I pray they upgraded the wiring, but from what I have seen with Chrysler probably not.

From an engineering standpoint, if you have to compensate for inrush current ( startup surges ) you keep amp rating the same, but switch to a slo-blow ( delay ) fuse.

You do not up the current rating of a fuse to compensate for surge current.

I can see the benefit from a safety standpoint. If you install a lower rating and it runs fine, should that fuse blow at some point it would indicate an impending problem ( fan motors getting old - might be time to replace ). If you have the full rated fuse, then when it blows you DEFINITELY have a issue, right now!

 

Yup.

 

UPDATE -

Well I got a little more intel on events at time of failure.

The problem with the ACCESSORIES not power on while running came up. My son told me he was 'jiggling' the switch at time of failure.

My guess he was jiggling it a bit too much, and BANG !!!!!

That little bit of info gives me hope that putting in the new switch will be the remedy.

Off tomorrow, so tomorrow is the day we play with it!!!!


.

 

I spent a lifetime working in electric ( and some mechanical ) engineering.

Almost none of what I worked on was land based .... it flew, some of it all the way into outer space ..... way outer space.

If we built those items the way Jeep builds it's vehicle, our Space program would never get off the ground.

" If it's worth doing ..... it's worth doing the right way the first time. "

The most enjoyable work I did was in failure analysis and reverse engineering.

 

I hear ya. In another universe a long time ago, I installed a cell phone (back when they were installed) in a Saab.

That thing was a joy to work on. The wiring was mil-spec. All number coded instead of color-coded. Every wire went into a loom precisely, and came out precisely. No tape anywhere. Nice stuff.


Yeah, that's fun stuff.

 

Jeeez...you are a rocket scientist.

 

Nah .... just an electrical engineer!

But I did spend time with a few rocket scientists .... those fellas a looney.

Oh and a few physicists as well, those guy are extremely book smart but lack common sense.

I questioned why I was hired to work with that group, after all they all held PhD's in their field and I was the only one who held a lowly BSEE. I was told by the lead Physicist " we hired you for your common sense, and years experience in testing things till the broke, and explaining why they broke. "

Complicated crap I am comfortable with ..... but a simple thing like a Jeep and I ask questions.

I do have a background ( self taught out of poverty ) in auto mechanics ..... but that dates back to the 1970's before the average person even knew " computer " was a word.


OH and in this case ..... it appears as if the ignition switch has suffered an internal failure allowing things to 'float' .... lots of discolored metal contacts from excessive heat and burned and melted plastic around the contacts. Spoke with someone a little more knowledge on these things and he said the reason it blew the 60 Amp fuse was most likely the internal shorting caused too many things to power up at the same time.

The 'junkyard' switch I got this time is a Chrysler part ..... the last one was definitely aftermarket.

I'm gonna go find another Chrysler part .... dismantle it and compare it to the aftermarket one, pretty sure I will be able to determine why it failed.

 

Long ago when vehicles were simple, and I had access to all sorts of mil-spec stuff ( 1979 ) I had a 194 Chevy half ton pickup with a 454 cu in big block. Too poor to pay anyone to work on it ( I was a lowly enlisted man in the US Army ) I had to pull the heads when it dropped a valve due to an exploding valve 'keeper'. Luckily the valve did not fall far, but it was bent and pushed back up into the head. So I pulled the heads, figuring if I got in over my head I would only have to pay for half the job .... after all I already took it apart. Well I sent the heads off to be rebuilt. When they came back, I installed them by the book along with all the other crap that had to come off. Then the moment of truth came ..... time to turn the key and BINGO ..... she was running better than ever.

That was my 'mechanics test' .... LOL

Oh after them we set about redoing all of the electrical on that truck .... any harness connectors that could be changed, we changed over to mil-spec.

It was fun to do but thinking on it now .... at some point, somebody got that truck and had to do some work ...... found those military connectors and went ....

 

Way back in my days of callow youth, someone in our group of cellular network engineers took the above cartoon and replaced the words, "rocket scientists" with, "cellular engineers".

I think that was when we were first getting into CDMA and our brains were exploding from trying to grasp the concept of getting a usable signal from under the noise floor.

 

It was obvious the switch was bad ...... the sparks and smoke coming from it told me that. It was not obvious that it was the ONLY problem and in fact it may not be.

More to come as another symptom has appeared relating to one of the circuits on that 60 Amp fuse!

Chrysler/Jeep and their wiring harness design/building geniuses!

Build em cheap, let em burn!

 

Unrelated to the problem at hand, and I do apologize BUT....

Ken, I've been trying to find a replacement for my combination buzzer, but the part is discontinued. I've tried several parts websites, rock auto, and even a general google search - all ending with the same result of "part no longer available." Is there ANYWHERE I can find a replacement or do you know of an alternative? I always liked the sound the buzzer in the GMT400 made... but I don't think that will work.

 

Next time I take a walk through the Parts Park ( junk yard ) I will look for some of those, pull one and send it to you .... should know within the week.

 

You heard it here first, folks!

 

LOL.

I part these things out all the time and I've never thought to save the buzzer...Dang.

 

I thought I had a couple of those buzzers here, but I have the other round buzzers.

I generally get the little things, like relays, large fuses, connector/pigtail for those known to burn, trim specific screws and the like.

People must lose a lot of screws, I am shocked at how many jury rigged dashboards I see with the wrong hardware in visible places.

It must be real hard for some folks to keep track of what they remove from their vehicles while they work on them.