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Friday, June 1, 2018 - 07:00
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Backtracking to the fuse panel connectors, we found the wire that was supposed to be feeding the relay and it was dark — it turned out that the innards of that fuse panel had gone open, and now failed to deliver voltage to the motor — the fuse panel was the weak link in the chain, and it had fallen prey to time, chance and obsolescence. But rather than launching a nationwide search for a salvage yard replacement fuse panel for a 2004 Land Rover, and rather than having the guy get a title loan just to buy a new fuse panel, we opted for the workable fix that would strengthen the chain rather than simply replacing the weak link. An overlay isn’t a bad fix in cases like this.

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When we backtracked from the relay to the fuse panel output terminal on this circuit, we found that the fuse panel wasn’t feeding the relay – and so we ran the overlay.

This blower situation isn’t that uncommon and never has been, because blowers pull a heavy load. Back when Ford vans still had glass fuses in the panel under the dash, they would develop a similar problem — they wouldn’t necessarily blow the fuse, but the fan would fail because the solder would melt out of the end of that glass fuse due to heat and resistance within the panel, and Ford had us cut the wires at the panel and install a 30-amp breaker.

In the Land Rover’s case, we got an inline blade fuse holder and a 30-amp fuse, and beginning at the battery junction under the hood, we fed a 12-gauge wire through a loom back through the bulkhead grommet to the relay common terminal, and the blower was resurrected with a solid, lasting repair. I showed the owner where the new blower fuse was and how we had run the overlay through loom along the harness, and he was a happy camper.

The Land Rover’s master cylinder was leaking at the reservoir grommets and we replaced the master cylinder, reservoir and all, to stop the fluid leak — that was a straightforward fix.

A problem two years in the making

The title vehicle for this article is a 2008 Chevy Impala with a 3.9L V6 and 124,654 miles on the odometer that came in on the hook with the report that it was making a horrible racket and couldn’t be driven. What we found was that the #1 spark plug had blown out of its hole. That’s the one under the alternator. Now, this is one of our company cars, and while I didn’t dig into my records when the vehicle first came in, I didn’t remember us ever replacing the spark plugs on this one — not in recent history anyway. It was also sporting a set of replacement wires, which I didn’t remember us replacing.

The 2008 Impala

The problem was that when we tried to install another spark plug in that hole, we found that the plug would tighten down to a certain point and then pop loose again — over and over. Using the Autel inspection scope’s magnified image, we saw threads that didn’t really look that damaged, but the fact remained that a spark plug wouldn’t screw into that hole and tighten up. Looking more closely at the actual spark plug that had blown out of the hole, it appeared that there was some kind of gray material in the threads. What I later realized was that the gray stuff in those threads was probably due to the fact that the spark plug had originally been screwed all the way in, but it hadn’t been properly torqued, and that it had spent a long time bouncing in the threads and slowly screwing itself out of that hole until it was dislodged by compression and combustion.

My initial take on this situation was that no matter how, where or why this happened, we needed to come up with a fix. The alternator had to be removed, and we had to decide what we were going to do about that situation. Another close-up scope shot revealed threads that looked fairly normal, and the threads on the spark plug didn’t look stripped, but I opted (right or wrong) to put a thread insert in that hole for good measure. Of course, when tapping threads in a spark plug hole, it’s wise to first force air into the throttle body and turn the engine over until positive pressure is blowing out the spark plug hole, and that’s what we did. An entire new set of plugs was installed and torqued, and at the time of this writing, the car is still on the road.

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