Tuesday, January 23, 2007

TULZ - Part Eleven

TULZ – Part Eleven

CLICK!

You jump in, pump the accelerator pedal a few times, even though you know it sez to only press it down once. (More is better, right?) You turn the key and… CLICK.

The moment of Truth has arrived.

If you're late for class or work or whatever, when you hear the Big CLICK! the wiser course is to IMMEDIATELY fall back on your alternative means of transportation. And if you ain't got one perhaps you should think about that.

Your second alternative is to push-start it. But there's more involved here than just starting the engine. First, you gotta know HOW to push- start it. Second, you gotta be fairly sure the problem is not a dead battery. Did the warning lights come on? That means you got juice but it doesn't tell you how much. Got headlights? Then the battery is probably okay and you're Go for the Push-Start Follies. But before you start pushing, think. Wherez your tools? The odds are, it's not going to start after you get to wherever it is you're going, either. The Big Click is fair evidence you've got repairs ahead of you. If the vehicle is already home with your tools, hoof it.

A push-start may get you to where you're going. Or it may not. What if it dies in traffic? And if it doesn't you're still going to have to push it again to get home so that means you need to park it someplace where push- starting is practical. Can you be sure of finding such a place?

Remember the Unholy Trinity of maintenance? You need the tools, the skills and a place to work. If you KNOW your ride needs fixen, taking it AWAY from your tools with the notion of getting around to the work later is stacking the odds against you.

So you're at work or school or whatever and you gotta get home because that's where all your tulz are, and the battery is up and the thing was running okay the last time it ran and you're parked in a place that will allow you to do a push-start, go ahead. But you need to know HOW to do a push-start.

PUSH-START, HOW-TO

Brake is OFF. Lean into it, get it rolling, jump in, turning on the key and putting it into FIRST GEAR at the same time as you pop the clutch. That is, let the clutch out SUDDENLY then push it right back in. When multiplied by the gearing, a walking pace is fast enough to cause the engine to rotate one or more full revolutions, which means at least TWO cylinders will have a chance to fire. If the engine is in a good state of tune, that's all it takes.

Once it fires, baby it; keep the thing running until it warms up and idles sweet, because you don't want it dying on you in traffic.

THINK ABOUT IT

Odds are, if you've never push-started your vehicle, it won't start the first time you try it. Push-starting by yourself calls for a fair degree of strength and coordination. The lesson here is pretty simple: The best time to learn how to do a push-start when you DON'T need it; when your ride is running. So go PRACTICE. Find yourself an empty parking lot and TEACH YOURSELF how to get your vehicle running without using the starter. Back in Part Eight I suggested you teach yourself how to drive without using the clutch. Learning how to start your engine without using the starter falls into the same category of Get Home skills.

When push-starting your ride here's some tricks that will help. Pump your tires up. That will make it roll a lot easier. Get your engine in perfect tune. Set the static firing point closer to TDC or even a couple of degrees AFTER top dead center. You can't drive it with that setting but it will start and idle a lot easier. And if you have a dynamic timing light it's a simple matter to reset the timing once you get it running. Don't leave the key on too long. You need the choke for it to start and the choke is electric. If you leave the key on and the choke will eventually move to the off position even if the engine isn't running.

FIXING THE BIG CLICK

The CLICK itself is your main clue. It tells you power is getting to the solenoid. At that point the decision tree branches. Either the contact bar in the solenoid is worn or corroded or otherwise damaged so that it is not capable of doing its job (which is to connect the battery to the starter) or the solenoid isn't getting enough power to press the contact bar closed. There are some variations on this theme but they have different signatures. For example, CLICK! Whirrrr… means the pinion isn't engaging the flywheel whereas CLICK! Groannn… means the pinion is binding or the engine is seized or one of half a dozen other things.

The above should make it pretty clear that diagnosis is based on a complete understanding of how the system operates. It should also serve to illustrate that diagnosis reflects a decision tree.

If you'll examine the workshop manual for any modern vehicle you find it is largely devoted to depictions of the diagnostic decision tree in schematic format. You'll also see that virtually no space is given to telling you HOW to do the mechanical aspects of the repair. Instead, they tell you how to do the various diagnostic tests. When it comes down to R&R, the removal & repair (or replacement) of the component, the manuals assume you know how. Indeed, the WRENCHING is the easy part. The hard part is knowing what to wrench and you can only learn that by starting with the basics and working your way up, which is why I suggested you begin with a lawnmower engine. But that's too much trouble, right? Especially when you can jump on the Internet and take a poll as to why your wheel just fell off. Unfortunately mediocrity can never rise above itself. A majority of unskilled mechanics will always give you an unskilled answer. (For every two hundred people who read this, only one will understand. So be it. Right now we're trying to get your bug started so let's get on with it :-)

The Big Click sez the problem is either in the solenoid or that insufficient power is getting to the solenoid. We can test for the latter by using a jumper cable from the battery lead to the spade lug on the solenoid, thereby eliminating about twenty feet of wiring and the possibility of a bad ignition switch. But let me tell you right now this is a very dangerous test. It should only be done when the vehicle is supported on jackstands. Why? Because the engine is liable to start. And if it does, it's liable to run over your ass.

