Trip Computer Stop Lamp Warning Problem

[xr6tjet 98]

I'm having an issue with my trip computer... the "stop lamp" warning comes on when I brake. I've checked the dash loom earth under the left kick panel and its fine, checked the wiring behind the trip computer and it looks like it was tampered with however I wired it back up to original standards (my guess they tried to fix the warning??) green and red wires were stuffed with. I also put a new cable from the battery to the engine earthing point. I have 3 trip computers, all of them do the same thing. The newest one I got didn't display the logo for a while then after a week or so it came back. The rear globe holders don't have any rust either, they look clean. Starting to think it might be the brake light switch on the pedal? Where does that actually earth?? I have two brake light wiring looms from two switches. I think one is for the trailer however I disconnected it and just closed the wires with tape. Really starting to get frustrated now!! Anyone who can shed light on the subject would be greatly appreciated!!

Cheers, Alex.

[Mr Polson 10,214]

Try changing the plugs for the brake switch around, one runs to the cruise control loom the other the the brake switch, swapping then might help.

[GspecZL 979]

My ZL used to do this. Me and my mechanic spent some time trying to find out why it was doing it. Eventually i lived with it. Then my trip computer went completly mad. I replaced and the light doesnt work on the new one!

[xr6tjet 98]

My ZL used to do this. Me and my mechanic spent some time trying to find out why it was doing it. Eventually i lived with it. Then my trip computer went completly mad. I replaced and the light doesnt work on the new one!

So you put another one and it went away? Or is the bulb just removed?? I just find it weird how 3 trip computers can do the same thing. One of them didn't have it for a while then it came back.

 

Try changing the plugs for the brake switch around, one runs to the cruise control loom the other the the brake switch, swapping then might help.

I had a good look at the plug last night, I saw that the previous owner for some reason hooked up one of the green/red wires from the loom to the cruise control red/green one and then just left the original cruise control one hanging from that loom. I wired it back up to original, there are two green/red wires going from the trip computer loom and they are both wired up correctly. The cruise control green/red wire is now hooked up to the actual wire its suppose to be on the cruise control loom.

[PH351 314]

Common problem I guess, my FE does it to but I never fussed myself with it.

[GspecZL 979]

the second computers globe was blown. I was going to pull my globe out anyway.

[xr6tjet 98]

I realise its a common problem but there must be some sort of fix for it? Sounds unlikely to me that a few trip computers can have the same problem. Sounds like something in the actual wiring system?? Does anybody know where the brake light switch earths? I had a good look last night but it looks like its going somewhere up into the dash.

[Mr Polson 10,214]

I would assume it runs into the dash wiring and earths via that...

[xr6tjet 98]

I've checked everything literally and no go lol. Any other ideas?

[Mr Polson 10,214]

Ask an auto sparky?

[xr6tjet 98]

No time for an auto sparky :< full time work ! lol I was hoping i'd work out the issue !

[Nigel 2]

(From my thread on xfalcon)...

So - the Process.

1.   Get Diagnostic Panel out.   No pictures of this part, but to summarise :
    a.   put downward pressure on the panel cover, and pull out at the bottom.   Then unclip the cover from the top.
    b.   Undo the 3 screws holding the panel in.    The Manual says these are torx, however mine were phillips.
    c.   Remove the unit, and unplug the connector.
1a.  if your going for a quick fix, simply bridge the two Green/Red stripe wires here with a quickcrimp.   The brake light warning will come on when the brakes are on, however the brakes will work.

1b.   Lets do the fix in the unit.


2.   Undo the 5 screws holding the cover panel on and remove the cover panel


3.   Undo the 2 screws holding the Switch frame on and remove the frame


4.   Undo the two screws at the back where the connector is (no pic sorry)

5.   Gently pull the assembly out.  It may be quite tight.  I used a screwdriver to gently lever the PCB stands (black plastic things) at each end.   I also pushed gently at the connector.


6.   The issue is this resistor load pack just above the connector.  mine has a brown mark on it where it has failed.


7.   There are two Large pads there that can be used to bridge the circuit.    

Clean the coating off the pad - I used a knife


8.   Join the Pads.   Ive used some solid 240v power cable here....


9.   Finished product.


9a.   I didnt think to do this, however you should probably remove the brake Fail lamp.
In this picture, its the top left lamp in the cluster of 5.   Just remove the holder


10.   Reassemble the unit.
11.   Reinstall.
12.   Enjoy working brake lights.   Remember to rewire the trailer connector if you have one.

