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Diagnosing A No Start/Slow Start - Starter Concerns

ExplorerDMB

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City, State
Mechanicsville, Virginia
Year, Model & Trim Level
2004 Acura TL
The Thing Just Won't Start



Introduction

In this write-up you will find out how to diagnose a No Start/Slow Start condition. With a lower mileage car, most of the time it is just your battery that is either dead or you don't have enough amps to do anything. For you all with an older vehicle with a good amount of mileage, your problems can be the following: Battery, Starter, Solenoid, and/or Wires (connections). To first get anywhere, you need to understand the basics of a starting circuit.

Finding Your Way


Symptoms:

"Click-Click-Click" - Refer to the Voltage Drop Testing section (usually a bad/dead battery)

Slow Crank/No crank - Refer to Amperage Testing section and diagram at the bottom
The Basics

Most modern cranking circuits include a Starter Motor (an electric motor that can develop nearly 8 horsepower for a very short time when first cranking a cold engine), a Battery (must be at least 75% charged to make the cranking circuit work properly), a Starter Solenoid or Relay (turns the starter on and off), Starter Drive (inside the motor, made up of a shaft and pinon gear on the end which engages into the engine flywheel and rotates the engine), and Ignition Switch (controls the starter motor operations)

Everyone Loves Pictures:

Starter Drive (w/ Pinion Gear):

starter3.jpg



Ignition Switch:

ignition_switch.jpg



Starter Solenoid:


Most vehicles are equipped with a neutral safety switch which allows the vehicle to be only started in park or neutral on an automatic transmission. The clutch pedal takes place of this switch in a manual transmission. Starters work on magnetism, by field coils and magnets, which build up current that turns and causes it to spend the motor over.


Voltage-Drop Testing

Voltage drop is the drop in voltage that occurs when current is flowing through a resistance. If voltage drop is too high, which can be caused by dirty battery terminals, might inhibit the ability of the starter and not allow it to operate.

Step 1:

Connect the positive voltmeter test lead to the most-positive end of the cable being tested. The most-positive end of a cable is the end closest to the positive terminal of the battery.

Step 2:

Connect the negative lead to the other end of the cable being tested. With no current flowing through the cable, the voltmeter should read zero because both ends of the cable have the same voltage.

Step 3:

Crank the engine. The voltmeter should read less than .2 volts

Step 4:

Evaluate the results. If the voltmeter reads zero, the cable being tested has no resistance and is good. If the voltmeter reads higher than specified, then the cable should be replaced. But, before replacing, check connects of the cable to make sure they are clean and tight.

TIP: If a cable is hot to the touch, there is electrical resistance in the cable. Touch the battery cables and while cranking feel for heat. If any cable is hot to the touch, it should be replaced or cleaned.

Also, you can test right across the battery. You should have around 12.6 volts for a fully charged battery and when the starter is energized, it should cause the voltage to drop down to about 9-10 volts.

Voltage Drop Testing Diagram:

22915StartingCircuit.jpg




Starter Amperage Test

To test for amperage draw, an AVR is the easiest tool to use. To test correctly, you must have a 75% or more charged battery to get an accurate reading. Connect the positive and negative leads of the AVR to the battery in the correct position, and then put your amp probe/clamp on the negative battery cable. Begin to crank the engine and read how many amps are being drawn from the battery. Here is a general maximum amperage draw chart for testing a starter on a vehicle:

Four Cylinder: 150-185 amps
Six Cylinder: 160 to 200 amps
Eight Cylinder: 185 to 250 amps

What will an amp reading tell you? It should tell you if the starter is good or not. If it is drawing too much current/amps, then it is severly worn and needs to be replaced. Excessive current draw indicates one or more of the following:

1. Binding of starter armature as a result of worn bushing
2. Oil too thick (viscosity too high) for weather conditions
3. Shorted or grounded starter windings (inside starter) or cables
4. Tight or seized engine
5. Shorted started motor (usually caused by fault with the field coils or armature - which is inside the starter)

You can also use a multimeter with an amp clamp to read the amperage draw of a starter.

Typical AVR Machine:

(Photo Link Is Dead - Edited by Admin)


Ohm Out A Solenoid:

To testing the solenoid with an ohmmeter, connect your leads to the starter terminal (usually smaller in size) on the starter and ground your ground lead to the starters casing. should be .4 to .6 ohms (winding check). Then check from the starter terminal to the motor terminal and it should be .2 to .4 ohms (winding check).


Here is a helpful chart:

22915StartingCircuitTroubleshoot.jpg





TIPS

Don't Hit It: In the past, it was common to see people using a hammer to beat on the side of a starter to "free-it-up", and it would sometimes work. However, most of todays starters use permanent magnet fields, which can be broken if hit hard enough.

Watch The Dome Lights: Whenver diagnosing any starter-related problem, open the door of the vehicle and observe the brightness of the dome or interior light(s). The brightness of any electrical lamp is proportional to the voltage. Normal operation of the starter results in a slight dimming of the dome light. If the light remains bright, the problem is usually an open circuit in the control circuit. If the light goes out or almost goes out, the problem is usually a shorted or grounded armatuer of field coils inside the starter or possibly a bad battery.

One Of My Stories: My parents called me up one day and my dad says "hey listen!" and puts the phone near the cranking engine and all you hear is "click-clack-click-click" and all this harsh noise. At first I was running through all of my thoughts of what exactly it could be since we replaced the battery about a year ago. Well, then I thought about the mileage on the vehicle (around 68K) and then a few other things. When I got there it became more obvious; you open the door and the light are hardly dim and would die out as soon as you tried to start it. Which indicated to me a battery or starter problem. I didn't have a voltmeter with me, so we took the battery out and went down the street to autozone and got it tested. When a load was put on it, it went down to like .56 of a volt. Obviously that isn't enough to start a vehicle. Most starters run on 2-3 volts. We got a new battery for free (under warranty) and was on our way. Put the new battery in and it fired right up.



