Fuse Box Replacement? Corroded wires
10-13-2003, 01:44 AM
#1
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Fuse Box Replacement? Corroded wires
Have any Rennlister's ever had trouble starting their 911 related to corroded wires in the fuse box? Some of the wires seem to be burned. I want to replace the fuse box & wires in my 79SC just to be on the safe side. Has anyone had any experience replacing or refurbishing the fuse box?
10-13-2003, 03:28 PM
#2
Burning Brakes
Had an '86, 930 where the fuse box cracked though behind the petrol pump fuse - apparantly this form of fuse box failure is not unusual (so I was told) - new box about £50 ($65??). and not too difficult - just mark up all the wires as you undo them.
PJC
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10-13-2003, 10:23 PM
#3
Drifting
The fuel pump fuse failed on my 78 SC Targa at one of the most embarrassing times EVER.
When I loaded onto the ferry from downtown Seattle to Vashon Island the crew went out of their way to place me front and center, first for departure on arrival at the far side.
Would you believe the car would NOT start on arrival?
Crew helped push it back and forth, out of the way of different lanes as the ferry was unloaded. Then brought a jitney aboard for tow. Someone, of course, yelled "get a horse" as the jitney pulled me off and into the far corner of the parking lot.
The fuse had not failed, the fuse holder, and the wire end, had gotten so hot, time and time again, that it's springiness was gone.
Installed a bypass fuse holder, and off we go to the next adventure!
When I loaded onto the ferry from downtown Seattle to Vashon Island the crew went out of their way to place me front and center, first for departure on arrival at the far side.
Would you believe the car would NOT start on arrival?
Crew helped push it back and forth, out of the way of different lanes as the ferry was unloaded. Then brought a jitney aboard for tow. Someone, of course, yelled "get a horse" as the jitney pulled me off and into the far corner of the parking lot.
The fuse had not failed, the fuse holder, and the wire end, had gotten so hot, time and time again, that it's springiness was gone.
Installed a bypass fuse holder, and off we go to the next adventure!
10-13-2003, 11:52 PM
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Yes, the fuse blocks (and the fuses themselves) in our old cars, are an abomination! They are prone to attack from the environment, and lack electrical integrity once the flimsy brass contacts degrade.
The fuel pump fuse is particularly prone to give trouble. The fuel pump is a fairly high-current load. When the fuse block contacts (and wire terminals) become too resistive, the brass fittings over-heat, and burn up. The pump stops, and you are parked by the roadside!
Other than a total re-design of the block, all you can really do is re&re the whole damn thing; cleaning all the terminals and contacts, reterminating any burnt wire ends, replacing corroded fuses, and dabbing a little bit of copper or graphite grease on all current-handling interfaces.
The fuses and the block are one of the worst parts in the whole car. They can cause you to be stranded, or worse...cause your car to burn to the ground!
The fuel pump fuse is particularly prone to give trouble. The fuel pump is a fairly high-current load. When the fuse block contacts (and wire terminals) become too resistive, the brass fittings over-heat, and burn up. The pump stops, and you are parked by the roadside!
Other than a total re-design of the block, all you can really do is re&re the whole damn thing; cleaning all the terminals and contacts, reterminating any burnt wire ends, replacing corroded fuses, and dabbing a little bit of copper or graphite grease on all current-handling interfaces.
The fuses and the block are one of the worst parts in the whole car. They can cause you to be stranded, or worse...cause your car to burn to the ground!
10-14-2003, 09:55 AM
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Thanks pjc, wwest, and dial, that is exactly the response I was looking for. I am pretty confident that my start problem is directly linked to the rusted wires going into the fuel pump fuse in the fuse box. I am getting the old fuses and wires replaced this week. The fuse box problem left me stranded twice, it's annoying not knowing whether my car is going to start or leave me stuck wherever I go.
10-14-2003, 10:17 AM
#6
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I had the failure as well, and replaced as wwest did. I believe the location of the fuse panel and the battery in this basically sealed compartment contributes to the problem. Battery over-charges, off-gases, accelerates corrosion in the fuse block, high resistance, excess attention to the area with repeated cleaning of the contacts weakens the spring tenstion... Install new fuse block and re-tin the connectors. Should work well for another 15 years. In most other cars this is not a problem because the battery and fuse block are not sealed-up together in a small air tight compartment. You will find out that when your electric windows don't work, neither do your brake lights or speedometer.
Last edited by Alan Herod; 10-14-2003 at 01:08 PM.
10-14-2003, 12:58 PM
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I've been having some fust trouble too, it's pretty easy to check the fuses with a voltmeter. If your fuse box is in the front right by the battery like mine is, you can set the voltmeter to 20 volts, ground it to the battery, and then touch the other end to the different fuses to see if their getting power. I have been pleased to find that my fuse box is fine, I just have some bad fuses.
