It has always been interesting to me how a set of jumper cables can look so good and be so dysfunctional when it comes to actually getting a car started. I stopped several years ago to visit a friend of mine. I found him and a teenage boy trying to get a medium-size diesel tractor started with a pair of jumper cables that looked pretty good. They had the pickup truck engine on fast idle with those cables connected, but the tractor starter just wouldn’t spin the compression-fired diesel fast enough to light it off.
My personal jumper cables are a set that I built when I was working down on the Texas Coast. Our company had built a brand-new heliport, and there was a 40-foot piece of leftover electrical cable that was about 3-and-a-half inches thick. Inside the outside sheathing of that cable were four pieces of 00 gauge wire: one with red insulation, one with black, one with white and one with green. My supervisor gave me a 12-foot piece of that leftover cable, and I built it with some 500-amp jumper cable clamps I bought from Spence Battery, the Delco parts supplier I used in Port Arthur, Texas.
Thirty-plus years later, those same cables are in my truck toolbox, and they’re really heavy. And on that crisp autumn day all those years ago when that tractor wouldn’t start, I cheerfully suggested we try my cables. As I dragged them out of my truck toolbox, the teenager snorted at me.
“Them cables ain’t gonna make no difference,” he muttered. The farmer’s son was less skeptical. He and I had a history, you see, and he knew me to be a “can-do” sort of a wrench guy. When we connected my heavy cables and engaged the starter on that Massey Ferguson, it took off like it meant business, spun at normal speed, and rattled to noisy life. It belched a heavy cloud of white fuel smoke from the previous unsuccessful attempts that did nothing but mist copious amounts of diesel fuel into those dark, cool chambers.
Over the years I’ve done a bit of roadside troubleshooting, just to help stranded motorists, you see. Then it turned out that my own F150 threw me under the bus one Saturday morning. And since I’m one of those guys who doesn’t like to work on the lawn mower when it’s time to cut the grass, it was a revolting development to slide into the seat of my pickup and find the battery — a nearly new Motorcraft — so dead that it took my super jumper cables to get the truck started.
Drawing false conclusions
While my own pickup is the title vehicle for this article, I have other stories to tell (as I usually do). We’ve had a busy few weeks at the shop, and when things go the way they should, my guys and gals learn. They also learn when things go south, even when we’re using all our available resources as a hedge against it.
A colleague of mine brought her son’s 2007 Sierra to have it looked at with three concerns. To begin with, her husband had pulled the dipstick on that 5.3L and found it more than 2 quarts low. Well, the oil had fairly recently been changed somewhere, and there wasn’t any noticeable smoke, nor were there any visible leaks, but he’d had to add 2 quarts, so they wanted to know what the deal was.
The second concern was that the wipers wouldn’t work on intermittent, but were fine on low and high. The third concern was that the cruise control was inoperative.
Yanking the dipstick, I found the oil to be overfull to the tune of about a quart. After removing the extra oil, we poked around and found an Identifix search that turned up cases where sludge had the drain-back holes plugged in one head or the other. We decided to yank the valve covers to see what we could see.
It was clean as a whistle under there, so we replaced the cover gaskets and reassembled everything, then drove the truck for about 20 minutes, parked it, and immediately checked the engine oil. It showed full. Maybe the oil change place left it a quart low, and Dad added too much? Rather than dig deeper on that concern, I told the owner to have her son keep a close check on the crankcase oil (he is going to college in a town a couple of hours away) and to keep it serviced regularly.
Next, we tackled the inoperative intermittent wipers. Not having seen this concern before, we scan tooled it, and while our tool said the range of intermittent wiper switch positions should be from 1 to 255, we were only seeing switch output from 1 to 5 — and Identifix spoke volumes about bad switches causing this concern. We got a switch from GM ($29) that didn’t change a doggone thing, not even the 1-to-5 datastream switch range. It would have helped to have another truck for comparison, but we were practically flying blind. I called the Identifix hotline and got a tip: We found that when we unplugged the rain sensor module, the wipers would work just fine on intermittent. Rather than pay to have us replace that $165 module, the customer opted to just leave it unplugged.
Concern No. 3 was the cruise control, and after verifying that it didn’t operate and the datastream told us that brake pedal activation had prevented it the last four times, we noted that the Brake Pedal Position (BPP) input was always “APPLIED.” From what we could tell, that input comes from a pedal position sensor that is separate from the stop light switch (the stop lights worked fine, and that particular PID came and went with pedal activation).
We got a BPP switch in short order and popped it on there, but to no avail. When I checked the voltage at the BPP switch, it was come-and-go for some reason, which seemed to be the root of our concern. But she had to take the truck and return it to her son cruiseless, so we got a two-out-of-three on that one.
Cause and effect
Gene, one of our maintenance men, always has his eyes and ears open for students with car trouble, and he saw one of our welding students beside the road a mile or so away from the college with the hood up on his 2004 Explorer. Gene dragged the crippled ride back to my shop, where I made a work order and had the driver sign it while the students puttered around with it outside one of the service bays.
That 4.0L SOHC would spin over, but there was no fire in the holes. We had fuel pressure at key on, but neither spark nor injection, even though the injectors and the coils were powered up. There was no security light flashing, and a scan of the datastream failed to produce anything except a big fat zero on the Engine RPM line. So we shoved it into the shop, and I had one of the students roll under there on a creeper to have a look at the crank sensor — which, it turns out, had been destroyed because the harmonic balancer came apart and the pulley belt guide had machined that plastic sensor down to its copper guts.
