Electrical faullt

[coachman]

Coming home yesterday in my 1500hl I stopped at a friends house everything was working in the car as normal. When I left the fuel, water temp; and rev counter had stopped working and the overdrive would not engage. This morning I went out and started the car up and everything was working as normal, has anyone any thoughts as to why. Your help would be gratefully received. Thanks in advance.

[MIG Wielder]

My first thoughts would be a problem with the IGN ON fuse.This is the one with the white cables on one side and the green cables on the other. You would have probably found that the brake lights, the heated rear window and the wipers, the reversing lights, and the indicators were all dead as well. The first thing I would do is pull the fuse out and clean the contacts. Then check the condition of the green cables and the connection at the fuse box. Then inspect the fuse itself carefully. The ends can become unsoldered if they get hot. Best replaced.
HTH,
Tony.

[coachman]

Thanks for your input I will take a look tomorrow.

[veeeight]

I have exactly the same problem as you. All the ignition connected items go off together, but not all the time, only sometimes.
I am working my way through the ignition wiring, starting at the fuse box connections etc. I am also considering cleaning the loom connectors by the steering column with a electrical cleaning spray. The strange thing is that the car still runs and drives when the ignition circuits go off, even though my coil supply is connected to the ignition feed.
Let me know how you get on. Phil

[Carledo]

I have exactly the same problem as you. All the ignition connected items go off together, but not all the time, only sometimes.
I am working my way through the ignition wiring, starting at the fuse box connections etc. I am also considering cleaning the loom connectors by the steering column with a electrical cleaning spray. The strange thing is that the car still runs and drives when the ignition circuits go off, even though my coil supply is connected to the ignition feed.
Let me know how you get on. Phil

The coil circuit has a different lead from the ignition switch to the one that feeds the fuse box, or sometimes, depending on year, the coil feed is an "in-and-out" at the white terminal on the fusebox. Either way, if it keeps running but loses ignition controlled circuits, the problem is at the fusebox, not the ignition switch and probably not at the under column block connector. If you have drawn a (EI?) feed from the white wire side of the fusebox (unfused side) then power is getting to that point, so your problem surely lies in the fuse itself or the fuse connections to the fusebox.

[veeeight]

I have a Elec Ign feed from the non fused side of the fuse box but there is also a feed there to the voltmeter which also stops working when the ign
circuits fail. So a bit confused why?
I have cleaned up all the connectors and the fuse holder, so will see if that solves the problem.
Otherwise, all that you say Steve is spot on.



The coil circuit has a different lead from the ignition switch to the one that feeds the fuse box, or sometimes, depending on year, the coil feed is an "in-and-out" at the white terminal on the fusebox. Either way, if it keeps running but loses ignition controlled circuits, the problem is at the fusebox, not the ignition switch and probably not at the under column block connector. If you have drawn a (EI?) feed from the white wire side of the fusebox (unfused side) then power is getting to that point, so your problem surely lies in the fuse itself or the fuse connections to the fusebox.
[/quote]

[Richard the old one]

The loss of the voltmeter read may just be that the earth connection to the voltmeter is not very good. I suggest you check that the actual voltmeter connections are making a good contact. I did have a problem and It took me quite a time to find it was actual the voltmeter negative connection. Check spade connection to screw tread.

[Richard the old one]

Have you also checked the fuse electrically. You need to do it with a meter as I had one that looked to be ok but it was no longer passing any current.
I will also include the 1550 dolomite ignition circuit diagram which I included in Dolly Mixtures no so long ago

[Carledo]

I have a Elec Ign feed from the non fused side of the fuse box but there is also a feed there to the voltmeter which also stops working when the ign
circuits fail. So a bit confused why?
I have cleaned up all the connectors and the fuse holder, so will see if that solves the problem.
Otherwise, all that you say Steve is spot on.

That lead that powers the voltmeter also supplies the tachometer. If that's still working then the voltmeter fault is probably the earth as Richard suggests.Since the earths all loop around everything behind the dash, it's concievable the VM is getting a partial earth from somewhere else when the fuse is working that drops out when it's not. This IS 40 year old Lucas wiring we're discussing here!

Steve

[veeeight]

I have a Elec Ign feed from the non fused side of the fuse box but there is also a feed there to the voltmeter which also stops working when the ign
circuits fail. So a bit confused why?
I have cleaned up all the connectors and the fuse holder, so will see if that solves the problem.
Otherwise, all that you say Steve is spot on.

That lead that powers the voltmeter also supplies the tachometer. If that's still working then the voltmeter fault is probably the earth as Richard suggests.Since the earths all loop around everything behind the dash, it's concievable the VM is getting a partial earth from somewhere else when the fuse is working that drops out when it's not. This IS 40 year old Lucas wiring we're discussing here!

Steve

The tacho also goes off when the ign circuits fail. Looking at my wiring diagram the tacho 12v is supplied from the fused side of the fuse box, not the non fused side. Everything works ok when the ign circuits re-connect themselves after going off for a few minutes, just like magic.
If it carries on, I might fit another fuse and holder across the fuse clips and see if that stops the circuits failing. I also have a spare fuse box I can try.
Thanks all for you help and suggestions.

Phil