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No ignition power to Starter after 4speed MY6 swap

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Dieselmech52

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Hello, long time follower but newbie poster.
Just buttoned up swapping my 700r4 out for a MY6 O/D 4speed in my 86 Blazer. Had a doner 85 K10 that the tranny came out of. Also swapped manual column in. Everything went great until I was done. I can't get it to start! No ignition power to energize starter. I've checked everything I can think of and am ready to install a momentary toggle switch, but would really hate too. Any ideas?
 
Column is out of an 85 K10.
My blazer is an 86.
Ignition stitch on top of the columns were exactly the same between the 2.
Only difference I could see was the auto column has a switch at the base, where it went into the floor, that the backup light pigtail plugs into.
 
Dieselmech52 said:
Column is out of an 85 K10.
My blazer is an 86.
Ignition stitch on top of the columns were exactly the same between the 2.
Only difference I could see was the auto column has a switch at the base, where it went into the floor, that the backup light pigtail plugs into.
Click to expand...


I was checking to see if it was pre-80.. they have a different pin-out to the main column plug.... you need to start isolating the issue...... check your power in to the ign switch at the base of the column, power out, neutral safety, etc... your losing power somewhere out in the signal wire..


do you have all your other power? ign power comes on? power down at the starter? can you turn the key to the "run" position and jumper the starter to start it?
 
Yes, everything else works. I can turn key on and jump start with remote starter switch and it fires right up.
The purple wire at the ignition switch on top the column, which should be my ignition power to the starter, seems to be grounded. I backprobed it with my power probe, and it just blows the breaker on my power probe.
It should be getting 12v when I go to start, but just stays grounded.
Both trucks started fine before the swap.
Only other thing I did was take manual column apart and tighten loose tilt joint before the swap.
 
pull the plug on top of the column and verify you have proper ign power into the column.. than send power thru the signal to verify it's good from the column out.. at that point, it's somewhere in the column...
 
Makes sense. I know I have good 12v at the red wire at the ignition switch.
I was thinking if there is a neutral safety switch in the 700r4 that I pulled, it might be inhibiting it from starting because it's not getting a signal that it's in park or neutral.
Looked in Haynes manual and all-data for wiring schematics, but seems they are so vague, and cover so many years, it's nearly impossible to find your correct application.
 
If it was auto column and you went to non auto column, you will need to attach the two wires that plugged into the neutral safety switch together for it to start. They will be next to the backup light wires at the bottom of the column
 
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Dieselmech52 said:
I was thinking if there is a neutral safety switch in the 700r4 that I pulled, it might be inhibiting it from starting because it's not getting a signal that it's in park or neutral.
Click to expand...

The switch was at the base of the auto column. On the manual trucks GM used the same circuit on a clutch pedal switch. You had to depress the clutch to be able to start it. You should have something unplugged down there...look for it and install a jumper wire to test.
 
That's what I've been thinking the whole time but can't find the wires. What I thought was the neutral safety switch at the base of the column, only has 2 wires that go to the backup lights, no other connection.
No neutral switch on manual column or clutch pedal switch on the donor truck.
That's why I was wondering if the 700r4 had a built in neutral switch and the th350/400 had it on the column. My blazer was a factory 700r4.
I'll dig some more when I get home from work.
 
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Do what ryoken said. While that main plug is off, you can also see if the factory side of the harness/plug has wires that the column side might not. Those could be your neutral safety leads. I'm about 93% sure that the 700r4 itself has no neutral safety switches in it.
 
the neutral switch is at the base of the column for the 700R4, not in the trans.
 
frankin5 said:
If it was auto column and you went to non auto column, you will need to attach the two wires that plugged into the neutral safety switch together for it to start. They will be next to the backup light wires at the bottom of the column
Click to expand...

Pretty sure this is the Park/Neutral Switch you are referring too.

Here is the Neutral Safety Switch wiring for a 1991 (only one I had), you can see that you basically splice into the purple wire with the connector for the clutch switch.
You can find Factor diagrams specific to your truck at this link, there is tons of information.

Capture_zpsezrelhng.jpg
 
Well, I feel like a fool. After checking everything and finding nothing wrong, I figured I would root around in my spare parts and find my auto column that I removed. I found it along with the ignition switch which I removed and noticed its adjustable. So, I went back to the blazer (with the column resting on the drivers seat) turned the key, grabbed the ignition rod that goes into the switch and pulled just a bit harder. I think you know the rest of the story. Also adjusted the high beam switch that mounts on top of the ignition switch, it feels way better with no slop.
Just want to thank everybody for all their help and input. I never would have thought it would be something so easy.
 
Will take some pics when I get home from work. I'm having trouble finding a shift boot to work with it. Might have to end up making one out of an old leather jacket or something.
Took my rear driveshaft into work today. It's leaking bad out of the slip yolk cap. Ran it through our parts washer and JB welded. Hope it works.
 
Sorry no pics during the swap. Almost have it buttoned up. The hurst super boot didn't work, it was too tight and would pop the shifter out of the top gears. Still not sure what I'm going to do about that. Got my rear driveshaft back in after work and topped off transfer case. Hopefully no more leaks.
Front driveshaft double cardan joint was rubbing after transfer case drop, I clearanced all the stops and replaced the pivot ball and socket and u-joints last week at work.
I try to take personal projects in as much as possible to work on at breaks and down time :-)
 
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