Scatterbrain

87 4wd 22RE .So this problem may just be a simple fix, but I want to make sure I know what I'm dealing with. A while back I wasn't able to get the thing to actually start up, and we figured out it was the circuit opening relay switch, as we eventually got the fuel pump to start working by bridging the circuit.

Now, the alternator is about a year old, but as I recently purchased the vehicle, I'm unsure about the battery. Now went I attempt to turn it over, I get very faded lights, and all I can hear is a clicking and low buzzing noise while I'm trying to crank it, which seems to originate from behind the glove box.

If jumped the car will start up, and unless the relay switch is bypassed, the engine would stop running after a few seconds. As long as I can keep the bridge in it stays running. So I know that's one problem.

When we tested the battery it read 12volts. But it still wont even try to turn over unless its jumped by another vehicle. It's started getting cold here recently (colorado), and I'm wondering if this may have something to do with it....All in all...I know alternators(even new ones) can go bad any time, and even though a battery reads 12v it may be old and close to death...Does anyone have any ideas as to what this might actually be? I feel this can't all be due to a bad relay switch, but I'm not that mechanically inclined, especially when it comes to electrical work..Thanks!

RAD4Runner

• A problem well-stated is a problem half-solved.
• Our senses and a volt-meter are the best diagnostic tools

1. What is your battery voltage when nothing is on?
2. What is the voltage measured at battery post (not the connector) when high beams are on?
3. What is the voltage measured at battery connector (not the battery post) when high beams are on?
4. What is battery voltage when you try to crank the engine?
5. What, where and exactly what is clicking? buzzing?

You would have to do checks above before we can help.

YES, 2 & 3 above matter because difference in those 2 & 3 readings will indicate poor connection to battery (i.e., corrosion where battery post contacts connector)

What relay switch do you mean? If Circuit Opening relay, that's the click you hear behind the glove box. Bad C.O.R. will keep truck from having combustion (the VROOM), but it will not, and never will, keep truck from cranking.

To help troubleshoot, starting and charging systems are explaned on link in my sig.

Best of luck.

vital22re

iTrader: (2)

battery could be reading 12 but have a bad cell and not have enough to start. Have battery load tested, check/clean all battery connections. More than often its a weak ground or corroded terminals.

RAD4Runner

Agree.
However, turning headlights on and checking battery voltage is a mild form of load-testing that OP can do before he heads over to the shop, especially if he cannot start truck.

Scatterbrain

Ok.
-So with the car off the battery reads like 12.3
-When on, the terminals read about 11.9
-Connectors at 9sh
-With headlights the terminals still read around 11
-Connectors dropped to 5.5

-When the headlights were on with the car off I could hear a clicking coming from some sort of housing just above the battery, like a black box.

RAD4Runner

A lot of difference between battery post itself and connector indicates you have poor contact between battery post and conenctor, possibly from corrosion. You need to have bare metal to bare metal contact, meaning grey metal is not enough. Gotta clean metal to see steel and lead color.

See this post for details.

See what happens after you clean contacts. If still no improvement, take to take to Auto store for load testing.

That's your headlight relay energizing. Expected behavior.

Whether you get problem solved or not, I recommend you fix the flaw in starter wiring mentioned in my signature. Many are lucky enough... they have low resistance circuit, wires in good condition, clean starter relay and ignition switch contacts, strong batteries, and mechanically smooth starter solenoid, that they do not experience the problem. However, problem could strike anytime.

Scatterbrain

Thanks, I'll clean and reset the connectors and check back in. Might you have a guide for finding the circuit open relay switch? I'm trying to replace that as well.

RAD4Runner

Circuit Opening Relay (COR) is behind glove box. pls search my build thread.

Scatterbrain

***Update***

Resat the connections, and problem has actually worsened. I believe this to be caused by the stress I've been putting on the battery. Now I'm bright lights outside and on dash, unlike the dim lights when the problem first arose. However, the car is no longer starting when jumped...No matter what, I can just hear the start click when I try to turn it over. Sort of screwed I can't even get the thing jumped.
I'm unable to pick up the relay switch until Monday. I made a bridge to bypass the relay to turn the fuel pump on, is there another way to possibly bypass the entire switch so I may be able to temporarily start it up, so I can take it to a shop?

RustBucket

iTrader: (1)

I think a fresh battery should read about 12.6-12.7 V. I would be worried by 12.3.

RAD4Runner

Scatterbrain,

Let me ask you again:
What exactly is clicking? And when?
C.O.R behind glove box?
Starter relay?
Starter solenoid? Solenoid piggybacks on starter motor.

What relay switch are you talking about. The C.O.R.? Let me reiterate... see my post on how cranking system works and you will see that C.O.R. has no effect on cranking. C.O.R. is for powering the fuel pump. You're not even there, yet.

Don't jump from one problem to another.
Fix power problem first.
Then cranking (starter turning)
Then combustion (when it goes VROOM!)

Re power:
Yes, your battery could have already drained from repeated attempts at cranking. At least take battery to store for load testing. That would eliminate or confirm it as suspect.
Yeah, battery is suspect, too. Even a weak battery can power lights. However, it will not be able to turn a starter that requires a lot of power.

After you verify that battery is good, figure out cranking issue.
To help narrow down where to look, do this test. This will tell you whether to look from starter solenoid, its contacts, and to starter motor, OR starter solenoid coil, back to starter relay, to clutch safety switch, to ST1 contacts of ignition switch.

