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Tue Mar 18, 2014 8:40 am

I'm going to install a fuse inline to the ignition hot lead to the coil. What would the appropriate size be 5amp..10..15 for this?

Tue Mar 18, 2014 8:57 am

It powers coil, idle solenoid and choke.. on most..
Use a 10 amp fuse...
and BTW... very good choice to add a fuse..
Its one of at least 2 fuses I always add...

Tue Mar 18, 2014 9:02 am

I added mine up in the trunk at the fuse box connection, so the fuse will protect the coil wire that runs back through the VW body. If you add at the rear, theoretically you could ground out the wire just "upstream" of the in-line fuse and still burn all that stuff up.

Tue Mar 18, 2014 9:06 am

Great idea - do you use the same type of fuse as in the car's fuse panel? Or one of the glass ones?

Thanks,

Victor

Tue Mar 18, 2014 9:15 am

I use modern "Mini" fuse folders and fuses..
And yes... you always add a fuse as close to the voltage starting source as possible to protect the entire circuit....

Tue Mar 18, 2014 9:24 am

What wire on the fuse block is it?

Tue Mar 18, 2014 10:11 am

What car are we working on here..... :?

Tue Mar 18, 2014 10:36 am

Don't mean to hijack missourimark's thread...for the record, my daily driver's a '72 Super and I also have a '64 sedan.

Tue Mar 18, 2014 10:58 am

VOLKSWAGNUT wrote: It powers coil, idle solenoid and choke.. on most..
Use a 10 amp fuse...
and BTW... very good choice to add a fuse..
Its one of at least 2 fuses I always add...

I just got a fuse ($6.00) kit from the classifieds here... good quality wire & 10a glass fuse that I'll be installing when things warm up.
What's the other circuit you think is a good idea to protect?

Tue Mar 18, 2014 11:35 am

I have a 1973 standard bug

Tue Mar 18, 2014 12:05 pm

jlex wrote: VOLKSWAGNUT wrote: It powers coil, idle solenoid and choke.. on most..
Use a 10 amp fuse...
and BTW... very good choice to add a fuse..
Its one of at least 2 fuses I always add...

I just got a fuse ($6.00) kit from the classifieds here... good quality wire & 10a glass fuse that I'll be installing when things warm up.
What's the other circuit you think is a good idea to protect?

Wrong forum...but....Pre 68... Park lights (front) are not fused.. I either tie them into the tail light fuse or add a seperate inline fuse.
Also the Speedometer indicator supplu isnt fused.. but its such a short distance..its generally not an issue.

missourimark wrote: I have a 1973 standard bug

If your car is connected properly.... Fuse 11 and 12 are bridged on the INPUT side of the fuse panel. (Inputs are not the protected side).
11 & 12 are the Ignition On Supply from the ignition switch.
The 12 volt supply for the coil should be at the INPUT to fuse 11.
Black wire.
You would install a fuse between the Fuse block terminal and the Coil circuit. Basically create a jumper with an inline fuse. No cuttting involved.

Key on... Use a test light at the rear on the coil Ignition SUPPLY.. (15 or +) Test light should light... and unplug the wire mentioned at the fuse block...light should go out...
Thats the easiest way to tell....in case its been altered or you are unsure.

Tue Mar 18, 2014 12:13 pm

Did some searching found the correct wire and we're good to go on the fuse. Glad I did this cause alot of folks on this forum reccomend this. Thanks to all!!

Tue Mar 18, 2014 1:01 pm

"I'm going to install a fuse inline to the ignition hot lead to the coil."

I've been on the edge of doing this for years. I can't make up my mind. The only reason I figure VW didn't fuse the line is maybe they didn't want a fuse to lose contact or blow while you were passing on a two lane road.

I've protected the connectors in the engine compartment with plastic tubing and soldered all connections. I try to be careful. My brother fused his and has had the fuse lose contact on several occasions over the years. No big deal, he just goes to that fuse and tickles it.

Still, unfused lines seem like a bad idea. After fusing their line, has anyone had any unforeseen problems or consequences?

Tue Mar 18, 2014 1:04 pm

You can also check to see if you have an inline use between coil and backup switch near the nose of the tranny.

Tue Mar 18, 2014 1:52 pm

goober wrote: "
I've been on the edge of doing this for years. I can't make up my mind. The only reason I figure VW didn't fuse the line is maybe they didn't want a fuse to lose contact or blow while you were passing on a two lane road.

I've protected the connectors in the engine compartment with plastic tubing and soldered all connections. I try to be careful. My brother fused his and has had the fuse lose contact on several occasions over the years. No big deal, he just goes to that fuse and tickles it.

Still, unfused lines seem like a bad idea. After fusing their line, has anyone had any unforeseen problems or consequences?

Electricity flows the path of least resistance... Originally...If the coil circuit shorts.. It will loose coil fire due to loss of current flow and voltage.. Its all being lost at the short to ground.
Then.. the harness begins to melt down... melting every wire that the igntion supply circuit comes in contact with it to the point of the short.. If you're lucky it wont destroy your ignition switch or its battery supply circuit... or...

In other words.. while you were passing on a two lane road.. and it shorts.. you now are pulling over and putting out an electrical fire...

Ill change my fuse... any day over that...

I have NEVER understood why Vw did not fuse this circuit or at least have it on a circuit breaker..
I deal with correcting Engineering mistakes every day...I've learned dont ask why they didnt do this or that... .. just fix it and make it better in the field..

As for having to "tickle" the inline fuse... thats why I DONT use glass fuse holders..
A capped weather pack "Mini" or "ATO" fuse holder required no tickling... :lol:

Tue Mar 18, 2014 4:56 pm

goober wrote: My brother fused his and has had the fuse lose contact on several occasions over the years.

That is why you use modern blade fuses instead of the crappy stock ceramic and glass styles.

I use a 20 or 25amp in mine as it also has the reverse lights to cope with.

25amp is enough that it will blow from a short before it melts the wiring but would take a lot to blow it just from overloading the circuit so wont cut out mid 2 lane overtake.

I also add an inline fuse on the instrumentation light wire as again replacing a fuse is easier and cheaper than replacing the light switch with a burned out rheostat.

Tue Mar 18, 2014 6:01 pm

Joel and Ken - is this the type of adapter you use for the inline fuse on the ignition?

http://www.cbperformance.com/ProductDetails.asp?ProductCode=2450

Thanks,

Victor

Tue Mar 18, 2014 6:29 pm

vamram wrote: Joel and Ken - is this the type of adapter you use for the inline fuse on the ignition?

http://www.cbperformance.com/ProductDetails.asp?ProductCode=2450

Thanks,

Victor

Yes, any NAPA or similar has a shelf full of them, Walmart probably also.

Tue Mar 18, 2014 8:14 pm

Thanks Cletus. No NAPA round these parts, but I bet Autozone carries it.

Wed Mar 19, 2014 5:14 am

You might also want to consider installing a fuse, fusible link or circuit breaker into the heavy gauge wire that runs from the battery positive terminal to the VR or 4-way junction below the rear seat. Except for the starter, this one wire carries the current for everything else. This will need a BIG fuse. I have a 50A fuse for a large stereo amp installed.