Park / tail lights fuse keeps blowing

[David F]

Tell me again who has the  attitude?  I know how to use the meter.  Thanks anyway.  I wanted help, not arrogance.  Not sure how you came to your conclusion from my first post.  Obviously you are not the one to help me.

[SteveJ]

It's not arrogance. It's your ignorance. I know what I'm doing. Claiming that you know how to use a meter and understanding the results are two different things.

You measured resistance from the parking light circuit (constantly hot) to other wires that also go back to the battery, and you don't know why they have continuity. Hint: They are all connected together like they are supposed to be. Study the wiring diagram. I have.

You think that a dead short between the fuse box and the combo switch (the description at the start of this thread) is the same as an overloaded circuit. (And I have documented in detail one possible cause for the parking light circuit overload on this board.)

I told you to get a tool to help you with diagnostics, and you say that you don't need to because your meter tells you what you need to know. I'll give you another clue. I'm interested in current flow, not voltage or resistance. If you have a typical multimeter, it goes up to 10A. If you tried to hook it up to the parking light circuit in its current condition, you could blow up your damn meter. The brightness of the test light can be used as a relative measure of current. On the other hand, you could buy a clamp DC ammeter that has a high enough scale. A decent one will run you about $40 or more, and you will have to learn the limitations of the meter. Test lights are cheap, and you can get them from any parts store on the way home from work.

And yes, it is attitude when you claim to know what you're doing when in reality you are just guessing wildly. It's still attitude when you are indignant when you are called out on your ignorance.

If you want help, you have to pay attention to what people tell you to do. If you do not want to follow instructions that will identify your problem, then you are correct that I am not the one to help you.

[JSM]

2 hours ago, David F said:

Tell me again who has the  attitude?  I know how to use the meter.  Thanks anyway.  I wanted help, not arrogance.  Not sure how you came to your conclusion from my first post.  Obviously you are not the one to help me.

David, Steve really knows what he is doing. He would not steer you wrong in anyway. 

It's hard to convey tone over the internet. He is only trying to help. 

[grannyknot]

@David F How about you start your own thread on the electrical problem you need help with?  Then people can choose to help or ignore you without cluttering up the OPs thread.

[Patcon]

18 hours ago, David F said:

Tell me again who has the  attitude?  I know how to use the meter.  Thanks anyway.  I wanted help, not arrogance.  Not sure how you came to your conclusion from my first post.  Obviously you are not the one to help me.

@David F

Unless you're an electrical engineer with 30 years of experience then you might want to listen to SteveJ. He has forgotten more about electricity than most will ever know. There is a method to his questions to locate the problem quickly

Also Grannyknots suggestion is a good one for a separate thread. That is generally accepted forum etiquette...good luck

[David F]

The issue has been found and corrected with the help of forum member via PM and my trusty VOM.  I do apologize to the OP for hijacking his thread. 

[wil84911]

The issue has been found and corrected with the help of forum member via PM and my trusty VOM.  I do apologize to the OP for hijacking his thread. 

No worries. All good. Glad to hear you fix your issue.


12/71 2.6 block E88 heads triple weber 3/2 Mallory Abarth Tokico 1-3/4 sways

[wil84911]

Why do you expect the problem is around the fuse block?  In electrical troubleshooting, the first thing to do is isolate. In this case, remove the cover from the steering column and disconnect the 6 wire connector on the headlight switch. Use a test light across the fuse and see if it lights up. If it does, continue troubleshooting.

Let's follow your hunch about the fuse block. Disconnect your battery and remove the block. Look for debris that could touch the inner side of the fuse to the chassis. If you don't see anything there, it's likely in your dash harness.

If it's the dash harness, chances are that the green/blue wire has been chafed somewhere or someone tapped it as a continuously hot source. (Think aftermarket radio here.) Where the wire was tapped may have some bare wire that is coming into contact with the chassis or dash frame.

 

 

 

Update: followed all suggestions but haven’t found anything yet though I am about to unwrap the harness wire. Sorry I’m slow due to busy schedule and electrical is not my thing.

 

 

 

12/70 2.6 block E88 heads Mallory DCOE40 3/2 Abarth Tokico 1-3/4 sways ext oil cooler

 

[Mikes Z car]

  Some of my own troubleshooting techniques are done as much for entertainment and learning as they are for fixing things.  Some of my techniques I would not want to publicly disclose!  (no I don't use a ouija board)  Anyway how about hooking up a test light across the fuse, maybe at night and then gently feel around under the dash and push the wires around looking for a brief change in the test light brilliance.  Just an idea.  The FSM seems to show that 12V for the lights goes two places, from the fuse to the combo switch and also to the inspection light under the hood.   

  I love solving  electrical gremlins.

Edited October 29, 2017 by Mikes Z car
fix typo

[wil84911]

....The FSM seems to show that 12V for the lights goes two places, from the fuse to the combo switch and also to the inspection light under the hood. 

 Voila!!! That was it.. the inspection and probably due to melted wiring. Totally forgot recalling reconnecting it and I guess this was the reason why it was purposely disconnected in the first place. Feel a little embarrassed with all that diagnosis. I was getting frustrated but sat down and reread the replies.

 

Thanks so much EVERYBODY [emoji4]

 

 

12/70 2.6 block E88 heads Mallory DCOE40 3/2 Abarth Tokico 1-3/4 sways ext oil cooler

 

 

[JSM]

Awesome. Simple after all.  This is a Good lesson to remember.