ACC Ignition Key Position Issue

[samkost]

After reassembling my dash components, for some reason the left key accessory position on the ignition switch has decided to not power on.
What steps should I take to diagnose?

Could the culprit be the junky aftermarket ignition lock set and or the switch the restoration shop from Hell installed?

Might be time to order an OE set locks from LockDoc!

[Sheepdip]

Originally Posted by samkost

might be time to order an oe set locks from lockdoc!

^^^^^^^^^^^^^^^this^^^^^^^^^^^^^^^^^^^^

[toolboxchev]

1. You could have a short to ground in that circuit and the switch will have little to do with it.

2. Grit, left over from restoration.

3. If its a new switch get a warranty replacement on it. If the heater circuit is or has been working on high they have a tendency to burn up wiring. (not supposed to be this way.) Ask me how I know

Check all your wiring for burn marks or hot spots.

[samkost]

Originally Posted by toolboxchev

1. You could have a short to ground in that circuit and the switch will have little to do with it.

2. Grit, left over from restoration.

3. If its a new switch get a warranty replacement on it. If the heater circuit is or has been working on high they have a tendency to burn up wiring. (not supposed to be this way.) Ask me how I know

Check all your wiring for burn marks or hot spots.

I will tinker with a little checking/cleaning of the lock cylinder and wiring at the ignition switch.
I just buttoned up the new stereo, lights, wipers,heater fan and all the dash cluster functions. Everything works!
It just seems odd that I have no accessory power with the key.

I read that 1967 to early 68's C10's didn't have an accessory circuit at the key ignition? Unsure?
I wonder if I have the wrong ignition switch?
Thanks

[HO455]

Samkost is correct 1967 harnesses don't have wiring configured for the ACC switch position to work. A newer style switch with ACC will plug right in and work. In fact most parts catalogs only list one switch for 67-72 even though the 67 switch is different.

[LockDoc]

Originally Posted by samkost

I will tinker with a little checking/cleaning of the lock cylinder and wiring at the ignition switch.
I just buttoned up the new stereo, lights, wipers,heater fan and all the dash cluster functions. Everything works!
It just seems odd that I have no accessory power with the key.

I read that 1967 to early 68's C10's didn't have an accessory circuit at the key ignition? Unsure?
I wonder if I have the wrong ignition switch?
Thanks

Are you saying that the switch won't turn to the left far enough to activate the accessories or that it turns far enough but there is no power to the accessories in that position? What year is your truck?


LockDoc

[samkost]

Originally Posted by HO455

Samkost is correct 1967 harnesses don't have wiring configured for the ACC switch position to work. A newer style switch with ACC will plug right in and work. In fact most parts catalogs only list one switch for 67-72 even though the 67 switch is different.

Well the under dash wiring harness is the original and the old accessories ignition position was working before it went to the shop.
I also assumed the ignition parts were identical for all six years.
The only thing that changed was the ignition and door set locks (keyed the same) were installed.

Would an bad aftermarket ignition key plug and or faulty ignition switch cause this issue of no ACC power?
I need to get the multi tester out and start the process of elimination.
Thanks HO455

[samkost]

Originally Posted by LockDoc

Are you saying that the switch won't turn to the left far enough to activate the accessories or that it turns far enough but there is no power to the accessories in that position? What year is your truck?


LockDoc

Hi Leon,
The Key turns and clicks to left just fine just no accessory power.
Truck is a 1972.
Where should I start?
Thanks

[Boog]

Check all fuses.

[samkost]

Fuses checked and good.

[LockDoc]

Originally Posted by samkost

Hi Leon,
The Key turns and clicks to left just fine just no accessory power.
Truck is a 1972.
Where should I start?
Thanks

I guess you will have to start with the tester. If it was a switch with no ACC position the key would not even turn to the ACC.

The ignition cylinder itself would not have anything to do with it.

LockDoc

[samkost]

Sounds good Leon,
I will remove the ignition switch and check/test trace the wire leads and connections.
Does the ignition cylinder need any lubrication or dielectric grease?
Thanks again
Sam

[LockDoc]

Originally Posted by samkost

Sounds good Leon,
I will remove the ignition switch and check/test trace the wire leads and connections.
Does the ignition cylinder need any lubrication or dielectric grease?
Thanks again
Sam

Look at post #2 by VetteVet in this thread:

http://67-72chevytrucks.com/vboard/s...d.php?t=735184

It's about a battery drain but it explains the wiring in detail. Some of the posts below that may have some info you can use also.

LockDoc

[samkost]

Will do Leon!

I’ve will study up on VetteVets thread and will report back.

Thanks for the reply and info.

