XF electrical issue - cluster

[XFChris 126]

I put a ZL digi cluster into my XF GL months ago.

 

This past sunday I had just left home and got a minute down the road when I noticed the cluster gauges display turn off, then the battery light came on dimly, thought nothing too big of it then carried on.  About half a minute later smoke was starting to pour out from behind the cluster, so I pulled over immediately and switched the car off. 

 

I checked under the dash for any obvious wiring shorts/damage, nothing obvious there, so I then checked under the hood, I noticed the negative terminal was not tightly on the neg battery post. Took, it offTightened that up, then turned the car on.

 

Everything seemed ok, but the radio and the trip meter did not reset themselves, as they should when you disconnect the negative off the battery. 

 

I thought that with the battery now connected good, that was the end of it, got a few minutes down the road, then I notice the cluster display dimming and the battery light come on, pulled into a carpark and topped up the battery water.

 

On the move again, then I am hit with another wave of smoky cluster, I pull over, then I decide to unplug the cluster then try to make it back home. With the cluster unplugged, I got home with no dramas.

 

I have since put the GL cluster back in the car, but I still have an issue where the cluster will lose power, and the battery light will come on. Also, at times, the speedo needle will go up up past 40-50kmh, even though the car is stationary in neutral.

 

So I can rule out the cluster being the problem, has to be with the car itself, any ideas where to start looking?

[SLO247 1,713]

For a start check the inst fuse is the right one.

 

I had a dodgy trailer keep blowing that fuse in mine. Caused the cluster to turn off and lost the alternator charge too.

 

Sounds like you are having something wrong on that circuit but for some reason its not killing the fuse first.

[Outback Jack 6,352]

If you had smoke, you burnt something out and/or have a short. Check ya wiring harness hasn't got hot and melted a few wires together.

Best of luck.

 

Jack.

[gerg 10,871]

Neg terminal off while running = fried alternator. The diodes blow out because the reg has no reference to earth, so the alt punches out whatever volts it's capable of (say 18 volts) and fries other stuff along the line, like maybe the voltage reg in your cluster or the alt lamp diode in the dash (hence the dim alt lamp when running). Check batt volts both with engine stopped and running. Switched off should be 12-13 volts, running should be 13-14 (maybe give it a little rev to bring volts up). This will tell you if your alt is good or not.

[XFChris 126]

I'll check the alternator this arvo.

Then I'll try find where the dash loom connects to the engine loom, and check with a multimeter and test lamp. There is probably a short in the speedo signal wire, since it jumps up randomly

[XFChris 126]

If I can't figure it out by Sunday, I'll send the car to an auto electrician next week

[gerg 10,871]

Speedo jumping might be cluster voltage regulator

[XFChris 126]

You can never look too many times... There is wiring that has had the insulation melt... Perhaps all that smoke was the insulation melting, it did have a very unpleasant smell, and people say burning plastic is a nasty smell.

 

Inst fuse seems fine, and it's the recommended 20A. Alternator seems to be ok as well.  12.29V at battery off, 13.89V running

 

I think I will chop out and replace the fried wiring, and see how I go.