The pulley part of the balancer had come unbonded from the rubber insulator, and had slid back toward the timing cover — enough so that the serpentine belt had walked off the balancer and was riding on an inch of exposed balancer rubber. He had ignored the belt squeal to his own peril.
Well, the ’04 Explorer owner didn’t want to spend the $110 on the balancer I had already ordered from the parts store (which was slated to show up later that same day), so he paid the basic charge and dragged the vehicle to his uncle’s house to get a used part put on it.
Meanwhile, Olivia’s 2008 Explorer came wheeling in with a squealing belt and exactly the same kind of balancer failure, except this one didn’t totally destroy the crank sensor. This particular 2008 Explorer is charmed, because usually no matter what happens, it seems we’re always able to work miracles getting parts to get Olivia out of there in a single day.
This time was no different: Because the other balancer was en route and the first Explorer pilot didn’t want it, we used that part to get hers done quick, replacing the belt for good measure.
Two weeks later, the 2004 Explorer driver showed up wanting a full set of used tires mounted on some rims he was pulling behind him on a trailer. We’re a college automotive program with a basic charge and no labor, yet he wanted to know how much it was going to cost and wanted to know if we could get the job done before he left at 10 that morning. I looked at my watch, shook my head, and sent him packing. Some people can be ridiculously demanding, and this guy was more trouble than he was worth in one day.
Two no-starts
Regular readers might remember the yellow 2005 Crossfire we fixed for a no-crank concern about a year ago. Well, this time it was a quitter. It had never failed to spin over since the other repair. She hadn’t driven it for a while, because now it would stall and not restart while driving. The battery was dead the morning she decided to bring it in for the stall-no-start issue. It’d sit for a half an hour and go again, which is one of the most common symptoms of quits-while-driving issues.
As a matter of fact, when she was on the way to us that morning, it quit close enough to the shop that we could see it from our service lot. Our hale and hearty maintenance guy drove up there with one of my guys, but it started right up and my guy drove it back to the shop.
Caught in the Crossfire again — this time for a quits-while-driving. The P0335 code led us to a crank sensor that was opening up hot, and then we found a bad alternator. We also replaced the $180 hood lift support at the customer’s request, which cost more than the $169 alternator.
We weren’t able to talk to the enhanced side of the Crossfire PCM, but the OBDII room gave us a crank sensor code. We scoped the crank sensor to find that it would flatline and then the engine would die. We removed the sensor, ohmed it and got 1,050 ohms, then used a heat gun to make it open up right there on the bench. That was easy to do, so it got a new one. Were we done? Not exactly — the alternator was whirring, stinking and barely putting out, so we had to put an alternator on it, too.
No-start No. 2 was a 2002 Saturn that came in behind a pickup. This one is a serious bomb. If we wanted to upsell this one, we could work on it for weeks, but this guy won’t buy anything he doesn’t have to. One way or another, we had spark and fuel injection, but when I had one of the students connect a fuel pressure gauge, he called me over to see what I thought of the stuff that wet his fingers when he was fiddling around at the Shrader. It felt really cold and smelled like pure alcohol, and when we transferred some to a graduated container and did the test, it was 20 percent alky — but I know the fuel rail was full of a higher alcohol concentration than that.
We engaged the fuel pump to run steadily by jumping the relay, thus we pumped heavier-than-gas cloudy looking cocktail into a 5-gallon plastic container until the cloudiness cleared up, then we managed to spin the engine to let decent gas push the alcohol on through the injectors and start the car on gas. The guy who brought it in was mystified as to how the alcohol got in there, but I suggested that his sister might have pumped some E85 into the tank. One way or another, that one was a rich example of why fuel sample testing is important: No parts bought.
Closure on my own ride
I drive my F150 on weekends around town and my 2007 Taurus to work for economy. Initially when the battery died, I checked for lights that were left on, and even disconnected the instrument cluster for a week (a known concern on some of these), only to find the battery dead again the following week.
One Friday afternoon, I gave it some priority and found the problem. With my meter connected between the positive post and its corresponding terminal to read amps, I found 0.200 mA leaving the battery even when everything was supposed to be off. More than 0.050 mA is too much. No wonder the battery was dead after a week!
The only fuse panel this base F150 has is behind the right lower kick panel, and I went to work down there, yanking fuses while watching my meter. When I got fuse 21 yanked out of there, the meter registered zero. That fuse provides “Keep Alive” power to the instrument cluster, which I knew wasn’t the problem.
I bought a brand-new $250 central junction box. I’ve seen these develop internal shorts and opens ever since 1997, when Ford started using those internally laminated boxes. After I replaced the CJB, I’ve had no dead-battery problems at all.
Conclusions
While it’s important to know how to replace parts, it’s even more important that we learn (and teach) surgical troubleshooting skills and critical thinking so the guys in the trenches can find out what’s wrong and don’t replace parts unnecessarily. We can sometimes get in too much of a hurry and throw parts that aren’t needed. Usually a bit of cause-and-effect reasoning and skillful information gathering and sorting can save us time and the customer money.
Too many mechanics haven’t developed those skills and that kind of thinking. While I don’t have all the answers, the writing and hands-on teaching I do represent my attempts to change that trend.
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