| Author |
Message |
Steve (Steve)
| | Posted on Wednesday, May 16, 2001 - 6:53 pm: | |
Thanks folks I'll try checking the back of the fuse block. I replaced the fuse so I'm starting with a clean part here. It's funny though it is only this 1 fuse (#1) that the problem happens on. I'm back to driving but with the #1 fuse removed and everything is fine.I also noticed as best as I could read the wiring diag. that one of the wires on top of the fuse #1 goes to the coil step down resistor through a relay. Don't know if this is a problem. Well back to the fuse block. Oh buy the way has anyoue tried to replace these 2 fuse blocks with a later type plug in fuse block (bannet type) that is being used by the hot rod guys ? Thanks Steve |
Warren E. Smith (Magoo)
| | Posted on Wednesday, May 16, 2001 - 10:08 am: | |
STEVE, Be sure to let us know what you find. Talk to you later. MAGOO |
Steve Magnusson (91tr)
| | Posted on Wednesday, May 16, 2001 - 9:39 am: | |
Craig/Magoo -- Your points are well taken for a more modern F that has the benefit (if I can use that word) of what might be referred to as a PWA-type approach for the fuses and/or relays and/or connectors -- Steve's '77 GTB pre-dates this technology.
Steve -- I think Erik's on the right track to suspect the fuseholder rivets, but you can also have connection problems due to the rivets on the backside of the fuseblocks where many small metal plates are used to form the power distribution network on the input (top) side of the fuses (I'll place a small wager that there are some of these metal plates in the area of your present "problem"). You might consider soldering some busbar to the fuse input male spade terminals (as low as possible so you can still put the female connector on the male spade) in a way that the busbar pieces act in parallel electrically with the existing small metal plates on the backside of the fuseblock (but I think I should warn you that this is not a super-easy thing because it's difficult to heat such a "large" joint sufficiently without damaging the plastic fuseblock itself).
On the output (bottom) side of the fuses, the interconnection network is handled by putting multiple wires into some of the female spade connector. Probably a less likely area of trouble, but you should inspect the crimping.
Good hunting... |
Craig Dewey (Craigfl)
| | Posted on Wednesday, May 16, 2001 - 6:44 am: | |
I have seen what is commonly called a "cold solder joint" in a lot of electrical equipment -- especially subject to vibration. It gets this terminology because if you look closely at the solder joint, it is similiar to what a connection would look like if the solder wasn't heated enough and it didn't flow properly. Unfortunately, these bad connections are sometimes very difficult to see to the untrained eye. The best way I can describe it without having a picture is to say the solder should flow concave between the wire and the circuit board and be of the same smoothness. If the connection looks at all crystalline or gray in a ring around the wire, you may have this "cold solder joint" condition. In some cases, there will actually be a break in the connection -- a gap in the solder, but this isn't necessarily true. These bad connections exhibit high resistance and can cause the problems you have described. They can be easily repaired by resoldering using a little more of a good flux core solder. Rivets used for electrical connections can be soldered in the same way. If they aren't repaired they can cause burning/fires at the fuseboard. |
Erik Jonsson (Gamester)
| | Posted on Tuesday, May 15, 2001 - 11:00 pm: | |
The fuse holder rivet is most often the culprit. It builds corrosion between the contacts. Best way to solve the problem is to get a decent insulated blade type fuse holder and solder the leads to the contacts on the back side of the fuse block- effectively replacing the crappy style fuse holder. |
Warren E. Smith (Magoo)
| | Posted on Tuesday, May 15, 2001 - 10:20 pm: | |
Very good point James, I also think it might be in that area of the fuse holder.MAGOO |
James H. (Jamesh)
| | Posted on Tuesday, May 15, 2001 - 10:08 pm: | |
I had the same problem on my Porsche. Although the connectors looked good on the fuse holder, it was not making good contact with the fuse and when a load was applied, voltage dropped due to the bad connection or excessive resistance. I also noticed the fuse, which was the lead type seemed a little corroded. A little sanding of the terminals and the fuse fixed the problem. You can also take the fuse holder you have and put two alligator clips on them and clip them on your fuse box terminal and see if the problem still occurs, and if it still does, them maybe its between the terminal and wire. Anyway, good luck. |
Warren E. Smith (Magoo)
| | Posted on Tuesday, May 15, 2001 - 8:45 pm: | |
Just a hunch, I guess you checked the back of the board at that fuse location to be sure that nothing was touching it. MAGOO |
Steve (Steve)
| | Posted on Tuesday, May 15, 2001 - 7:18 pm: | |
Help , I just came up with an electrical bug. Problem is fuse position #1 (brake lights , signal lights , wiper circuit , cooling fan relays , coil bypass relay ). I get 14V at the fuse with engine running and as soon as I step on the brake it goes to a 1/2V and the alternator light comes on. The same thing happens when I move the turn signal either left or right.So I removed the down stream wires and using another fuse holder everything works.All grounds are good , no visible wire damage and all relays work.If I put the wires back on fuse 1 the same problem returns. Also the alternator is putting out 14V on all of the fuses. So I have a work a round by using the Heated Rear Window fuse location and hooked up these wires and the system runs well. Anyone have any hints here? Thanks Steve |
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