Hard start, slow starter - SOLVED Ignitor/Coil grounding

morganism

SunkCostFallacy
 
Joined
Jan 17, 2009
Messages
740
Location
Verde Valley, AZ
Just posted up a hard start thread, and got lots of the regular advice, check cables/grounds, fusible links,
solenoid tests, ignition switch etc. But have noticed this typically happens when the first cold comes. Which made me wonder, how does the FJ60 know when the heater is on?

83 FJ60 4spd petrol USA, aisin carb and dist w igniter and coil on body. Desmogged.

So, it looks like it doesn't know when the heater is on. I have never seen a switch on the H/C slider, and don't think there is one on the 62's either.

From:
Here's what the EWD says:

1. HEATER BLOWER MOTOR OPERATION
THE CURRENT FLOWS CONSTANTLY FROM THE FL HEATER FUSE TO TERMINAL 5 OF THE HEATER RELAY. WHEN THE IGNITION
SW IS TURNED ON, THE CURRENT FLOWS THROUGH GAUGE FUSE TO TERMINAL 5 OF THE BLOWER SPEED CONTROL RELAY,
AND TO TERMINAL 3 OF THE HEATER RELAY " TERMINAL 1 " TERMINAL (A) 1 OF THE HEATER CONTROL SW.
* LOW SPEED OPERATION
WHEN THE BLOWER SW (HEATER CONTROL SW) IS SET TO LO POSITION, THE CURRENT TO TERMINAL (A) 1 OF THE HEATER
CONTROL SW FLOWS TO TERMINAL (B) 16 " GROUND, ACTIVATING THE HEATER RELAY ON. AS A RESULT, THE CURRENT TO
TERMINAL 5 OF THE HEATER RELAY FLOWS TO TERMINAL 4 " TERMINAL 1 OF THE BLOWER MOTORS " TERMINAL 2 "
TERMINAL 1 OF THE BLOWER RESISTOR " TERMINAL 4 " GROUND, CAUSING THE BLOWER MOTORS TO OPERATE AT LOW
SPEED.

So, as soon as the switch is turned to on, the heater resistor is activated, and starts to pull amps. That circuit can pull 10 amps all by itself, though most is converted to heat at low speed. If the fan is on, that is another 1.5 to 3 amps if i recall. You are also automatically energizing the AC circuit breaker. If you have a AC amplifier, it has a disable switch to turn off AC board when to go to crank position, but figure that connection is open.

As our local "output shaft" has shown us...

"The problem is the inefficiency of the blower fan.
The current draw for the slider switch on the HVAC panel is:

Low: 3.3 amp
Med: 5 amp
Med-hi: 7 amp
Hi 10 amp

All of those current draws are accomplished by resistors and low speed will kill most older batteries over night. And even if it doesn't kill the battery, that's a lot of amps to have to replace the next day if you're camping in a spot for a while.

The resistor for the fan is a combination resistor pack located in the air duct near the accelerator pedal. It's located inside the duct because it gets hot as hell when any of the slow speeds are chosen and needs air blowing over it to keep it cool."

Blower Motor Control (out of the box thinking)...

and the A/C amp cutout:

"Well it should first be noted that the spade terminal is not a ground! (See circuit diagram in post #3.) The spade terminal goes to the ignition start circuit in order to disengage the A/C when trying to start the engine"

The A/C Amp Thread

OBD code 51
Cruiser dies while driving

"Power to your 10amp a/c fuse is coming from the 30amp heater breaker. If this goes no a/c and no blower. You can pull the breaker and using a small pin or finishing nail re-set it. If your system was overloaded or someone crossed hot wires up trying to mess with the fuses they could have burned up the ground wires. They are white with a black stripe and all come together in the harness that comes in from the firewall below the dash and feeds the relays. The grounds all are crimped together and go to a larger single wire that bolts under the dash near the fuse box. For me I ended up running a hot wire with a 30a inline fuse through the pass side firewall and to the dash."

"Current comes from the battery through B to the 30amp breaker then to the the relay. when it exits the relay it travels to the fan motor, but it also connects to the 10amp fuse AND line D. Does D draw currents from the ACC post or does it power the ACC circuit? The later would make sense with the second quote.

And in my case it would mean that ALL my ACC connections are being powered buy a jumper wire? Eeek!"

1981 FJ60 - heater fan circuit help needed

fj62 blower motor speed resistors bad


There are also some posts about a "delayed" start, where you can stay on the key at crank, and sometimes it will turn over after 5 sec or so.

So it seems the dust bunny in the room, is going to be the heater resistor package in the duct near the accel pedal. Its always drawing amps, and if the fan is on too, you are losing even more. If you are having a rough start, if those contacts on the coils of the resistors are shaking, you may get intermittents, and that may trigger the AC circuit breaker too. At least that will throw a code 51 if you have an OBD for it.
You are also lowering the current from the ignition switch back to the ignitor for the starter solenoid.