To help you understand exact sequence of events leading to starter turning, so you do not have to guess, see link on, my sig.

Then, let's go from there.

RJR

RAD4Runner's advice is good stuff. But, before you yank the battery, there are a few more voltmeter tests you can run. You'll need an assistant to turn the key while you look at the meter.

1) Put your probes on directly on both the positive and negative posts (not connector) of the battery. Measure the voltage - should be about 12.5 volts. Now have your assistant turn the key to start. Watch the voltage. If it drops below 10 volts your battery is discharged or bad. If it doesn't drop much at all you still have bad connections somewhere in your cables. If it's the latter, continue to step 2
2) Put one probe on the negative battery post and the other on the truck frame. Have the assistant turn the key to start. The voltmeter should read less than a volt. If more, you have a bad ground connection. Could be at the battery terminal, or where the large ground cable attaches to the engine frame, or it could be a bad cable. Cables corrode inside the insulation where you can't see it, but it causes high resistance and keeps your starter from working.
3) If the ground side checks out, make the same tests on the power cable, between the positive battery post and the place where the big cable attaches to the starter. If there's a big drop, you've got problems in your positive side cable or connectors somewhere.
4) If the positive side checks out, continue with RAD4Runner's more detailed troubleshooting process. Sooner or later you'll find where the voltage is getting lost.

To summarize, when a starter clicks but won't turn over, it's almost always because it's not getting enough voltage to fully operate. That usually indicates either a weak battery or poor connections. On old vehicles like the ones we love to drive and work on, poor/corroded connections are common and can show up in lots of places the new car folks would never think to look. The tests above are a progressive way to divide the circuitry until you can find the problem area.

old fart

At the shop I work at when we test a battery, car off, we test for 13.1-13-7 volts. With the car/truck on, we test for 14V, and that's with the a/c on (if it has a/c), high beams, blower motor on high, anything we can turn on to load the system, as most of you said above^^ there.

Scatterbrain

Thanks for the tips! Sounds like some good troubleshooting advice. I'm not engineer, and again minimally mechanically inclined, so splicing cables and creating various testing cables is beyond me. I can at least try these suggestions out though.
I went ahead and took out the circuit open relay, and it was literally completely rusted and corroded. I found one for like $50 and had it shipped to the store, should be there in the morning..
***Just an FYI for anyone who may be looking, the COR for an 87 4runner 22re, is BEHIND the ECU. Don't have to fully remove it, just unmount it..Everything I could find said it was above the ECU, or next to it. ***
-Starter relay is also working-

Rad I know you said the COR only controls the fuel pump, but it's diagram shows
various connections to many parts of the electrical system, including ignition. My room mate seems to believe this could be the cause, but as I'm switching this out anyways, I'll continue to diagnose.....I'll try the suggested steps tomorrow, and try to get my battery load tested while I'm out. I'll report back with my findings. Thanks again for the help!

RAD4Runner

Concur with RJR's checks^^. Best practical way to test starter and ground cables.

How do you know starter relay works?
You still have not answered my question: Does the starter solenoid click?

This is a test for the complete alternator AND battery system.
From FSM:
Unless one has bad wiring, voltage at battery post, battery connector, and "B" (thick white on screw-post) output of alternator will be almost the same.
With engine from idle to 2000RPM, Voltage at B should be:
13.9 to 15.1 V @25°C (77°F)
13.5 - 14.3V @115°C (239°F)
Temp is probably engine compartment temp.

that's what fellow forum members are here for

Understandable. Watch out for leaks, possibly around the grommet where wires from engine compartment enters the cabin. Splashes from the road could get in there and get components wet/rusted/shorted.

You sure? You can see it from inside the glove box (here) without removing ECU.
It has "Circuit Opening Relay" clearly printed on it (here).

I understand. Wiring could get confusing; that's why I explain exact sequence of events that cause one thing to happen (i.e., starter turning), AND clearly distinguish that sequence from others that just happen to occur at the same time. For example, turning ign key to "Start" position turns the starter, AND at the same time energizes the C.O.R. so you hear the C.O.R. click. However, whether C.O.R. works or not will not affect starter turning.

Connection with the rest of ignition circuit powers the C.O.R. and Fuel Pump. But C.O.R. will not prevent cranking system from working. I hope that's clear enough, so don't chase the wrong things while troubleshooting.

Scatterbrain

SOLVED!!!!

Ok....so this is embarrassing...but since you kind folks did attempt to help me fix the problem, I'll share my moment of idiocy...
So when I resat the connections on the battery terminals......guess what I forgot to re-attach.....yeaaaaa the start cable to the positive terminal. I was just drinking a beer...and staring under the hood for like half an hour....and suddenly noticed the lack of a large cable extending to the battery....I feel so dumb >_<
Sorry for wasting everyone's time, but at least I learned a few things....
In retrospect...it now stays running since I changed out the relay..
I suppose the battery just needed to charge for a whole, and that's why it wouldn't start. Probably time for a new one anyways. Winters a-comin

**RAD I'm positive the COR was behind the ECU, HOWEVER, it was hanging and unmounted, so it could have initially been above it I suppose. Yet I attempted to remount it and it was literally impossible based on the short connections, so there it will remain to hang**

Gamefreakgc

Haha, glad you figured it out! We've all had those moments... I left the plastic cap on my new battery and couldn't figure out why it would die every time I turned off the engine...

RAD4Runner

Good it worked! We all got beer to thank for, don't you guys agree? Cheers!



LOL! WOW! Wonder how you started the engine in the first place