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Post by jeff on Jan 16, 2021 13:44:27 GMT
So, in an attempt to sort out some of the electrical gremlins on this car, I thought it a good idea to replace the dash mounted ignition switch as mentioned in my post about heater blower mystery. Simple enough you would think right?
A quick look at the WM to familiarise myself with what to expect, and I'm in.
I removed the locking ring and carefully eased the switch from the dash, being careful not to disturb anything.
Theres not much room under there to fiddle about but as soon as I moved the switch to look at the terminals, horror set in as wires started pinging off the spade connectors.
The WM shows 4 white wires leading off to various circuits. Ignition light, indicators, heater and an unfused circuit to ignition coil and fuelpump.
Also, an unswitched side for battery, clock etc. Simple enough you would think. But no.
I found 8 old cracked white wires, with numerous pic-a-back spade terminals, horrible blue crimps, doubled up wires into one crimp etc etc. Talk about overload! The whole lot just came apart in my hands, honest guv!
So now I've got the delightful task of trying to work out what goes where and try to make it safe. It's only a 12 volt circuit but a lot of amps and as it stands a potential fire hazard.
I have to say I hate those blue crimps. They look ugly and never seem to hold well especially if the wires are doubled up or are crimped without the proper tool.
I dare say the proper Lucar type connectors with soft insulating sleeves are hard to find now.
Well, all the moaning and whinging in the world wont fix it so I'd better pluck up courage and rip it out and start again. God knows where all those white wires go. There seems too many and they disappear into the loom.
What a mess trying to sort out previous incompetent botches.
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Post by tonymark3 on Jan 16, 2021 16:30:54 GMT
I suspect it’s time to purchase some white wire,solder and heat shrink! I must confess that back in the seventies I used those 3M connectors for my tow bar. All done properly now. I see what you mean about all the white wires! I suppose you could apply a voltage to them one at a time and see what works if you feel brave.
Tony S
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Post by Penguin45 on Jan 16, 2021 18:15:52 GMT
Oh dear. Time to face up to pulling the dash? Might as well get all the horrors out of the way in one go.
Chris.
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Post by jeff on Jan 16, 2021 19:14:08 GMT
Well I've made a start and ordered a kit with a load of connectors and a proper crimping tool, even tho it contains some 3m type blue connectors. Done properly I suppose they should be ok.
Has anyone bought automotive wire? I'm getting confused as to awg and swg , thin wall etc etc.
A supplier who will sell a bundle of various lengths and gauges.
I found one, auto electrical supplies, will do braided cable, in a bundle of colours and sizes.
But at a price.
Any ideas?
Once I've got it running again temporarily,so I can work with the door open the shelf has to come out at least to get reasonable access. Then I can get into the rats nest.
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Post by jeff on Jan 16, 2021 20:41:23 GMT
Has anyone got a picture of the AMP fuse/connector plate,  particularly the back. I've never had one off and would like to see what it's like before I pull any connector blocks off |
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Post by dave1800 on Jan 17, 2021 5:42:22 GMT
Sounds like a lot of fun - not! Lucas had their own system for wiring harnesses. If you want to stick to the original set up and not design something more logical I can offer the following advice. Try and keep to the original wire colours as per the w/s manual. If not possible keep a record of what you do for future reference. I would strongly advise against using the 3M type connectors as they can sometimes damage the wires they splice potentially leading to overheating and reduced power capability or failure. A properly crimped spade connector is the best solution but a combination of solder and crimping would be fine. Ensure the spade connector is a tight fit and all the contacts thoroughly cleaned. Thin wall automotive wire is suitable as long as the current rating is at least twice that of the relevant fuse. It is easier to bend especially in confined spaces. UK uses SWG, the US AWG. There are charts on the web showing the conversion eg AWG / SWG and current rating. This is a job you probably only want to do once, so take time to ensure all the connections are good and the wires won't vibrate! David |
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Post by tonymark3 on Jan 17, 2021 13:47:56 GMT
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Post by tonymark3 on Jan 17, 2021 13:56:37 GMT
Oh sorry, didn’t read yours properly, see you already have been to auto electrics. I used the standard pvc cable on mine, thin wall is for the modern cars .
I did all my additional connections with soldered bullets and connectors. Quite handy as if you need additional take offs for power or earths you can use multi way connectors.
Tony S
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Post by jeff on Jan 17, 2021 16:11:38 GMT
Afternoon guys, and thanks for all the above.
Nice day today. I really should have gone onto my farm,... well, allotment... well..
half an allotment... to pick Brussells sprouts, but the landcrab wiring kept me awake last night, so I thought it best not to go out as I'm Covid shielding. So Mrs Jeff went essential shopping instead.
I lay in bed 4AM, wide awake thinking of a logical sequence to find a place for all those old wires that had pinged out of the ignition switch terminals. As it turned out I figured if I found a wire with 12volts, that would be a start. Then touch each wire in turn to that live 12v until I found the starter solenoid feed. Yep! So now I can locate the correct terminals on the switch.
Batt=number 3
Solenoid = number 1
Ign, fuel pump, oil pressure, and ign warning light =number 2.
I found a spare white wire which I figured feeds the blocked filter warning light.That was cut off at the oil filter by the PO, apparently they are troublesome??
The only bits I wasnt too happy about were, the green wires supplying heater, and brakelights,which are rightly connected to the battery side of the voltage stabilizer,but fed from the spare lug on the number 2 terminal of the ignition switch. That "should" I think go to the fused A4 terminal in fuse box.
