Number four son's 240 wouldn’t start earlier this week. The car turned over fine. Like all good brickster's, I checked the fuses before doing anything substantial. None of the conductors were melted. I then sprayed some starting fluid into the throttle body hose. The car caught, but wouldn't keep running. Disconnecting the AMM didn't change anything. The spark plugs were dry as a bone.

I was now convinced that the problem was probable the main fuel pump. On a whim, I decided I would rotate the fuses before attempting anything more drastic. While working my down the stack, I notice that one seemed ever-so-slightly misaligned. It just happened to be the fuel pump fuse. I pulled it, and noticed that while the conductor was perfect, the plastic fuse body was slightly melted. The plastic ran down via capillary action between the conductor and holder terminals. Apparently, the fuse was forced very slightly out of the holder during an earlier anti-corrosion rotation. The reduced contact area increased the electrical resistance, which generated enough heat to resistance was enough to soften the plastic body.

The moral of the story is to look at more than the fuse conductor when checking fuses. If a fuse seems slightly misaligned, even if it rotates and as a perfect conductor, pull, inspect, and clean it before moving on to a more time-consuming diagnostic step.

Every five years or so, it's worth chucking all of the old fuses, hosing down the fuse box with contact cleaner, wire brush shiny and clean, then replace with all new fuses, each with a dab of dielectric grease on each end.

Clean fuses make life really easy. :-)

-Ryan
--

Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars, GT Braces
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars

I have had good luck with IPD's ceramic fuses for 240s. They seem to be very well made, and last a long time.

Ryan - You set a standard for preventative maintenance I can only dream about! Glen

It was an '89 244. Fues 6 or something like that. GP

Make that a '91 244. As Art and Bruce pointed out, fuse 6 in '89s does nothing. I was just checking to see if everybody was paying attention ;-)

Not to rain on your findings, but your 89 240 will run around town just peachy without any fuses in the panel inside, as long as the fuel tank is fairly full. Of course you might get a ticket for no brake lights or turn signals.

#6 isn't even in use.

Haven't seen you around in a while... glad you're still a brickster!
--
Art Benstein near Baltimore

Never test the depth of the water with both feet.

I would also add to use only ceramic fuses, they don't melt. Dan

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Dan - Now that's an excellent suggestion. I've gotten in the habit of taking fuses from my parts cars, buffing the ends with mild steel wool, and reusing them without paying much attention to the body. Probably false economy. The fuel red fuel pump fuse carries a lot of current (25 A rating?), so a marginal connection made it prone for melting. The thing that really amazed me was how completely and smoothly the plastic flowed over the tip.

"The fuel red fuel pump fuse carries a lot of current (25 A rating?), so a marginal connection made it prone for melting."

Hi Glen,

I'm still in the dark about exactly what fuse you fixed. As Art Benstein noted above, the "red fuel pump fuse" (16 amp) in the '89 fuse panel is not wired to anything (on U.S. 240s), and the car will run with it completely removed.

In effect it's just a spare fuse until the '91 model, where it becomes active and replaces the underhood 25 Amp blade fuse.


--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Speaking of this issue...my 242 is running a 16 a fuse for the fuel pump rather than a 25. Does it make a difference? Obviously my car is starting and running and not shutting off, so if it does make a difference, wherein does it lie?

Bruce,

We have a brick of just about every vintage. This one happens to be a '91. I drive the '89...

Disconnect the battery and remove the fuses. Then using a brass brush clean the contacts on the fuse box, slightly squeeze the contacts of each fuse to make sure it holds the fuse firmly. The fuel pumps draw a good bit of current stay away from plastic keep it clean with good contact. Dan

Several years ago while on a family trip, our '83 245 GLT suddenly stopped in the evening along I95 just south of DC. I inspected all fuses, rotated them, cleaned fuse contacts and still couldn't get it re-started. Had it towed to a Volvo-oriented shop. The next morning the car was ready to go. Just a fuse (fuel pump I believe), a fuse with glass and metal end caps. Seemed visual inspection wouldn't have found the failure point. The fuse failed up under one of the metal end caps, out of view. I should have been more persistent and put critical thought into the car failure and then I would have replaced possible suspect fuses. But, they all looked good to me.

Mike

Yes - a tester is a good thing to have and use.
Would have found your bad fuse.

A multitester would do this job, or a simple continuity tester would also do it.

If you aren't familiar with these, or if electrical theory gave you nightmares, start by recognizing that these two tools aren't up there with rocket science. If you can navigate this message board you can learn to use those testers. Far better than swapping around fuses or sometimes bulbs or flashlight batteries in an attempt to figure out which one is bad.
--
Sven: '89 245 NA, 951 ECU, expanded air dam, forward belly pan reaches oem belly pan, airbox heater upgraded, E-fan, 205/65-15 at 50 psi, IPD sways, no a/c-p/s belt, E-Codes, amber front corner reflectors, aero front face, quad horns, tach, small clock.