70s Power Wagon Ignition switch info needed !!

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NCmtnDWELLER

NCmtnDWELLER

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Greetings and Salutations
Have a new problem electrical of course truck sets a few days and it will turn over but not crank or fire !
Put battery charger on and it fires instantly - replaced battery but wasn't issue , and noticed while trying to start it WITHOUT battery charger hooked up when u release ignition switch and click to off motor turns a little the opposite direction!!!!
Trucks is a 76 model so went ahead and bought a new ignition switch but upon opening box unit just inserts into column nothing electrical visible on it but it's bought and going in ASAP any thoughts on main issue thanks.
 
Ok
I have many of those so will try that , pretty sure I installed a new one a few years ago but probably Chinese quality so that's why I keep a spare in truck , thank u
 
SS Lancer said:
Greetings and Salutations
Have a new problem electrical of course truck sets a few days and it will turn over but not crank or fire !
Put battery charger on and it fires instantly - replaced battery but wasn't issue , and noticed while trying to start it WITHOUT battery charger hooked up when u release ignition switch and click to off motor turns a little the opposite direction!!!!
Trucks is a 76 model so went ahead and bought a new ignition switch but upon opening box unit just inserts into column nothing electrical visible on it but it's bought and going in ASAP any thoughts on main issue thanks.
Click to expand...
You say it will turn over, but, not crank......isn't that the same thing? Have you measured the voltage to the coil/ballast/ECU while cranking?
 
cudamark said:
You say it will turn over, but, not crank......isn't that the same thing? Have you measured the voltage to the coil/ballast/ECU while cranking?
Click to expand...
Turns over yes appears to ROTATE crank in normal fashion however it's not firing / soon as u put charger or another vehicle with jumper cables on battery fires instantly
 
I would start by checking battery voltage while cranking. Then I would do a voltage drop test between the pos. battery and the ignition module while cranking. Then from the neg. battery to the ignition module base that should be grounded to the body. Diagnose before replacing parts.
 
The ballast resistor has always been misunderstood, and blamed for everything under the sun.
In this case.... I don't think so!
 
Thank you for stating this info. Now the Original poster has YOUR opinion and also my suggestion.
 
bobsgtx said:
I would start by checking battery voltage while cranking. Then I would do a voltage drop test between the pos. battery and the ignition module while cranking. Then from the neg. battery to the ignition module base that should be grounded to the body. Diagnose before replacing parts.
Click to expand...
Ok thanks digging in sat on issue
 
If the engine is "kicking back", the timing is probably off.

Extra volts/amps is allowing the starter to "push through".
 
Max1196 said:
Thank you for stating this info. Now the Original poster has YOUR opinion and also my suggestion.
Click to expand...
Sorry not just an "opinion". I've worked on my share of these too.
Not at all trying to start "shut". Trying to help the guy like everyone else.
Did the op ever get that new ign switch?
I've dealt with ignition switch issues over the years too. .on those you can just plug the new switch in under the dash and work it in your hands and see if it does anything without pulling the column apart. This was before they put the switch further down the column and actuated by a rod. I'm guessing yours isn't a tilt column?
 
The most common thing I see with those style of ignition switch is they get loose and either barely reach the "crank" position or they don't "spring back" from that position. The spring inside breaks or wears out and no way to fix that except for replacement. You'd certainly destroy the switch further by trying to dismantle it to do something about those issues.
I've bought a couple via eBay brand new but probably 25-30 years old. Much better quality than current new stock and in most cases cheaper. Back then the"standard" brand was pretty good.
 
I just reread the first post, you bought the key part of the ignition switch? You're right. Nothing electrical there. Won't help you much.
Usually they ask at the parts store if you want the key part or the electrical part when you ask for an ignition switch.

Another thing to check. So you have those replacement battery cable ends with the "mickey mouse ears" on them? You know, the 2, 1/4" bolts that hold a metal strap on to pinch the bare cable ends? Those suck. I've also had the positive side cable turn to nasty green. "dust" within the insulation and not be able to carry near enough current thru it. I make my own cables, crimp copper lugs onto the cable and bolt those lugs to the "mickey mouse ears" on those terminals. And heat shrink the terminals.
 
YY1 said:
If the engine is "kicking back", the timing is probably off.

Extra volts/amps is allowing the starter to "push through".
Click to expand...
Ok thank you that is probably the whole problem / I put more timing in system a few months ago and sorry didn't connect the 2 together because starting issue occured a few weeks after timing change but your probably spot on I will retard timing some tomorrow and report back - thank u.
 
I always set my timing by ear/feel.

The car will tell you where it wants it.

Advance until it pings under hard acceleration, then back off until it stops.

If that causes a hard start, something else is wrong.

Book spec is theoretical.
 
YY1 said:
I always set my timing by ear/feel.

The car will tell you where it wants it.

Advance until it pings under hard acceleration, then back off until it stops.

If that causes a hard start, something else is wrong.

Book spec is theoretical.
Click to expand...
Thank you Sir - silly as it sounds put a little more timing in truck/ambulance
1976 886 Power 1/1/4 ton heavy vehicle trying to squeeze as much mpg as possible and I live up @ 3500 ft elevation and hear slight pinging when it was hot last month so that's probably my problem I will retard it slightly maybe around 2° and see how it responds & Thank u.
 
Here u go

IMG_20231020_111040_MP.jpg
 
SS Lancer said:
Greetings and Salutations
Have a new problem electrical of course truck sets a few days and it will turn over but not crank or fire !
Put battery charger on and it fires instantly - replaced battery but wasn't issue , and noticed while trying to start it WITHOUT battery charger hooked up when u release ignition switch and click to off motor turns a little the opposite direction!!!!
Trucks is a 76 model so went ahead and bought a new ignition switch but upon opening box unit just inserts into column nothing electrical visible on it but it's bought and going in ASAP any thoughts on main issue thanks.
Click to expand...
 
Ok well had way to much timing in engine which was addressed today.
Truck has a medium sized inverter installed @ REAR and noticed even with unit OFF while changing battery once wire leed was connected it sparked and must have been pulling enough on battery that once truck sets for a few days it's enough to drastically drain battery.
Appears all is well now and thanks for the professional advice etc.

IMG_20231023_152653_MP.jpg
 
Max1196 said:
@volaredon , care to explain the RED X ?
Click to expand...
Ballast resistor is bypassed during start.**

How it works, using a points system for the example.

1. When the key is turned to start current flows through to the key switch and then splits,
a. Some current takes the path of the S2 wire (yellow) to the starter relay, through the neutral safety switch to ground.
b. Some current takes the path of the J3 wire (brown) to the coil whenever the distributor points are closed.

1698235648343.png

Take your finger and trace the path to the coil.

The rest of the sequence to get the starter turning happens very quickly.
2. Power through the relay's bottom terminals internally connects the big stud to the solenoid terminal. Current flows from the battery to the starter's solenoid.
1698235880739.png



3. The starter solenoid (inside the starter) closes and the starter draws battery battery power to spin it.
1698235908630.png


The starter draws a lot of power.
Battery voltage will get pulled down during starting, but if it drops to 9 V its probably not going to start. Recharge the battery with a charger.


**With electronic ignition, the 1/2 ohm resistor is needed for the ECU to get power during start.
1698236240327.png
 
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