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10-14-2003, 01:15 PM
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The old style 'euro' fuses are crap!
The exposed element is a stupid design (possible fire danger). And the bare end-caps are vulnerable to corrosion. That's why I like to use a bit of copper grease on the contacts.
I knew a fellow who built a custom fuse panel, using modern, sealed fuses and sockets.
It took him a long time to build, and install without butchering the OE harness. Great upgrade, IMO.
The exposed element is a stupid design (possible fire danger). And the bare end-caps are vulnerable to corrosion. That's why I like to use a bit of copper grease on the contacts.
I knew a fellow who built a custom fuse panel, using modern, sealed fuses and sockets.
It took him a long time to build, and install without butchering the OE harness. Great upgrade, IMO.
10-16-2003, 07:00 PM
#9
Burning Brakes
There's a guy on the Pelican board that just installed a gorgeous fuse box. It's OEM in look, but uses modern fuses. Fits exactly where the old box fit. I don't know if it's an off-the-shelf item, or if he fabricated it. Regardless, it looks great!
10-20-2003, 10:55 AM
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Got my 911 back this Saturday from getting the rusted fuse box wires refurbished. I thought my problem was solved, I drove it the whole day and the SC started up strong every time, until Saturday night. I was heading back from Virginia around 12:00am, and was about to merge onto I270, when I went over a nasty pothole which caused me lose power again(see " my 911 has an attitude problem" post). Luckily, I had a jumper wire that I connected to the screw on a fuse, and the other end into where my fuel pump relay goes. After doing this, my SC started up like nothing happened, I removed the jumper wires, put the fuel pump relay back in, tried to start her up, but she wouldn't fire up. So my SC starts every time I use the jumper wire, but struggles to turn over without it. Now I am thinking the problem could be related to the fuel pump relay, or the ground wires. Does anyone have any other suggestions as to what might be causing this failure whenever I hit a bump? Alan, what county is Leonardtown in, thats a nice looking GP white 911SC you got there.
Last edited by Par911; 10-20-2003 at 03:34 PM.
10-23-2003, 10:47 AM
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Does anyone know what the difference is between the flat fuses and regular OEM fuses. I am interested in converting my current OEM fuses to flat ones, because I heard that they are better. Does anyone know why they would be better than the OEM fuses? Thanks
11-06-2003, 05:22 PM
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Two issues:
- on the original fuse block..check the rivets that hold the fuse blades in place. They come loose over time and you may want to remove and solder the rivet points. Also, look for the incoming bus-bar that bridges various incoming points. You may want to "duplicate" the bridge with a parallel wire set.
Newer ATO style (USA) fuses have larger contact areas, are more compact, can be probed from the rear with a VOM tester...don't corrode because they'er buried. etc etc. The "suppository" Euro fuses just plain suck and are an embarassment for our cars !
---Wil Ferch
- on the original fuse block..check the rivets that hold the fuse blades in place. They come loose over time and you may want to remove and solder the rivet points. Also, look for the incoming bus-bar that bridges various incoming points. You may want to "duplicate" the bridge with a parallel wire set.
Newer ATO style (USA) fuses have larger contact areas, are more compact, can be probed from the rear with a VOM tester...don't corrode because they'er buried. etc etc. The "suppository" Euro fuses just plain suck and are an embarassment for our cars !
---Wil Ferch
11-07-2003, 09:24 AM
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Thanks Wil, I will check the rivets of the fuse blades, I am currently putting in a new fuse block because the old one was cracked. Do you know where I can get the ATO (USA) style fuses? Are they available at the local auto store, or will I need to special order them? Thanks for the help.
11-07-2003, 12:23 PM
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Originally posted by Alan Herod
I had the failure as well, and replaced as wwest did. I believe the location of the fuse panel and the battery in this basically sealed compartment contributes to the problem. Battery over-charges, off-gases, accelerates corrosion in the fuse block, high resistance, excess attention to the area with repeated cleaning of the contacts weakens the spring tenstion... Install new fuse block and re-tin the connectors. Should work well for another 15 years. In most other cars this is not a problem because the battery and fuse block are not sealed-up together in a small air tight compartment. You will find out that when your electric windows don't work, neither do your brake lights or speedometer.
I had the failure as well, and replaced as wwest did. I believe the location of the fuse panel and the battery in this basically sealed compartment contributes to the problem. Battery over-charges, off-gases, accelerates corrosion in the fuse block, high resistance, excess attention to the area with repeated cleaning of the contacts weakens the spring tenstion... Install new fuse block and re-tin the connectors. Should work well for another 15 years. In most other cars this is not a problem because the battery and fuse block are not sealed-up together in a small air tight compartment. You will find out that when your electric windows don't work, neither do your brake lights or speedometer.
