Series IIA Ignition Cut out?

[109sixer]

I've checked behind the dash and replaced the wires any suspect wires.
My next step is going to be to split the harness open and trace the wires
all the way to the battery. OR I could just replace the harness completely
since it's probably less work.

[Erin]

Have you tried hot wiring your truck? Give it a try. Your truck is easy to start. If your points, valves, plug gaps, and timing are set then your fault should be found in a loose connecion, likely in your ignition switch. Tighten it up, step by step. They're not that difficult, regardless of the Lucas haters. If your distrubuter is properly wired you will have little issue.
Best of Luck,
Erin

[109sixer]

Have you tried hot wiring your truck? Give it a try. Your truck is easy to start. If your points, valves, plug gaps, and timing are set then your fault should be found in a loose connecion, likely in your ignition switch. Tighten it up, step by step. They're not that difficult, regardless of the Lucas haters. If your distrubuter is properly wired you will have little issue.
Best of Luck,
Erin

Thanks Erin,
I will trace all the wiring from the switch back and see where the short is.
I already replaced all of the wiring in the Lucas 25d.
This is the strangest issue I've seen in a while. My friends who have similar
vintage trucks and motors have never had any issues. I guess when the
harness gets old, the casings can erode to the point where enough heat
can create less than ideal insulation causing shorting. Specialy along the
firewall behind the back of the head where the oil seems to seep.

Do you know of a an upgrade solution for the IIA wiring? I've heard
suggestion to use a SIII harness since it is fused. Others have recommended upgrading to aftermarket off the shelf harness that
come pre-wired with a fuse boxe.

I would love to hear about anyone who has done a new harness with
an alternator upgrade at the same time.

cheers and thanks for all of the replies!

[jp-]

I've installed two new harnesses to date. The first on the NADA and the second on the 88". Both were done in the course of restorations. I bought my harnesses from Paddock's in the UK, with special instruction to wire for alternator. The quality seems very good. The only issue was a few wires that were too long (none were too short) and the extra wire had to be tied off. No big deal. I will tell you that the wiring harnesses for the NADA are more complicated (only slightly so) than many others. So just be clear when ordering.

Installation -

When you first get the harness, you will think, 'my god can I actually hook this damn thing up?' The answer is yes, but be prepared for many hours of work. Time was never an issue with me, because I just hooked up the wires as the restoration progressed. One hard thing to do (nearly impossible without the body off) will be to run the rear half of the harness through the frame. The harness came in 4 parts (at least mine did); the main engine harness, the rear harness, the alternator harness, and the dimmer switch harness. The good news is that you can just install the engine harness if you want. The bad news is that you will at some point have to replace the rear harness, and if you have wiring for an alternator, you'll need to have the alternator setup ready when you go in with the new engine harness.

It does not come with a fuse box, but is prewired for the original fuse box. I believe you can upgrade this if you want.

**Oh yeah, don't forget you're going to need a lot of new bullet connectors and ground clips (maybe a few extra bullets too, for any accessories you may have). I ordered these from Triple-C, look them up.

[jp-]

As to your original problem, anything can be fixed. Can it be fixed at a later date (without installing a new harness now), absolutely it can. So if you plan to do a restoration at some point, you may as well wait on the harness. However, it is your call, and there is no way to tell just how bad it is without actually seeing it.

The problem is without doubt a loose (or corroded) connection/ignition switch internal connection.
Singing Camel is correct that the coil can at times be at fault for engine cut out, however (in my experience) when the coil overheats the truck may be down 10 minutes until the coil cools back down. Momentary engine cut out, with an almost immediate return to normal running can almost always be attributed to faulty wiring/ignition switch failure. (It is important to note, that momentary engine cut out, with a *delay* in the return to normal running can also be attributed to fuel delivery problems.)

Now that the problem is identified, all you have to do is fix it. With the engine running there must be good connections at the ignition switch (both incoming power and outgoing power to coil), ignition coil, distributor, and engine ground.

1. Make sure that the engine grounding wire (to the frame) is solid and is good and clean where the connections are made.
2. Check the ignition switch hot lead that comes in from the battery (solenoid). Do you have a good connection at both ends?
3. Check the connection from the ignition switch to the coil. Is it loose on either end?
4. Check the wire from the coil to the distributor.

Start the truck in nuetral (with the gauge panel off, be careful not to let any of the wires short) and start wiggling wires. If nothing fails to duplicate the cutout problem, go under the hood. Move the coil wires, move the hot leads going into the gauge panel.

9 times out of 10, expect the ignition switch.

[Jim-ME]

FWIW I had an issue with my origional Rover where the ignition would cut out because I has too many keys on the key ring I was using, When you hit a bump the keys would swing from side to side shutting off the ignition. Have you tried using a single ignition key and see if it still does it?
Jim

[greenmeanie]

I had an intermittent ignition cutout recently on my '71 IIA. It turned out to be the way the heater control cable was routed around the coil. Over time the cable moved and ended up shorting out the low tension terminal of the coil. After standing at the side of the road with a bit of head scratching and a mild electric shock I figured it out. It was nice that the fix was really easy but I did feel like a bit of an idiot at the time. The heater cable is now sleeved in that area.

Sometimes the answer is simple and, while I agree with the others that the most likely culprit is the ignition switch, it also pays to look at what is around your coil connections for anything that they could short to and alsp have a good look for areas that the leads could be rubbing.

Cheers
Gregor

[109sixer]

Yeah, I suspected that so I dorve around with the heater control cable unplugged and sure enough the problem was still there. I even replaced
the connections etc...I'm starting to suspect an stckiy valve at this point.
It never hurts to do a valve adjustment anyway.

thanks for the response.