So, ALWAYS turn off fan when turning off truck?

And always test the heater fan resistors when looking for start problems. Seems like if you don't use your AC, you should never push the button for it either, or you may trip that AC circuit breaker, causing more problems.


circuit diagram from a local here, in two parts.

https://forum.ih8mud.com/attachments/wiring-diagram_fj60-usa_1-1980-chassis-body-fsm-jpg.948541/

https://forum.ih8mud.com/attachments/wiring-diagram_fj60-usa_2-1980-chassis-body-fsm-jpg.948539/


A decent hack for cooked resistor, is the old ceramic resistors you find in old TV circuits

Heater/defrost fan switch problem(??)

Heater blower replacement motor thread

AC/Heater blower motor died...replacement?

Getting the heater blower out

Pics for replacing heater core?


and some posts on the 40/55 threads seem to have similar probs.

Intermittant Electrical death-maybe ignition Switch?

For Sale - Rare nos heater blower resistors

Blower Motor Resistor

and a helpful ACC access point on those 40s

What wire is this?



P.S.
and a weird diode up there in the wiring diagram, from the alt all the way back to the dash lights, so the brake lamp on dash at start may be useful for troubleshooting alt/regulator also ?
thanks wptangen

"Anyway, the alternator does not use the charge lamp wire to monitor the electrical system. All it (the alternator) cares about as far as the system goes is that the voltage it generates is in the correct range, and it does this by monitoring the big white wire.

The yellow/white wire only turns on the charge lamp, pure and simple... almost. It also, in my 62, turns on the brake warning and tranny temperature lamps for that wonderful Christmas Tree effect. But in my 62 the connection into those circuits comes after the charge fuse (after the charge light relay, actually). It appears that in your 60 the diode you mention ties into the brake warning lamp circuit; in my 62, this is a red-white wire also connected through a diode. The reason for the diode is that you don't want your charge lamp coming on when you pull the e-brake!

By the way, you are right that the black-yellow wire provides power to the regulator in the alternator. I believe it only receives power when the ignition is on to keep the regulator from draining the battery. I do not know if all yellow-black wires connect into this same circuit or not."

What do the other 2 alternator wires do?
 

g-man

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Joined
Sep 5, 2006
Messages
2,319
Location
Charlottesville VA
I can't see how the heater blower would draw enough to cause your motor to slow start, unless the heater circuit wires were somehow crossed with the ignition wires., but unplug the wires on the side of the blower...this will effectively open the circuit killing power going to the h/c slider, a/c switch fuse ..etc. Another way to do it would be to unplug the heater c/b. Then crank the motor and see if it makes a difference.

In these cases it is usually best to stick to the symptoms. If it is slow cranking then follow the current from the battery to the ignition then to the coil and ignitor. From the coil to dizzy do you have good spark?? You have tested your battery and it stays at 12.5 v while cranking the motor. Is the ignition switch getting the right amount of current? Is the coil getting the right amount of current from the ignition switch? is the starter motor getting the right amount of juice from the solenoid? Are the grounds good? Follow the flow.
 

morganism

SunkCostFallacy
 
Joined
Jan 17, 2009
Messages
740
Location
Verde Valley, AZ
Was turning slowly, then locking on the ring gear. Would have to pull starter, lever ring gear, re-install starter, and try to start again.

Got new coil (didn't install), rebuilt starter contacts, body grounds, fusible links, steering column switches, blower resistor... Stopped before i went to another battery or alt.

Turns out that cleaning the coil holding cage, and running a separate ground wire from the ignitor to the wheelwell solved all starting probs. Not a single hiccup for nearly 6 mos now, even when i leave fan on. So add that to the list of ground checks...
 
Joined
Oct 27, 2009
Messages
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Location
Front Range Colorado
@morganism do you have a picture of the ground wire you added? My igniter looks like it’s got a clamp on it and that clamp is tied to the fender providing a ground. Does yours have this too, and you had to add another ground wire?
 

morganism

SunkCostFallacy
 
Joined
Jan 17, 2009
Messages
740
Location
Verde Valley, AZ
I just made a double crimped wire a couple feet long, and ran it over to the wheel well body, there was a free 10mm threaded hole there.

The ignitor has a tiny ground wire from the inside of the case to one of the exterior corners, put ground wire on the other.
Yes, the coil and ignitor are supposed to ground thru the mounting cage, and the hold down bolts. They are obviously oxidizing, and the bolt holes get crusty. Then you have a huge amount of voltage trying to get out, and you can get interesting paths. My breather hose from dist cap was giving me shocks.....

Still no start probs now, coil still in its box. Headlights are brighter too, and i get single pump o pedal starts every time.
 
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