knac1234

Hi all,

Other than starting issues, my 86 manual trans basic pickup (55K miles) runs like a clock!

I posted this a couple months back, but I thought that a new battery cured my issue (old was registering 10V and was 6 years old)…...until now.

Issue:
When turning the key to START, sometimes it starts/engages the starter motor, but now, more often than not, it will not start or will not start until after many, many turns of the key and possibly luck!

Symptoms:
-I thought the clicking noise I heard when turning the key to start was the starter relay on the passenger firewall. It was actually the clicking of relays in a plastic fuse box just in front of the starter relay (2 relays and fuses in this box).
-I removed the starter relay per RAD4Runner's thread and cleaned the contacts that should come together via the electromagnetic armature setup when the key is turned. The contacts did look clean, but I cleaned them anyway.
-I reconnected the starter relay without the metal housing to observe it while my wife turned the key. No clicking (just the other 2 relays in the plastic fuse box), and visually no movement of the contacts via the armature.
-I then had her turn the key again while I manually pushed the contacts together in the starter relay and the truck instantly started.
-I then removed the relay again, and tested it by connecting power to it from another car battery. The contacts operated properly.

So, at this point, I know that the battery is good (rechecked at just over 12v); and the starter relay contacts are clean and it operates properly.

So, in my opinion, there must be some issue in getting power to the starter relay itself when turning the key as, again, I can close the contacts by hand on the relay to start the truck.

Any ideas???

Thanks in advance,
Julian

old87yota

It looks like you found some of RAD4Runner's posts on the subject. That is good.

A little bit further, he shows a factory wiring flaw with the starter relay here:https://www.yotatech.com/forums/f199...l#post51975700

The factory design flaw puts full starter solenoid current (~ 12 Amps) through the ignition switch and through an unnecessary length of wiring. RAD4Runner's modification shortens the electrical path and removes the high current off of the ignition switch (replaced by the low current draw of the relay coil) and thus provides a better, more robust electrical path than factory and helps preserve the ignition switch.

However, even with the flawed wiring, the starting circuit should still work (it has for over 30 years, right?).

Do you have a multimeter (or test light) and know how to use it?

If you do, I would first try and find what exactly is causing your power problem to the relay before doing any modifications. Why? While the modifications have solved many click, but no crank issues, it does not fix every potential starting issue.

From your description, you are missing either power (+) or ground (-) to the starter relay coil. This could be due to a bad ignition switch, bad wiring, poor connections, bad clutch pedal start switch, etc.

You said that with the relay installed in the factory way (but no housing) and you manually push the contacts closed, the truck will start just fine. Since the relay coil and contacts get their power from the same ignition switch contact, this proves that power is getting all the way from the battery and through the ignition switch. Since I do not have a starter relay in my truck, I do not know where the wires physically split off from the ignition switch to both the contact and coil sides of the relay.

There should be ~12 volts on pins 3 and 4 on the starter relay when the key is in the start position. RAD4Runner's post above has a pretty good description of what should happen in both the stock and modified forms.

RAD4Runner

Nice troubleshooting technique.

Below seems to be your problem.
Does starter relay click when you use clutch safety cancel switch?
To eliminated doubt on clutch safety switch, disconnect it and jump connector pins on the harness side. Then try cranking again.

Once you figure out why starter relay does not click, the wiring flaw still needs to be addressed. $11 worth of parts.

knac1234

Thanks guys!

I thought my troubleshooting was fairly creative too!!

I will try the clutch safety cancel switch idea.

That said, power must not be getting to the starter relay (due to clutch safety switch) or perhaps at the key? I will eventually do the $11 fix, but will a new ignition switch likely cure that segment of wiring/power delivery issues??

https://www.autozone.com/batteries-s...18851_618601_0

Without rereading the $11 fix yet, my other thought was to put a push button switch in the cab that delivers power to the starter relay (akin to my finger closing the contacts which started the truck) as a temp solution also.....

Julian

87-4runner

I did the push button as a permanent fix...
i like the fact that you can't start my truck with the ignition switch and have to know where my push button starter is....a anti theft deterant...

RAD4Runner

Not creative enough. LOL!


Only if it is what is causing your problem. YOu're already on the right track. Don't start blindly throwing parts at the truck like many incompetent shops do.

Push-button like a Prius? LOL!
Push-button TO THE STARTER RELAY coil positive will send power to it independent of the ignition switch, but IF the problem is on the negative side of the coil it still will not fix your problem.
A push-button to the starter relay positive may energize it and close the contacts but will still not solve the "wiring flaw" that was done AT THE FACTORY.
If, AND ONLY IF, you want a short-cut, wire the output of the pushbutton to the male spade terminal on the starter solenoid.
But then you would still have a problematic part somewhere that can get worse and bite you when you least expect it.

Troubleshoot and fix it properly.

knac1234

LOL...…that relay pic with the bloody BFH cracked me up!

Turns out that it was the clutch safety switch causing my starting issues.

I had my wife try to start the truck without me engaging manually the now known good starter relay. Of course, it did not start. I then had her try to start the truck while I pushed the plunger all the way in on the clutch safety switch, and it started right away. With that knowledge, I had her press the clutch pedal fully down while, using a flashlight and mirror, observing the movement of the plunger on the clutch pedal switch while the clutch pedal was being fully depressed. There was hardly any movement at all. I adjusted the switch so that the plunger could be properly activated by the pedal when depressed, and.....problem solved!

Thanks for all of your help! Drove the truck about 120 miles today with multiple stops and NO starting issues

Julian

RAD4Runner

LOL, but based on true Yota events.
Don't forget the starter relay wiring flaw. Help extend the life if your ignition switch ST1contact.

ev13wt

Fix the wiring or throw reman starters at it until you find one that works fine. It is possible.

OR

Do it like I always do it when I'm too lazy. Keep clicking that "start" position.
Get out and move the truck in gear so the flywheel moves a 1/4th of an inch.
Scream at it.
Get out and push start it.

RAD4Runner

The problem is in the starter relay wiring, so smoothly operatiing starter solenoids would only mask it, as they have for years.
Putting it in gear or out does not matter, either, because wiring problem occurs BEFORE the solenoid plunger pushes starter gear to engage with flywheel. Therefore, there is no connection between starter and engine nor transmission when the wiring flaw manifests.
Wiring problem is also slowly kiling the ST1 contact of Ign switch.
I explained it all on my post.