weird starter issue

[s3landy]

Short story; put dual batteries in my 130, cranks great but then the original starter started to act up when cold. The solenoid would not kick out far enough to engage the flywheel and it would just spin. Once in a while it would catch and start.

Pulled starter numerous times, cleaned, filed brushes, emery clothed armature, checked everything etc. All looked good, but installed and the same problem when cold(-20ish).

Bought new starter and it is doing the same thing. Got me stumped, anyone have any ideas?

Thanks,

Mike

[Red90]

Have you checked the battery ground to the engine?

[s3landy]

I will check tomorrow and post, thanks

[headdamage]

Check battery cable conections and the cables themselves for corosion. Old cables can develop internal resistance due to corrosion. Ground cables and conection to.

[s3landy]

I don't seem to have a ground strap to the engine itself. My ground strap comes from the battery to the exhaust hanger and then carries onto the transfer case. I cleaned both of those connections. The cables themselves look good and not corroded on the batteries. I never had these issues when I had a single battery, that is why it is so strange. I had to go somewhere first thing this morning so I won't know until later tonight or tomorrow whether my cleaning the connections helped.

Mike

[Red90]

Perhaps it is something you did with the dual batteries. How exactly are they wired up?

[s3landy]

I just wired them in parallel

[Matt H]

The ign switch could be failing. They fall apart internally and cause exactly this problem.
My 2c.

[s3landy]

I did think of that and tried a jumper direct from the battery.

Mike

[ugly_90]

I had a similar fault with a failing replacement aftermarket ignition switch in my 90. the troubleshooting was much simpler for me, looking at the back of the switch, it was already falling apart. I replaced with genuine Lucas, and its running again.

Do you have a voltmeter to go over the circuit and record voltages to chassis?

I assume you already have the wiring diagram for that truck.

A very useful tool in DC electrical is the DC-type clamp-on ammeter, which will allow you to step through the problem and record currents, without disconnecting anything. The DC variant clamp-on is more expensive and rarer than an AC version, you may have to borrow that tool. I have found it only affordable as an aftermarket meter. Most clamp-on ammeters are AC only.

[Matt H]

I'd be looking for a high resistance to the pull in solenoid circuit.

[s3landy]

Well, no joy today, cleaning the grounds never helped. Onward I will look.

Mike

[Red90]

There may also be a relay in the start circuit. It depends on the year and engine. If so, it is worth checking.

I agree the ignition switches are prone to failure and only to use OEM (Lucas) branded switches.

[s3landy]

I did some testing today and this is what I found;

Voltage readings;

Batteries-12.79v
Large wire on starter-12.44v
ignition wire(on starter)solenoid-11.4v

Ignition switch(power in)-12.44v
ignition switch(power out-access)-12.08v
ignition switch(power out to solenoid)-11.4v

It seems that the ignition switch is causing the drop? Could this be, not quite enough voltage to engage the solenoid all the way?

Can it be taken apart and cleaned/fixed, or is it better to just order a new one?

Mike

[Matt H]

Are these readings the voltage drops while cranking?