Fuse....

T

txmike

Senior Member
I am burning 30amp fuses like a kid eating candy.

I tried a 35amp fuse and at least get power to check on some other things like brakes lights etc

Am i setting myself up for a fire if I try to run it with a 35a?

thanks again
Mike

:eek:
 
txmike said:
I am burning 30amp fuses like a kid eating candy.

I tried a 35amp fuse and at least get power to check on some other things like brakes lights etc

Am i setting myself up for a fire if I try to run it with a 35a?

thanks again
Mike

:eek:
Click to expand...


YES YOU ARE

DO NOT increase the fuse size!!
 
Disconnect all circuits from the known buss then reattach each one by one to see if one blows the fuse.

The model A has a simple system compared to later cars. A person can check each wire to ground with an ohms meter to see if there is a dead short. Wires that are close together can be checked for cross shorting also. A person can check a system out with no connection to the battery if they do it this way. Individual wires should be isolated to do the checks.

I use my multi meter a lot and I have lots of jumper leads of all different lengths to check out individual conductors. The lighting system is the most common culprit due to the amount of current conducted and the amount of separate lighting circuits. It's more simple if you only have one tail lamp since there are only two wires that follow the frame back to it. Headlamp wiring runs inside metal conduits and along the radiator so there are multiple places they can short plus the horn wire that is hot all the time.
 
Start by disconnecting your light circuit at the generator. If that clears it up, go after that circuit.
 
I agree. As mentioned, I wouldn't recommend a 35 amp fuse. As said, isolate the circuits and see which has the problem. Since you didn't mention anything in particular I'm thinking its something like headlights, horn or brake switch feed..
 
Get yourself a 5 volt buzzer. Put that in series with the battery, it should buzz. Then start disconnecting things until the buzz stops. There's your trouble.
 
It may be that you have a poor ground on the battery that is allowing the generator voltage to run wild. Check the connection of the ground strap to the frame. It is out of sight and may have been neglected for years and become corroded and supplying a poor ground.

Remove the battery to access the cable. Remove the cable from the frame and wire wheel the end along with the nut and bolt. Clean the mounting boss on the frame so that it is bright shinny metal. Also clean the power cable and the battery terminals.

Tom Endy
 
Lots of great suggestions..... now off to the races and I will report back
thanks for the help
Mike
 
I appreciate the advice. Now that you tell me i understand better but when it comes to wiring and positive/negative etc I am not the guy you want doing your work.

I disconnected wires and believe it is something to do with the starter switch. I believe pictures are worth a 1000 words. Take a look at the pics...

When you look at the rear of my switch you see three connections and two screws on the side that look like ground wire hookup? I have two wires. One red and one black with a blue connector. Hook up the red - no issue. When I hook up the black wire i have a problem.... the fuse starts getting hot etc.
Are they on the wrong terminals?
Bad switch?
Does the switch need a ground wire?

Other pics are added just in case in attachment....
 

Attachments

That black wire goes to the distributor through the armored cable. It is probably shorting on the armored cable housing.
 
You have an aftermarket ignition switch.


Does this happen with the key only in the "on" position or all the time?


Did you just install the ignition switch , if not, what was going on when this started. Had you been doing other electrical work on the car?


As stated by WMWS, I suspect the black wire goes to the distributor and something is shorted in the distributor or the armored cable. if there is one.


If this happens no matter if the key is either in the OFF or ON position, I may be the switch itself. If it does not happen when the key is in the OFF position, there is a problem with the black wire or something inside the distributor itself.


My opinion,


Chris W.
 
Thanks guys - i did not just install the switch.
i can order a new armored cable but while I am at it why not replace the ignition - right?

You mention "aftermarket"

Is there are particular type I should be seeking
 
If a person is going to install a conventional ignition switch, the system really should be modified to connect the distributor directly to the coil and install the power wire in the switch circuit like all the later cars from the model B on. The model A is one of the few cars that switched the breaker side of the ignition circuit through the armored cable of the electro-lock switch.

On the original model A vehicles, the coil was connected to power all the time but it was only hot when the breaker circuit was turned on.
 
rotorwrench said:
If a person is going to install a conventional ignition switch, the system really should be modified to connect the distributor directly to the coil and install the power wire in the switch circuit like all the later cars from the model B on. The model A is one of the few cars that switched the breaker side of the ignition circuit through the armored cable of the electro-lock switch.

On the original model A vehicles, the coil was connected to power all the time but it was only hot when the breaker circuit was turned on.
Click to expand...

I agree 100%.
 
I had a similar issue and found my horn wiring grounded as the leads to the brushes were touching the horn motor housing.
 
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