850 problem, horn and tacho not working.

juggernaught_666 · Post by **juggernaught_666** » 08 Jun 2010, 21:52

Hi everyone, long time reader first time registerer and poster.

I have a Volvo 850 1994, don’t know if it’s a GLE or GLT or SE, don’t think it’s important. I have owned this car strait from my grandparents from 2006.

The problems I have I think are all related, eg wiring under dash.

Problem 1, solved itself, but here it is anyway: cruise control stopped working.

Problem 2, I rarely use my horn so I don’t know when it stopped working, but went to use it the other day and there was no sound, checked fuse but it was ok.

Problem 3 tacho sits at zero, occasionally (once a month) it works for a short time then returns to zero, Problem noticed since early December (before rego check) last year.

Problem 4, Speedo didn’t work for a day, but solved itself, after I fiddled with some loose wire plugs under the dash, mainly the red hinge one.

I believe its loose wires, as all the problems have occurred in the past (except for the horn) and I have fixed them by disconnecting/refitting some of the loose wires, even just giving them a wiggle. Another reason I think it’s the red wire hinge plug or somewhere close to it as when that is loose, and you wiggle it some of the dash lights (abs, engine check, hand brake, etc) go out.

Has anyone had the same or similar problems?

All help would be much appreciated!

Thanks in advance.

Post by **Ozark Lee** » 08 Jun 2010, 22:17

Welcome to MVS,

For problem 2, check to see if the horns are even plugged in. The horn switch on 850s is a known problem where the insulator breaks down and the horn gets stuck on. May folks just unplug the horns and forget about it.

You can get a repair kit from http://www.odometergears.com if that turns out of be your situation.

Problem 3 sounds like either a problem with the wiring to the instrument cluster or the instrument cluster itself. The RPM sensor is vital to the car actually running so it sounds like it is working but the signal isn't getting passed along to the cluster.

Problem 4 is much like problem 3. Wiring problems are a real bear to track down but they are easy to fix once you find them. You just need to go after things with a VOM from one end or the other and trace stuff to or from the source.

Describe the red plug a bit more or post a picture, it could be that one of the ZIF sockets under the dash is not properly seated.

Good luck,

...Lee

juggernaught_666 · Post by **juggernaught_666** » 09 Jun 2010, 18:42

For problem 2, check to see if the horns are even plugged in. The horn switch on 850s is a known problem where the insulator breaks down and the horn gets stuck on. May folks just unplug the horns and forget about it.
You can get a repair kit from [url=http://www.odometergears.com[url] if that turns out of be your situation.

Will do tonight, forgot compleetly when the tacho started working randomly and still is... I need a horn as 3 times in the past month som idiot has either sat at a set of lights and started texting or some one has not bothered to check over there shoulder/look in their blind spot and ive had to slam and swerve.. repair kit will be final option if nothing else works, i have been told to unplug horns and try in another car...

Problem 3 sounds like either a problem with the wiring to the instrument cluster or the instrument cluster itself. The RPM sensor is vital to the car actually running so it sounds like it is working but the signal isn't getting passed along to the cluster.

that sensor might be on its way out, but it started working on my way home lastnight, so it may also be from a loose one.

Problem 4 is much like problem 3. Wiring problems are a real bear to track down but they are easy to fix once you find them. You just need to go after things with a VOM from one end or the other and trace stuff to or from the source.

that will take some time, might be a weekend job...

Describe the red plug a bit more or post a picture, it could be that one of the ZIF sockets under the dash is not properly seated.

it might be a zif socket... this is the only web image i could find:
http://www.google.com.au/imgres?imgurl= ... s%3Disch:1

on my car a right hand drive car, its between the steering column/rod thing and the outside of the car tucked deep up in the footwell area, there are a white and black one as well they each have abut 60 wires comming off them and they are all mounted on the one black metal bracket.. ill try to remember to take a photo tonight.

juggernaught_666 · Post by **juggernaught_666** » 25 Nov 2010, 18:56

Progress Report...

Tacho works 80% of the time after repacing the eletrical side of the ignition switch. It does occasionally bounce around both above and below the level i think it would be reving at.

Horn is not working, have been told to pull out the dash, I would like more advice on what I should do both before and during this major operation, and what exactly im looking for.

Thanks