[toolboxchev]

Originally Posted by samkost

Sounds good Leon,
I will remove the ignition switch and check/test trace the wire leads and connections.
Does the ignition cylinder need any lubrication or dielectric grease?
Thanks again
Sam

No do not use dielectric grease. I had tried that on various connections around my older rusty truck to keep things up and running. Ended up going back through it and removing all traces of it.

Exception was the grounds which have a nut and bolt or sheet metal screw to clamp the connectors to sheet metal or engine block.

Dielectric will break contact in other areas. Other use would be on the spark plug boots only. Not the metal contacts.

The reason I went ahead and used it was due to moisture and water problems. Didnt work.

[samkost]

Thanks Toolboxchev,
I'm going to take apart the switch with pigtail tonight. I'll test check the connections, wiring and terminals.
I've read through numerous forum threads on this and I think it may be a bad dirty connection or possible part failure/damage.
Between LockDoc and your suggestions I should be able to figure this out.
Worse case scenario would be to replace with some AC Delco ignition parts.
The ACC terminals on the switch and pigtail has got me curious if there is a connection issue.
Could also be as simple as a bad ground?
Stay tuned.

Thanks for your guys input.

[HO455]

Originally Posted by samkost

Well the under dash wiring harness is the original and the old accessories ignition position was working before it went to the shop.
I also assumed the ignition parts were identical for all six years.
The only thing that changed was the ignition and door set locks (keyed the same) were installed.

Would an bad aftermarket ignition key plug and or faulty ignition switch cause this issue of no ACC power?
I need to get the multi tester out and start the process of elimination.
Thanks HO455

It looks as if you have things well in hand at this point. My earlier post was to keep you from doing what I did, which was spend 3 hours troubleshooting the problem with my ACC position, on my 67. When all I needed to do was a 1 minute search here.

Here is a photo of the inside of an ignition switch from my own battle with one. I had a different problem, but at times I find photos to be quite valuable. If you're interested i what I did go to post 360 in the link.

https://67-72chevytrucks.com/vboard/...698377&page=15

And lastly if you are looking for something to stop the corrosion of electrical components and connections I recommend Corrosion Block. I've used it for decades on ocean going tugboats with great success. A small bottle will do several trucks.

https://learchem.com/products/corrosion-block.html

Good luck and keep us posted!

[samkost]

Thanks HO455,

Wow, the Working Mans Burbon switch at the ACC and Solenoid terminals did get a little warm!
I haven't experienced any smoke or warm wires yet thank goodness!
We'll see tonight when I open up my switch and pigtail.
I will definitely check for No Continuity-Open Loop.
Great information.
Thanks for the link.
Sam

[toolboxchev]

Suggestions:

1. Get a quality DVOM and learn to use it. Read the Ohms across circuits. I disconnect both ends and even check the wires resistance.

2. GMC Pauls is FLAT OUT AWESOME for these parts. Genuine OEM Stuff, you will have it in a matter of days.

3. Check your large brown wire at the Switch, for me, this is the area that causes the most problems with the heater on high. It tends to cook the heater switch and burn wiring, ignition switch and move through the system.

4. The heater only motors out there come from one place and one place only, Standard Motor Products, they are rebranded for what ever place sells them. They will pull 15 amps or more. It has been the source of my electrical gremlins. Too much demand on the switches and wiring. Why this ends up this way I will never know, at least I have a working heater, and will not use it on the high setting for now.

[samkost]

Success Gentlemen!
Took the ignition switch out to check it and the harness plug.
First observation and I believe the culprit was overspray of hugger orange paint on the switch and wiring.
The restoration shop from Hell left another little surprise for me.

Took everything apart and cleaned with electrical contact spray cleaner.
Brass brushed every terminal, connectors and cleaned the wires.
The AC Delco switch cleaned up nicely.
Buttoned it up and gave it a try.
Accessory left key position powered up.

toolboxchev, LockDoc,HO455, Sheepdip and Boog:
Thanks for your posts, answers and help.
Great guys and a great site.
Time for a victory beverage
Thanks again,
Sam

[toolboxchev]

Glad it turned out Simple!

Double Cheese Time

[LockDoc]

-
Good deal! Glad you overcame this hurdle and thanks for the followup, it will help others down the road.

LockDoc

[samkost]

Thanks, I appreciate all who chimed in.
My old bones are sure glad not to be crawling under that dash anytime soon!
Everything is functioning as it should, I slept well last night.
Thanks again,
Sam

[HO455]

Congratulations!
Barley Pop you say? Why don't mind if I do. Nice truck too!

[MattyBs71]

Let's see a pic of the whole truck? I like it when issues are fixed by simple cleaning and putting back together! My favorite!