Dash gone crazy

An alchemy of sparks, copper wire and earth

Moderators: User administrators, Moderators

Post Reply
User avatar
BertieWells
Registered user
Posts: 202
Joined: 27 Mar 2014, 14:03
80-90 Mem No: 13372
Location: Wrexham, North Wales

Dash gone crazy

Post by BertieWells »

Ok guys here is one for you to scratch your heads about.

I had the clocks open to check to see if a voltage could be measured fromthe green wire (tacho) to ground.

Put the dash half back together and this:
ignition off headlights on
Dash lights come on
Oil light comes on very dim
Indicator light wont work (thats always been intermittant)
Handbrake light wont work
Ignition on headlights on
Dash lights on very dim
Handbrake light randomly started working (not with ignition change)
Indicator light wont work
Turn lights off and the initial flashing temp light flashes for ever
Start the engine
Dash warning lights lights go out
temp light eventually stops flashing
If i turn lights on then off the temp light will do its flash sequence again.

Left it for a while came back and everything seemed to work.

Put the clocks back in properly and its back to doing that:(

What the buggery have i done?
1985 1.9 DG

User avatar
marlinowner
Registered user
Posts: 1530
Joined: 28 Jan 2014, 12:02
80-90 Mem No: 13646
Location: Scottish Borders

Re: Dash gone crazy

Post by marlinowner »

If you lose the earth from the dashboard 14 way connector then the gauges etc earth through the lighting circuits. When you turn the lights on that route is lost so the symptoms change.
1993 SA VW T25/T3 2.5i Microbus/homebrew camper
1981/1968 Marlin Kitcar TR6 Engine

User avatar
BertieWells
Registered user
Posts: 202
Joined: 27 Mar 2014, 14:03
80-90 Mem No: 13372
Location: Wrexham, North Wales

Re: Dash gone crazy

Post by BertieWells »

oh ok thanks, ill take a look tomorrow :)
1985 1.9 DG

User avatar
BertieWells
Registered user
Posts: 202
Joined: 27 Mar 2014, 14:03
80-90 Mem No: 13372
Location: Wrexham, North Wales

Re: Dash gone crazy

Post by BertieWells »

Stripped it all apart cleaned up connections as best i could. back together and all seems to be good :)

Rob
1985 1.9 DG

User avatar
BertieWells
Registered user
Posts: 202
Joined: 27 Mar 2014, 14:03
80-90 Mem No: 13372
Location: Wrexham, North Wales

Re: Dash gone crazy

Post by BertieWells »

I forgot to mention,

I looked at the headlight switch and a previous owner has done this ...

Image

The blue/grey wire has been cut and spliced into the grey wire below. Can anyone advise me why this would have been done? Is it part of a known mod or perhaps was this a quick fix for something. Its worth noting that the dash light dimmer dosent work. Could this be the reason why?

Rob
1985 1.9 DG

MidLifeCrisis
Registered user
Posts: 566
Joined: 20 Nov 2011, 19:07
80-90 Mem No: 10519
Location: Bagshot, Surrey

Re: Dash gone crazy

Post by MidLifeCrisis »

BertieWells wrote:I forgot to mention,

The blue/grey wire has been cut and spliced into the grey wire below. Can anyone advise me why this would have been done? Is it part of a known mod or perhaps was this a quick fix for something. Its worth noting that the dash light dimmer dosent work. Could this be the reason why?

Rob
You're spot on - the blue/grey wire is the output from the dash light dimmer - so in the past it would have a variable voltage on it;
It's been connected to the feed that goes to the parking lights - so the dash lights will always be on 'full bright' when the parking lights are on.
Maybe the dimmer packed up and the PO 'hotwired' it to get it going !!

Lovely neat job he's done mind you !!!! :shock: :shock: :shock:
1987 Westfalia Van, Petrol 2.0 AGG

User avatar
BertieWells
Registered user
Posts: 202
Joined: 27 Mar 2014, 14:03
80-90 Mem No: 13372
Location: Wrexham, North Wales

Re: Dash gone crazy

Post by BertieWells »

It's "Art" :D

Awesome, i had the multimeter on it the other day and resistance was changing while i twiddled the nob. Cant remember values but it was doing something. I guess ill have another poke around :)

Cheers

Rob
1985 1.9 DG

User avatar
marlinowner
Registered user
Posts: 1530
Joined: 28 Jan 2014, 12:02
80-90 Mem No: 13646
Location: Scottish Borders

Re: Dash gone crazy

Post by marlinowner »

In defence of the previous owner, maybe this was a quick side of the road no tools repair when the lights failed, which then got left as it carried on working. Not much risk involved as if the wire comes loose it won't have an power on it.
1993 SA VW T25/T3 2.5i Microbus/homebrew camper
1981/1968 Marlin Kitcar TR6 Engine

Post Reply