[xr6tjet 98]

I've read that thread however thats if your brake lights arn't working whereas mine are working fine. For now I've taken the bulb out on the second unit I have and just use that for now. Would like to find a fix to the problem though i can't seem to believe its 'unfixable'

[ZL. 19]

As said its a very common problem in ZL/FE usually the bulb holders(in the boot) are poorly earthing, even though they look fine. most likely the heat from the globes warps the plastic just enough to cause an inconsistant connection.

[xr6tjet 98]

As said its a very common problem in ZL/FE usually the bulb holders(in the boot) are poorly earthing, even though they look fine. most likely the heat from the globes warps the plastic just enough to cause an inconsistant connection.

 

I inspected the globe holders multiple times but my ones have an earth wire exiting the holder (looks factory) and it joins somewhere in the tail lamp loom. I'm not actually sure where that earth leads. Any more light on the subject would be good. Photos even of what to look for? I can take a photo tonight of what I have in my car.

[Mr Polson 10,214]

Did you have any luck with this?

My wagon does it (brings on the stop lamps warning light). All (both) brake lights are working.

 

I too would quite like to fix it if possible...

[xr6tjet 98]

I tried a million things in the end I had one trip computer that would not reset the time (I have been driving the car for 4 months now without the time being reset) so I ended up removing the bulb in that trip comp. I have collected around 4 trip computers now and they all seem to have their own little issues. My understanding is that the resistor pack in the back of the trip comp seems to stuff up and in the end I just left it at that and focused on more important things. 80s electronics! I would like one day to have it fixed though its a handy feature. Would hope someone out there can recondition these vdo trip computers!

[GspecZL 979]

Yeah surely someone could recondition them? There is a guy at work who fixes all the monitors, B P machines, pumps and other equipment in the hospital. I think il ask if it would be hard to source the stuff.

 

Mine after 12 reliable months lost 2 hours the other day. Very sad day.

[Mr Polson 10,214]

You'd think so...

Mind you, Ford did only put the date in them up to 1999, they're 14 years past the end of their own time

 

I have been thinking for some time now, its the resistor that tends to fail and brings the light on right?

 

If so - would this idea be possible (I have no idea about electrics like this so it may be a rather stupid idea I dunno...)?

 

Would it be possible to get a resistor of some sort and wire it into the circuit? I may be wrong, but from what I can tell, the circuit works similar to the way an indicator flashes fast when blown? The lack of resistance causes the light to flash faster - also happens if the wrong wattage bulb is installed.

The xf trip comp must be similar, when brake light blows, resistance is lower and brings on the light.

[GspecZL 979]

Meh way over my head Chris. If it wasnt so cool i would just go get an XF clock. The DTE thing its crap anyway. I fill up and it says 680km and then at half a tank it says 12km. Ive got a good one now but jeez there annoying at times. The other features are fairly useless.

 

I think its funny they dont go past 1999. Ford was Y2K concious i see lol

[Mr Polson 10,214]

My DTE is accurate says about 680km when full to the brim - discovered wagons have more than 70L tanks the other day when.mine took 80L. Was almost out of fuel though. Comp said 23km to empty... I've never had it that low before.

 

I like the other features... fuel economy is nice to watch, fuel used is handy (in case the dte was to be wrong). Having three trip meters can be good sometimes. Time I don't worry about though.

 

On topic of brake light thing, could it be tied to number of brake lights in the vehicle? I noticed Panko's Ghia has a high mounted brake light

 

 

But mine doesn't?

 

 

Once again, more/less resistance theory would come into play.

[GspecZL 979]

well the ZL does it but all my lights work and are present. As i said i just took out the globe.

 

80L tank is handy. What does the Fairmont Ghia sedan have? I wondered if my trip computer was from a monty with a smaller tank and thats why it beeped sometimes.

[Mr Polson 10,214]

60 something L or optional 80/90L long range tank?

 

Brads Ghia has the long range one, but I don't think he's fully filled it... he stopped once it took $120 worth.

[GspecZL 979]

haha yeah its a mother to fill. When the first light goes off (for the 11th time) on the fuel guage its a sad moment. Nothing llike knowing you have alllllll that fuel back there when its full.

[Mr Polson 10,214]

Wagons are a bugger to fill... think its the design of the filler neck. Pump goes click, but if you go drive away you only have 3/4 a tank. Gotta spend 5 minutes slowly squeezing the trigger, waiting for fuel to go in, squeeze trigger...

 

Even doing that the first bar goes down quick. Last bars seem to be longer.

 

Ute is the other way around. You can do 200km on first bar. But once you get to half a tank you've gotmore like 1/4 or 3/8s.

 

Hmm. Utes trip comp doesn't bring up stop lamp light. Might test it in wagon.