Anyhoo, I managed to cut back and recrimp spade terminals nice and tight. It's a temporary fix for now until I get to cut right back and re wire and re terminate with new wire using the kit I just got from Amazon, same as in the above pic from machine smart.
Well now, some good has come from this. I now know what feeds what, and what apparently shouldn't according to the WM..
The car starts first lick from stone cold, no wavering tacho, and no faltering revs on tick over and everything working including brake lights, wipers etc.(Even the wipers were struggling before).
With everything switched on theres no sign of smoking wires or the ignition switch getting warm.
In conclusion It would appear the ignition switch was the culprit coupled with bad connections.
When I get to rewire that lot properly I have a sneaking suspicion I will uncover some random loop which is contributing to the delayed engine kill with the heater blower running. But, that's another story for another post.
Next stop, next spend, Auto Electrical supplies.
Jeff.🙂
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Post by 1800heap on Jan 17, 2021 23:01:26 GMT
Hi Jeff Hopefully these help a bit, although they are pictures of my MK3. The trick on my car to get some slack, was to unclip the loom inside the car from the firewall. It was tucked under the carpet. Pull all the plugs from the engine bay first. The connectors are not insulated so disconnecting the battery is wise!    The result of a bad connection!  The bare spade connectors for the plug and socket arrangement are available form Jaycar. They are a good fit with a very minor mod to the holding clip on the spade. If you need to replace any let me know and I will give you some more detail. I have added some extra wiring through the plugs on mine using them. I think the pictures might be before I did this. Nick Has anyone got a picture of the AMP fuse/connector plate, particularly the back. I've never had one off and would like to see what it's like before I pull any connector blocks off |
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Post by jeff on Jan 18, 2021 11:00:24 GMT
Thanks for those pics. Pulling that lot apart is not for the faint hearted I'm sure.
Looks like some bad connections and heating there.
Reminds me of when I worked for BT opening cable joints and junction boxes..
I wonder how many of those plugs got misfitted on the assembly line? I bet they can be a nightmare to line up and refit once disturbed.
Think I'll leave well alone unless I really have to pull the board out.
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Post by Penguin45 on Jan 18, 2021 13:54:39 GMT
Once the dashboard is out of the way, the plugs can be pulled out of the front of the fusebox. Undo six screws and with a slight twist and roll, it can be fed back inside the car where it's nice and easy to work on. Be gentle though, they're quite brittle these days and hard to find to replace.
Chris.
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Post by jeff on Jan 18, 2021 19:31:47 GMT
Yes chris I can imagine. I've looked all over the web but cant find a trace of them.
I wonder why they went over to AMP? I'm surprised Lucas didnt come up with a solution if BMC wanted to go for ease of assembly using plugs and sockets.
I dont recall ever seeing them on other cars. Even the Maxi didnt have them, nor did the princess. Seems strange that only ADO 17 used that system. An experiment perhaps???
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Post by dave1800 on Jan 19, 2021 11:32:52 GMT
Well done Jeff! I wonder how many dodgy ignition switches and connectors there are out there. Do you plan trying to take the switch apart to identify the problem? It certainly illustrates the value of carrying out voltage drops on the ignition coil feed as any loss can make starting difficult and maybe run poorly. Likewise slow wipers and flashers can result from the same cause. To test the ignition, for example if you have points, turn on the ignition with the points closed and measure the voltage from the ignition coil supply terminal to the battery negative for positive earth (battery positive for negative earth)- it should be no more than around 0.5volts. David ......... Batt=number 3 Solenoid = number 1 Ign, fuel pump, oil pressure, and ign warning light =number 2. I found a spare white wire which I figured feeds the blocked filter warning light.That was cut off at the oil filter by the PO, apparently they are troublesome?? The only bits I wasnt too happy about were, the green wires supplying heater, and brakelights,which are rightly connected to the battery side of the voltage stabilizer,but fed from the spare lug on the number 2 terminal of the ignition switch. That "should" I think go to the fused A4 terminal in fuse box. Anyhoo, I managed to cut back and recrimp spade terminals nice and tight. It's a temporary fix for now until I get to cut right back and re wire and re terminate with new wire using the kit I just got from Amazon, same as in the above pic from machine smart. Well now, some good has come from this. I now know what feeds what, and what apparently shouldn't according to the WM.. The car starts first lick from stone cold, no wavering tacho, and no faltering revs on tick over and everything working including brake lights, wipers etc.(Even the wipers were struggling before). With everything switched on theres no sign of smoking wires or the ignition switch getting warm. In conclusion It would appear the ignition switch was the culprit coupled with bad connections. When I get to rewire that lot properly I have a sneaking suspicion I will uncover some random loop which is contributing to the delayed engine kill with the heater blower running. But, that's another story for another post. Next stop, next spend, Auto Electrical supplies. Jeff.🙂 |
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Post by jeff on Jan 19, 2021 17:13:44 GMT
I would have expected a bit of voltage drop maybe more than 0.5v
Due to warning lights, gauges, and possibly fuel pump depending on where it is on its stroke.
Anyhoo, for the avoidance of doubt, I pulled the A4 fuse and everything that should be protected by that fuse stayed off, so something is right somewhere..
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particularly the back. I've never had one off and would like to see what it's like before I pull any connector blocks off
