Series IIA Ignition Cut out?

[109sixer]

Been having a electrical Gremlin here. Replaced coil, dist, points/cond
etc...also checked fuel pump, carb, plugs. Replaced ignition switch and wiring.

The problem is strange...the ignition will just cut out...if I flip the
switch it will start up again..run for a while and cut out randomly.
I know it sounds like a short somewhere. I have been putting off
replacing the entire wiring harness for a while. I'm hoping there is
a easy fix here that someone may have run into before?:(

[B. Wallace]

I'm sure there's a thousand different possibilities, but I had a similar problem a while back. Mine's a SIII, but I discovered tha when I tapped the bottom of the steering column, where my fuse box is located, I could cause it to do the same thing. What I figured out was that one of the prongs that the fuse sits in was a little loose, and would cause the ignition to cut on and off while driving. I simply took the fuse out and crimped the prongs tighter with a needlenose plier.
It's sometimes the really simple things that can cause a major problem. Don't feel dumb if it is something like that, we've all been there and it took me a while to find my gremlin:D

[J!m]

Have you inspected the ignition switch itself (where the key goes in)? With age, these parts wear, and you could have an intermittent connection here. Turning the switch makes the connection, and then a bump comes along and rattles it loose on you...

Maybe check this before the harness ends up in the land fill.

[109sixer]

I've been told that SIIAs truck does'nt not have a fuse in the iginition circuit...
but I will check to see if someone has done some "custom wiring". Thanks
for the reply!

[109sixer]

Jim,

I have replaced the switch...the switch that was in there was a Kragen
special, so of course That was the first thing I threw out. The harness
is 37 years old and getting crunchy. I've heard of a place in Portland
that sells replacement harnesses for less than 200 bucks. It's called
the Hoffman Group. I'm thinking of ordering one of those for prevenative
maintenance. It would really suck to replace the harness and have the
problem not go away.

http://www.thehoffmangroup.com/KeepItClean/Products/Products_KICK.lasso

[Tim Smith]

Where is your ignition switch? Dashboard or the steering column?

If it's in the dash, then I would check the connections in the back. There is a lot of room for things to get pushed around back there though the years. You know, someone fixes a dash bulb but crammed all the wires back in there when reassembling the dash, causing too much stress on a connector for the ignition. Then one good bump, 10 years later and it comes loose and now you have a gremlin.

[Tim Smith]

Oh, just thought of a test you can do to check the ignition switch (and possibly remove the coil, dist, wires etc from the equation).

Turn on your heater blower on, or something else that works only when the ignition switch is on, and wait for the issue to show up again. When the engine fails then you will know it's the ignition switch if the blower fails too. If it doesn't then it might not be the switch but could be the wires further down the line.

Good luck!

[109sixer]

Tried the heater switch trick...the engine cuts out but the fan keeps going.
It seems to get worse when it has been running for a while ( Hot ).

By the way the power to the heater switch comes from the coil? This thing
is a mess!

[daveb]

not all heaters are wired to the ignition side. not a surefire test.


Tried the heater switch trick...the engine cuts out but the fan keeps going.
It seems to get worse when it has been running for a while ( Hot ).

By the way the power to the heater switch comes from the coil? This thing
is a mess!

[Tim Smith]

not all heaters are wired to the ignition side. not a surefire test.
True, true. Was hoping for something easy and forgot about that.:o

[109sixer]

OK...the heater is a Smiths flat heater ( Nice, works great ). The problem
began before the heater was installed. I've been behind the instrument
cluster more times than I'd like to admit. I believe the problem lies
somewhere in the power lead going from the harness to the coil +.

I've taken the Dist apart and re-soldered all the connections to make sure
there was no short inside the Dist. then I replaced the Low tension lead back to the coil etc...

My truck is a 1970 SIIA 109 NADA with Euro spec six cyl motor. It has
a Zenith Stromberg carb and the engine is out of a 78 with the smog
stuff taken off and capped.

Just more info to add to the soup!

[Tim Smith]

Tried the heater switch trick...the engine cuts out but the fan keeps going.
It seems to get worse when it has been running for a while ( Hot ).

By the way the power to the heater switch comes from the coil? This thing
is a mess!
So doesn't that mean that your coil is still getting power -> which means that your ignition switch is working?

I'm grabbing at straws. It's kind of tough to come up with a sure fire test without actually leaning under the hood. Although I'm sure the next poster will be able to do it.
:o

[BackInA88]

I've had problems like this before on other vehicles.
I have in the past run a wire right from the battery to the coil to nail down which side of the circuit (engine or harness) the problem is on.

Question, I don't remember, is there a ballast resistor in the coil circuit?
These can tend to get flakey after the warm up when they are going bad.

[singingcamel]

next time you drive it and it cuts out ,check your coil. you may have a bad coil. heats up and then dies .i've seen this problem a few time.also check your coil wire and connections on your coil...
also agree with Mr. Smith on the connections on the back of your switch if its in the dash.
also when it cuts out ,move or wiggle the ignition switch to see if it helps
www.singingcamel.com (http://www.singingcamel.com)

[109sixer]

I've tried both types of coils ... external and internal resistor.
I currently have a brand new Lucas gold coil with a built in resistor.
It's putting out 12 on the battery side and roughly 7 to the distributor.

I'm thinking it must be a fried ground wire in the harness. SIIa's
Have no fuses in the ignition so I could have very well burned out
a wire without knowing. Like they say..."the Smoke will come".

[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.