out the trunk lock, i might get a chance tomorow to see if i can get at it.

all the best

ptashek

In case you don't have it, here's the wiring diagram for a 450, with some details. It's from 1974, so same year as your car if I remember right? I'd check each circuit in sequence, disconnecting everything and then reconnecting until the fuse blows.

https://forum.w116.org/mechanicals/euro-wiring-diagram-in-english/msg126476/#msg126476

I've had an issue with fuse #3 on my 280TE recently, followed the same procedure and found the culprit after a few hours and several blown fuses.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

w116john

thanks lukas

i was just checking it there, and i disconected both the rear lights and its now not blowing the fuse, so its something i did yesterday with the rear lights. i will connect one cluster and see if i can isolate it further.

the lights are not sealed well after the repair there was some water in the back of the lights, do you know if the rear light seals are still available?

best
john

rumb

The seals should still be available.  Here is a video on how to reinstall them.

https://www.youtube.com/watch?v=A9K3HkJbELk
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

w116john

thanks guys

i have had no further problems with the tach i must have just shorted something as i was messing with the lights.

i think i will try and get some new light seals as the rear of the car is in pretty good shape now its probably a good time to do it.

happy motoring

john