So leave the key OFF. That will prevent power from going to the ignition circuit. Better yet, pull the HV lead out of the coil. Then do the test. If you don't know which lead goes to the battery, use your manual to figure it out. And if your solenoid is the later model with the two spade lugs, figure out which one goes to the ignition switch.

Back in Part Four I suggested you make up some test leads, including some with spade-lug connectors. This is a good time to use one. Detach the starter-switch lead from the solenoid and replace it with a jumper having a female spade-lug connector on one end and an alligator clip on the other. To complete the circuit, TOUCH (do NOT clip) the alligator clip to the battery cable connector. Do NOT touch the copper stud nor the nut. The arc is enough to damage the threads of the stud and will bugger the nut when you try to remove it.

IF the jumper test causes the starter to engage and to crank the engine then the problem is in the wiring or the ignition switch, with the higher probability for the latter. There is an interesting history to this particular problem.

The starter solenoid needs about ten amperes to pull-in but only about an amp to hold-in. This is not uncommon and is a characteristic of solenoids. Your ignition coil is also a solenoid-wound inductor and it too has a high inrush current. Unfortunately, the VW ignition switch is only good for about eight amps (!) whereas the inrush current when you try to start the engine EXCEEDS the safe current carrying capacity of the switch meaning it's going to go bad, sooner or later. Bosch recognized this and came up with a simple fix, a pilot relay that mounts on the solenoid. The Bosch part number is WR-1 and the whole thing only costs a few bucks.

What the pilot relay does is to use about a quarter of an amp to connect the solenoid directly to the battery, eliminating the need to run that momentary jolt of ten amps through the ignition switch. Well designed and easy to install, the pilot relay will eliminate a host of starter problems on Volkswagens, especially on the Transporter which has longer wiring runs and therefore more loses.

Unfortunately, 'way back when, Muir and other experts told all the kiddies to use a Ford contactor as a pilot relay. The joke here is that the Ford contactor pulls almost as much current as the Bosch solenoid!

A pilot relay is a good idea. Bosch dealers sell them as do a few VW dealers. Berg recently rediscovered them after years of selling the Ford contactor. Or you can make your own. A horn or headlight relay works fine and the installation procedure has been posted to the Internet on numerous occasions. Check the various archives.

If the jumper test didn't help then you've narrowed the problem down to the solenoid. Fortunately, the fix is pretty simple. Start by removing the battery from the vehicle, then remove the starter, dismantle the solenoid and file the contactor and contacts smooth. You'll need to unsolder a couple of leads to dismantle the solenoid. Use a bit of Solder Wick to get the solder out of the holes. When you reassemble the solenoid be VERY SURE to use RTV or other WATERPROOF sealant.

The 'Idiot' book covers starter problems rather well and certainly justifies your study. But DON'T use that ohsokewl trick of shorting the terminals with a screwdriver. Yeah, it works. It also damages the terminals as well as the screwdriver.

Next time you go to replace the battery cable you discover the threads on the solenoid are buggered all to hell; the nut won't come off (or it shears the copper stud). You can't get a die onto them, even if you had the proper die [which you don't] and you can't remove the old cable. You have to remove the entire starter and chase the damaged threads with a sixty-degree vee-file [see a set of Swiss pattern-maker's files]. That is, assuming the threads aren't buggered too badly. But if you've done that ohsokewl Idiot Trick more than a couple of times, forget; you'll have to buy a new solenoid. Swell idea, eh?

In the same vein, DON'T go pounding on the solenoid with a hammer. Yeah, this also works. And damages the solenoid in the process.

The usual reason for a solenoid to stick is due to rust on the plunger. The proper fix is to remove the starter, dismantle the solenoid and DEAL WITH THE RUST. If you just pound on the thing you might jar the plunger loose… and you might not. The odds are about 50-50. And of course, you'll only hear about the successful tries.

A basic tenet of a good mechanic is to do no greater harm. The 'Idiot' book is larded with procedures that damage the vehicle. Once you've buggered an axle nut or starter stud don't expect to find a mechanic to save your bacon. Competent mechanics usually refuse to work on a vehicle that shows obvious signs of abuse since they can be held liable for future failures even if they didn't work on that particular component. It isn't fair and it certainly isn't logical but when our nation's President, who happens to be an attorney, doesn't know the difference between a blowjob and a hand shake, it's easy to see how such bullshit comes about. Idiot book indeed. (Ed.Note [2006]: The current Prez is an even dimmer bulb :-) Indeed, we Americans have the best government money can buy.)

THE BIG NO-CLICK

You jump in your ride, turn the key and… You turn the key and… eh? Nothing. Well, mebbe something. Mebbe the indicator lights came on. Or mebbe not.

