Spitfire Spitfire[Lucas]wiring problem FOUND!

[myspitfire]

Hi thought i'd pass this on to those trying to trace lighting problems.My specific problem is/WAS the parking/marker lights would work sporatically(come on/go off)thru a process of elimination i wound up checking the fuse block & where the 3 fuses snapped in,my problem was the center fuse wasn't making good contact with the tension connectors.(this fuse operates the dash,parking/marker lights)i wrapped the metal end(s)of this fuse with aluminum foil and walla! problem gone.It looks as though a new fuse block is in the works.Maybe this can be added to the bunches of quandrys concerning Lucas wiring,maybe help someone else....KensWhitelightning(myspitfire)I can now go on with my nightime /ubbthreads/images/graemlins/driving.gif /ubbthreads/images/graemlins/savewave.gif

 

[RomanH]

Ken,
Good piece of detective work! Congratulations.
If I were you though I would get rid of the aluminum foil, it may cause more problems than it's fixing. What you can do now that you found the culprit is to clean the contacts in the fuse box with some light sand paper. After everything is clean you can use a pair of needle nose pliers to bend the two opposing tabs of the fuse holder closer together. This will ensure that there is enough pressure on the fuse terminal so as to have consistent contact and eliminate your lighting problem.

 

[myspitfire]

Thanks;Well i'm one of those individuals,when i see a problem especially with my significant other:-o,Its one of those never give up the ship things...In response the fuse box suggestion was something i did try,pinching the tabs,& sanding the contacts but the center fuse clips are a little loose when i tried to pinch them together,i didn't want to put to much pinch as something may give way inside the block......One question can the fuse block be removed easily.I looked up under the dash at the fuse block mounting & it looks like their are black clips holding the block in place for removal,if thats true does it unhook to the engine compartment or to the inside under the dash in case i eventually need to remove it?..Keep the suggestions coming,so far i get better responses here than anywhere.
Ken 1500 80 Spitfire.....my second in command for attention. /ubbthreads/images/graemlins/savewave.gif

 

[Andrew Mace]

One not-so-minor problem with changing the fuse box is that so much of the wiring harness passes THROUGH it. That means lots of disconnecting of pretty much everything forward of the bulkhead. /ubbthreads/images/graemlins/eek.gif

 

[Guest]

I had a similar problem with side lights, and found they were not grounding to the body well. I removed them, cleaned up the back side of the fenders where they mount, and then cleaned the hardware. I had already done the fuse holder and it helped, but cleaning up all the grounds stopped all flickering.

 

[myspitfire]

Friend(s)With all your great suggestions the problem is now finally solved after SSooo so much tracking/tracing,It did end up at the fuse block & one suggestion was to remove my temporary fix with aluminum foil at the clip contact & sand with the Dremel on the contacts,Which did the trick.At this point my removal of the fuse block isn't necessary Whew!..Its amazing how one can get bent out shape repairing things on it fearing the worst & finding an easy fundamental repair.After owning these cars its most always been the simple common sense approches that gives you that great DIY feeling.Its the bonding i guess...Cheers
PS;I did end up fixing alot of doubtful grounds & replacing 25 year old bulbs.Now ALL lighting works.

 

[RomanH]

Good job Ken!
The aluminum foil fix was a DPO repair and not worthy of anyone who is a member of this forum! /ubbthreads/images/graemlins/nonod.gif
I am glad you removed the potential fire hazard and figured out a more proper and permanent repair. These cars are very simple as compared to new ones that you are correct in saying that it is usually a common sense solution that is best. /ubbthreads/images/graemlins/cheers.gif

 

[myspitfire]

Well your right about DPO's,having to fix a few stupid things left over from the last owner,the aluminum foil was a temporary 10 min fix to see if they(the parking lights)would stay on,having stood their for 10 minutes the foil came off & the permanent fix was done.The foil idea was a suggestion from a (i believe)TR6 owner here at the forum.I hope he remove his foiled fix.Andy M said the removal of the fuse block is a pain /ubbthreads/images/graemlins/iagree.gif in the B.Hopefully i needn't have to go that direction,BUT if i have to i will as NOTHING is left hanging concerning my lbc. /ubbthreads/images/graemlins/savewave.gif

 

[Alan_Myers]

Hi,

Personally, I like to use a little dielectric grease on many types of electrical connections, to help prevent future problems. Most auto parts stores sell little packets of "spark plug boot" grease, which will work. I've also found "light bulb" grease in small tubes at hardware stores. Yes, I use it on light fixtures around the house, too. Wherever it's used, you don't need much. Just a light coating.

What really brought me around to using dielectric grease was working on cameras, many of which have ultra low voltage, battery powered circuits. In addition, many rely upon alkaline batteries which can be very corrosive. The grease really helps protect the contacts and insure consistent power flow.

Often contacts in these and all sorts of applications were originally coated with some sort of anti-corrosive - perhaps zinc plating, chrome or some other coating - that helps maintain good electrical contact. Over time, as corrosion builds up and is cleaned off repeatedly, the protective coatings are removed. The bare brass or steel underneath is much faster to corrode. This won't happen nearly as quickly if a light coating of dielectric grease is used.

Dielectric grease works well on all levels of voltage: cameras running at 3V and less, automotive 12V circuits, household 110V and 220V (ever have a light bulb frozen in a socket?), even high voltage 40,000V (and up) automotive high energy ignition circuits. In broad terms, the higher the voltage the more likely corrosion is between contacts in the circuit. On the other hand, really low voltage and delicate circuits are more easily effected by almost invisible amounts of corrosion.

So, IMHO, dielectric grease is worth a try and will also help keep spark plug boots from adhering to the plugs, helps seal out moisture that can really accelerate corrosion with many types of connections and will delay electrical connections from "welding" themselves together.

/ubbthreads/images/graemlins/cheers.gif

 

[kc_doyle]

LOL the problem as I see it is that it's Lucas. The Prince of Darkness. /ubbthreads/images/graemlins/smile.gif

KC Doyle

 

[Joe_Pinehill]

Your not alone, I spent three nights trying to trouble shoot my horns, replacing switch, buzzing the wiring, till it dawned on me that other units on the same circuit were not working. Eureka, replace the blown fuse. Sometime the easiest answer isnt the most obvious. New to my spitfire, I cant even remember the last time i had to change a fuse on my daily drivers if ever, (mazda and volvo)

The fuse did blow again, and this weekend, I disconnected everything except the hazard lights, (seat belt buzzer, cigarette lighter, boot lamp harness). The boot lamp was removed by the previous owner, and the leads were dangling, I taped them up. My guess is these wires or the cigarette lighter, are the most likely cause of the short.

I was going to plug the units back one at a time every two weeks, and try and pin point the short.

 

[PATR8]

not a spitfire but on my 8 I was having trouble with my radio and brake lights, they were some how on the same fuse. The bow was out of an 7 cause the prior owner melted the 8's box. I wnet out and bought a new fuse box with modern fuses and doouble the number of fuses. I sat for over 4 hours trying to figure out the fuses and wiring, even with the help of my 8 manual it was impossible. I still intend to swap the boxes but I will look at doing it in the winter once I have it tucked in the garage and not risking losing it for a driving time

 

[myspitfire]

Thats a great common sense idea Alan,I will use your suggestion right now everything(lighting)is working fine.I loaded all the circuits a few times,nothing occured so i'm good. /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/savewave.gif