Good luck. Hopefully other people will put in their information and their expierences.

-Drew
 



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Ooooooo. Can we get a sticky or a useful thread designation on this puppy?
 






Yay ! I nominated this as a Useful Thread and gave it 5 stars. This Forum gets even more valuable with picture posts like this one. THANKS Drew!
 






Glacier991 said:
THANKS Drew!

My pleasure. I had some free time, and had a few books with good diagrams, so I just felt like the site could use something useful. Hope it'll save someone some time/money

-Drew
 






Well, though you make it sound like an afterthought you managed to pull off in just a few minutes, I KNOW the investment of time and energy and thought this takes. When knowledgeable folks contribute these kind of posts it only makes the site get better and better. A great place for folks with some background and knowledge (you certainly qualify) to help younger curious folks. Ya know autoshop is mostly a thing of the past and places like this are where we pass it along. Once again, good going! Nicely done post. (notice your 5 stars?)
 






Glacier991 said:
(notice your 5 stars?)

yeck yeah - thanks. It's what makes it all worth it! ha Thanks for the kind words and the 5 stars

-Drew
 






Glacier991 said:
Yay ! I nominated this as a Useful Thread and gave it 5 stars. This Forum gets even more valuable with picture posts like this one. THANKS Drew!

Since your a mod now - can't you make it a "useful thread" -- Congrats on that also

-Drew
 






Officially a "Useful Thread"... and stickied in the Under the Hood Forum...keep up the good work. And thanks!
 


















When starting my x I get the click and my instrument cluster is also flashing when I try starting the vehicle. Anyone know what the problem can be? CMAX~
 






I'm confused!!!

93 Explorer Eddie Bauer, stock. I have an intermittent starting problem. When it does decide to start (before today!) it starts just fine like it should. If it doesn't decide to start, I here the click, have plenty of power and things appear to be working properly. This is what I have done.

Did the voltage drop test, 0 volts with no load and 0.1-0.2 with load. Ended up taking the cable off the starter, cleaned it (was pretty clean to begin with) reinstalled and tested again. The nut was a little loose, now it is tight, after testing again no change.

Didn't touch cable while turning the key yet, my helper had to get going.

Before we started to play around today battery was 12.26v, 65%. Later, tested across battery 11.9v no load and it did drop to 10v while turning the key.

Will do this one soon I hope (bad weather now). Fender relay: disconnect push on wire, jump a cable from positive battery post to "bat" post on relay. In the middle of typing I almost did this one, which one is the "bat" post, my books don't say and I can't see any markings on it (I haven't removed the relay yet, hopefully won't). With the key in and engine not running I had 12v on both? post's I think.

Tested starter cable. I assume the top post is b+. Positive lead on that post and negative on ground, I had 12v. Is it worth it to properly test with ground on the starter case? Intermittent starting though. No ground would mean it won't start at all?

After testing today, if it decides to start I would sometimes get a very slow start. It doesn't sound typical of a low or dead battery, maybe the starter is slowly dying? I have been stranded a few times (this time I'm at home). First time when stranded I did some test's didn't change anything or remove anything, decided to turn key before I go underneath it and it started. Once I tapped the starter it started fine. The next time it didn't do anything, later it did start though.

I don't have the proper tools for an amperage test just a multimeter. I expect to "ohm out a solenoid" tomorrow. Dad mentioned that he recently had a shorted cell in one of his camping batteries, volts were good but no amps. Is there a "cheater" test that would indicate a amp problem with my battery (maintenance free). I live in small town, not sure where to take it yet.

I appreciate any help. It might be an obvious one for some of you guys, I'm completely stumped!:mad:
 






88 ranger wont start

hey hers my problem i have a 88 ranger 4X4i put a 3 inch body lift in it, sence then it wont start with the key it does nothin no click or anything, it will start if i turn the key on then cross the seleniod over, i changer the seleniod checked the grounds hand stilln have no idea anyone heve ideas
 






88 ranger wont start

Did you change the starter solenoid or fender relay? My 93 explorer has both. It could be a lose connection somewhere. I would also check your battery. If it is less than 12volts it obviously isn't fully charged. The point is, you could have a dead cell in the battery.
1.Make note of the voltage on battery. 12v=%40, 11.8v=%30, 11.7=%20 charge. 11.6v is less than %0 in the battery!
2.Charge it for awhile and test for volts.
3.Then start truck normally.
4.Test battery again, if volts dropped below volts in step one again then you probably have a dead cell. Borrow a battery to confirm?
 






04 Mountaineer

New to this, but I have a question, my 04 Mountaineer wont start, it has had a new fuel filter, fuel pump, and plugs, what is there left to do...need help asap
 






i have a 2004 ford explorer and it isnt getting any fire or no fuel what could be going on
 






I would check ignition coil, PCM system fuse or anti theft device good luck
 






I have an relay thats under my steering and it been making this buzzinf sound and i brought a new relay as soon as i replaced it with new relay it started like brand new but now its back doing it again buzzing sound with no crank and everything comes on lights.radio.
 






i hooked a battery up to my 91 and the key was off and the engine started cranking over like it was possessed. something is stuck on.
 



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found out the fender solenoid was wired wrong and defective. i wired it right and jumped the two post and it spun right over so i jumped between the battery and the small post and nothing. the starter works fine and the battery is charged that leaves the relay on the fender. that's next on payday. my ign switch fell apart in my hands and i lost my keys so the locking cylinder and the ign switch have both been changed. it is a 91 eddie and i just ordered the electrical book on fleabay for 10 bucks.
 






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