The Big Click is pretty easy to diagnose but the Big No-Click can be a worse headache because of the lack of data. No click means no juice getting to the solenoid… mebbe.

No click and no indicator lights is pretty good evidence you're not getting any juice. The first thing you need to find out is if you got any juice to get. Try your headlights. Bright? Normal? Then you can probably rule out the battery. But no lights doesn't mean the opposite, it simply means no juice is getting to the lights; the battery could be just fine. So you start from Ground Zero and begin climbing the diagnostic decision tree.

Ground Zero is your battery and cables. And one of those cables is the ground strap on the nose of the tranny.

The Main Electrical Buss runs from the starter to the battery. That's why it's there; the battery's primary purpose is to start the engine. All else, from your ignition system and electric lights to your bitchin' sound system came along later. (Early cars used magnetos and were started with a crank. If you wanted to drive at night there were acetylene lamps, some of which were brighter than any headlight you've ever seen. And if you wanted a bitchin' sound system you hired the band :-) When it comes to the battery and cables there really isn't much to diagnose. The terminals must be clean, tight and free of corrosion. The cable must be undamaged with no sign of corrosion at the fittings. The grommets isolating the cable from the chassis must be in good condition.

If your electrical system fails this very basic inspection, deal with it! Neutralize any rust you find and put down an anti-corrosion pad under the battery. Clean the terminals down to bright metal, put anti-corrosion pads under the terminals and install new cables with suitably fitted terminals. Once everything is tight, give them a spritz of anti-corrosion spray (I use that purple stuff). Where the ground lead is bolted to the chassis, eliminate any rust or corrosion then put a light coating of copper-based anti-sieze where the fitting will be bolted down. Thereafter your only maintenance is periodic inspection and cleaning.

The Distribution Buss is a heavy red wire that runs from the battery cable-solenoid junction to the fuse block via the headlight switch. The ignition, starter solenoid and indicator lamps are not fused and pick their power directly from the headlight switch via the ignition switch.

You can track the path of the circuits using your timing light. In most cases of the Big No-Click the fault will be in the headlight switch or the ignition switch and the repair is to replace the switch. But in some cases you can track the active circuit all the way back to the solenoid only to discover it is bad. (This is where Muir brings out his hammers. Resist the impulse.)

Now you got a major problem because you can't repair the winding of a Bosch solenoid, you've got to replace it. Unfortunately, a new solenoid, assuming you can find one, will cost over a hundred dollars. So you start hitting the junkies, trying to find a replacement starter which, by custom, comes with the solenoid attached. (In the mid-1950's I push-started my bug for a YEAR because I couldn't afford a replacement starter only to discover the problem was the solenoid. Live & lurn :-)

The electrical routing above is valid for about eighteen million Volkswagens. I don't have a lot of experience with later models but the same principles of diagnosis will apply. See your manual for your particular vehicle's wiring diagram, which you should study until you can draw it from memory. And if that sounds a bit much, it's not. There are common elements to all automotive electrical systems. Once you've learned one it will serve as the foundation on which to learn others

PREVENTION vs CURE

Your electrical system is one of the easiest parts of the vehicle to maintain. It has very few moving parts and its operation is governed by only a few basic principles. Once you've mastered them the system has no secrets.

Certain types of electrical system problems having to do with the AGE of your ride are becoming more common. They involve the grounding circuit. Using the steel body of the vehicle as one side of the electrical circuit is common automotive practice and typically causes no problems. But after a quarter-century or so the dissimilar metal junction between the electrical connector and the steel body can create a barrier having a high resistance. This is especially critical with regard to your headlights and tail lights.

Owners of vehicles having a six-volt electrical system often convert to twelve-volts because their headlights have dimmed down to a yellow glow. It comes as quite a surprise to find their new 12v system doesn't do any better. The truth is, a six-volt headlight is just as bright as a 12v headlight. The problem is not a lack of voltage but an excess of resistance, typically in the grounding circuit. Repair usually requires no more than dismantling and cleaning.

Add this to your warbag: Never pound on a battery's terminals. You'll break the seal between the terminal and the case and the electrolyte will wick through the crack. Always use acid neutralizing pads, the big kind for under the battery and the small circular jobbies under the battery terminals. NEVER slosh your battery with a mixture of water & baking soda. It will get inside the battery (see above; cracks worth in both directions) and ruin the end cells. If your cables are corroded, replace them. When replacing a cable ream the terminal to a perfect fit on the battery posts. Add the little tool for this job to your electrical kit. Batteries are heavy and inherently dangerous. Get yourself a battery carrier and use it. Keep it in your electrical kit. Ditto for the little can of anti-corrosion spray. Make it a habit to REMOVE THE BATTERY any time you work on the vehicle. Not only does this prevent accidents, it gives you a chance to inspect the battery. When the battery is out of the vehicle, put a board or piece of cardboard across it; you don't want anything to short across the posts. (I know a kid who lost a finger when his wedding ring completed the circuit across a fully charged battery.)

-Bob Hoover
-22 May 2K
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