Ford Wiring Dilemma

[arefftx]

The fuse attached right past the starter blows out continuously on my recently purchased 1930 Sport Coupe. Today I replaced the wiring from terminal box to ignition, starter to generator and last week the lighting harness. I disconnected the light switch attachment and the horn to see if any of them were the problem.....no luck still blowing the fuse. I followed the Andrews Manual and a MAFCA printout to make sure all the wiring was as it should be installed. The starter works OK so it is something past the fuse box.......what should I try next? I never met the previous owner but think he was the caretaker for a car he didn't know much about, an interesting side note is I have a paper trail on the car that traces registered owners (3) back to 1953.

Perplexed Alan

[Gary WA]

Originally Posted by arefftx

The fuse attached right past the starter blows out continuously on my recently purchased 1930 Sport Coupe. Today I replaced the wiring from terminal box to ignition, starter to generator and last week the lighting harness. I disconnected the light switch attachment and the horn to see if any of them were the problem.....no luck still blowing the fuse. I followed the Andrews Manual and a MAFCA printout to make sure all the wiring was as it should be installed. The starter works OK so it is something past the fuse box.......what should I try next? I never met the previous owner but think he was the caretaker for a car he didn't know much about, an interesting side note is I have a paper trail on the car that traces registered owners (3) back to 1953.

Perplexed Alan

try removing the fuse holder completely from the system. Did it run prior to your replacing items? positive ground at battery?why did you change out the items?

[Tom Endy]

The attached link might be of help.

Tom Endy

http://www.santaanitaas.org/wp-conte...Quick-easy.pdf

[PotvinV8]

Pull the instrument panel off and make sure nothing is shorting against the tank. If the car has been converted to a keyed ignition switch as opposed to the pop out switch, space can be very tight. Either way, ensure that the backside of the ammeter and ignition switch connections are completely covered so they can't short against the tank.

Are you running an alternator or generator?

[nkaminar]

Use the ohm setting on your multimeter to find the short. This is detective work. Disconnect things one at a time until you no longer have a short. The last thing you disconnected is the problem.

[Keith True]

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Pull the battery wire off the generator cutout and see if it still does it.Right now the fuse is doing it's job.If you eliminate it and hook the wiring up direct without finding the problem your wiring will become the fuse.You will be letting the smoke out of the wires instead of just that little glass tube.

[ndnchf]

What size fuse are you using?

[TerryO]

Originally Posted by Keith True

Pull the battery wire off the generator cutout and see if it still does it.Right now the fuse is doing it's job.If you eliminate it and hook the wiring up direct without finding the problem your wiring will become the fuse.You will be letting the smoke out of the wires instead of just that little glass tube.

+1...That is the quickest way to find the trouble..


TOB

[1crosscut]

Does the fuse blow immediately upon installation?

[TerryO]

Put a 6 volt trouble light in place of the fuse and when it goes out you have found the problem...Much cheaper than replacing fuses...


TOB

[baba]

I have the exact same problem with my 29 coupe, will follow with interest. I printed out the attachment in Post #3, thanks Tom

[arefftx]

Today I will use the suggestions made and try to isolate my problem....to answer the questions:

I am using a 30 amp fuse
I have a generator
The fuses blow immediately after replacement
I have never had the car running

Thanks for all the suggestions!

[Badpuppy]

Check the cutout for short. That's them main reason for installing the fuse, to prevent the battery from discharging into the generator. A relay cutout may be refurbished, but a diode type is less troublesome.

[rotorwrench]

Most of these fuse kits come with a 20-amp fuse. If you want to troubleshoot without an OHMs meter then I'd suggest going to the local parts store and purchasing a 20-amp short stop circuit breaker and use small jumper leads to put it in the circuit in place of the blown fuse. These breakers open under short and then reset after they cool off. This will keep you from having to purchase innumerable fuses.

With an OHMs meter, a person can isolate each wire and test both for continuity through the wire and for short to the car body/frame ground. Any other way will blow fuses till you find the bad wire or wires. On wires in covered bundles, it's a good idea to isolate all of them and then check each one to the others for signs of cross shorting due to bad insulation somewhere in the bundle.

I've seen more than a few instrument panel light wires shorted to ground so do as previously mentioned and look in there for problems.

[katy]

Check the brake light switch. I've read that some of the reproductions can be problematic.

[TerryO]

Most of these fuse kits come with a 20-amp fuse. If you want to troubleshoot without an OHMs meter then I'd suggest going to the local parts store and purchasing a 20-amp short stop circuit breaker and use small jumper leads to put it in the circuit in place of the blown fuse. These breakers open under short and then reset after they cool off. This will keep you from having to purchase innumerable fuses.

Thats why I use a light...you can see it from the other side of the car and it doesn't have to cool off before you can continue trouble shooting.


TOB

[rotorwrench]

A light may not find a short easily. It will tell a person that there is power coming through a wire or not but it could still blow fuses till you find the bad wire. It isn't very helpful on cross shorted wires either.

[arefftx]

There are the tests I have do to determine why I am blowing fuses. I hooked up the horn wire to the cutout alone, it didn't blow a fuse, I then added the wire from the terminal, it immediately blew a fuse. I removed the instrument panel and left it detached to make sure it isn't touching any metal. I checked all the wires with an ohm meter they all test 000. I checked all terminal box wires , non loose or touching metal. Removed the distributor cable to check to ignition it is Ok. Light bail is disconnected hanging free. Suggestions?

[Bob C]

Like was mentioned before disconnect the stop light switch.

[arefftx]

Just removed the brake light wiring....blew another fuse!