[Cliff R]

I developed a problem with the trailer lighting on my Nissan Xterra. No running lights at the 7 pin connector. No big deal I thought, probably just a problem at the plug or one of the connectioins, or even better a relay or fuse.

I will say that vehicle wiring is NOT my speciality nor am I very good at it, but can usually fudge my way thru it.

So I check all the basic stuff, fuses relays, connector, connections back by the spare tire, etc. No voltage anyplace for running lights. So I remove the kick panel and check the relays under the glove box, no voltage at the relays but I was getting voltage to close the one for running lights when you turned the lights on.

Well that's not good as all the fuses checked out in all three fuse boxes. Hum? So I go back thru all of them again and all fuses show good. This process took at least half a day so I'm stumped. I go on-line and look at a couple of videos and low and behold there is one where the owner has the exact same vehicle and exact same issues. He's gets stumped as well then finds a Forum telling him to check a fuse that is BURIED in the bottom of the large fuse box under the hood. The fuse is NOT visible or accessable without pulling most of the connectors apart and out of the way. Even then you can NOT pull the fuse with anything but a scribe.

So the story has a good ending, aside for the fact that you have to be a magican to get the new fuse installed.......

https://www.youtube.com/watch?v=AH2YhkEfO68

[Half-Inch Stud]

Fantastic then. Crappy design revealed.

[61-63]

When I run into something like that I want to string up the engineer or whomever was responsible for designing it. Now why would some damn fool decide to bury a fuse at the bottom of a fuse box where you can't see it?

[Cliff R]

When I run into things like this I want to put the engineers nuts in a shop vise who came up with that crap!

ABOLUTELY stupid to bury fuses out of site under the ECM and all it's wiring. Even with a schematic I was not finding them and just figured my vehicle didn't have those fuses because it was not originally ordered from the factory with a towing package. That part of the story fall under the NEVER assume anything catagory so I will accept some fault there.

I had added the 7 plug connector, trailer brake controller, and wiring harness under the kick panel with the relays a few weeks after buying it. Would have NEVER in a million years found that fuse or even thought to take all the watertight plugs in the fuse box loose and look UNDER them...........

[sdbob]

I feel the same. Only reasonable reason is $$$$ for dealership. I thought I was only one. Mine is my GMC 2500 horn works intermittently,corrosion they say from internet. There is a connection under drivers side in front. Behind bumper. On mine I need to remove small plastic filler panel above bumper below steel fender or bumper. If not you just cant get your fingers in to clean I've just soaked connection with cleaner. Works then quits. Ugh!

[Mr Anonymous]

youre certified now

[Keith Seymore]

Originally Posted by 61-63

When I run into something like that I want to string up the engineer or whomever was responsible for designing it. Now why would some damn fool decide to bury a fuse at the bottom of a fuse box where you can't see it?

Originally Posted by Cliff R

When I run into things like this I want to put the engineers nuts in a shop vise who came up with that crap!

Oof. Tough crowd.

I wouldn't dream of "white knighting" the guy responsible for this design, but in all seriousness there are a lot of constraints that we hobbyist can't imagine.

Maybe he was forced to re-use a design from a different model, or earlier version of this model, to save on piece cost and tooling investment.

Maybe there was a layered build in the assembly plant that required installing the bottom portion of the fuse box first and the top part later, in order to avoid relocating heavy equipment ("monuments") in the assembly plant.

Just a couple examples off the top of my head. It is way different designing for a thousand or tens of thousands of vehicles (or, in my day, a million a year) than it is for just one.

K

[Keith Seymore]

Example:

Originally Posted by Keith Seymore

There are some "architectural" things we did, too, that you might not notice. These were required to even give us a shot at getting in the game.

The '96 and beyond GMT400 models had the round element air cleaner on top of the fender, with the battery in the RF corner (passenger front) of the engine compartment.

It became obvious to me that I needed a flat filter in that spot to minimize the turns in order to even have a chance at meeting the aforementioned very aggressive flow requirement. So - I started a movement to displace the battery to some other location. Naturally the battery guy wasn't very happy about that.

We were stuck in a stalemate until the Chief Engineer, Ken Sohocki, took notice and called us into his office. He made each of us pitch our idea. In my case, I had actual flow data generated on the bench using rapid prototype material, and could demonstrate the effects with objective test data. The battery guy's response: "but we've always been right here".

The Chief's direction was swift and clear: "Seymore - you get the front corner. Schaule - find another spot".

So he moved the battery to the front of dash (rear of the engine compartment) so that he would have some structure to support his bracketry.

The engine air induction has been in the RF corner since that time, for GMT800, GMT900, K2 and now T1 generations of full size truck.

K

Originally Posted by Keith Seymore

We weren't out of the woods yet, however.

The next hurdle was that the engine coolant overflow bottle was on the front of dash. That allowed the assembly plants to evacuate and fill the coolant system prior to fender install.

With the battery now on the front of dash that meant the coolant bottle had to move somewhere else, the only other place being top of the wheelhouse on the RH fender. Unfortuately that meant you couldn't fill the sytem until after the fender was on - or - you had to move the filling station. That wouldn't work because it was one brazillion dollars to move a "monument" per plant times 7 truck assembly plants = 7+ brazillion dollars.

So here is what we did: we developed a way to "stage" the coolant bottle on the radiator support temporarily by adding two "buttons" on the rad support and a corresponding tab on the bottle. The bottle could be hung in this temporary location, evac and filled, and then moved to its permanent location on top of the wheel house after the fender was installed. Problem solved, with no tooling change and pennies in piece cost.

We briefly discussed if we should remove those buttons or if it made more sense for them to remain on the truck for the life of the vehicle. In the end it was cheaper and didn't hurt anything, so they stayed. If you look at any GMT800 fullsize truck you should see those two buttons on the back of the rad support, just going along for the ride.

K

K

[Keith Seymore]

I'm sorry - one more story even though it's way off topic:

Seeing those stylish ribs on the engine cover and air cleaner box reminds me: the GMT800 was really our first occasion to work with the design studio and incorporate "underhood beauty" for trucks.

I worked on the program for about 4 years. When I started in 1994 the underhood designer had created a cover with stylized ribs which were indentations, or grooves, rather than what you see here.

By the time we finished "ins" were "out" of fashion and "outs" were "in", so I had to redesign the top of my air cleaner box to match the new engine cover.

Also - the top of the box might look flat, but it is not. Flat surfaces often will look caved in when placed in context, so it actually has a HUGE radius (like 5000mm) so that it is curved outward rather than actually flat.

K

[turbo69bird]

I check forums and or YouTube before every project. I learn much better from video than book and others real world experience usually proves much better anyway. Not that I won’t consult a manual also but videos usually show more real world situations w cars.

As for engineers they have their place but typically what happened on paper and what happens in the real world are very different . As a builder I’ve had many a project designed by engineers architects that woukd never have worked in the field. Had one house that for 20 years was built a certain way engineers architects said the only stair case they could fit was a straight long staircase nothing else would meet code.

People hated that feature in the house but loved the house so much they build it anyway . So I built the design for myself finally and I built the staircase myself, Put a turn in it about 5 stores down and fit it all and passed code . People would have been so much happier with this design for all those years.

Glad you were able to fox your problem and happy someone posted a good way online to help others

[Keith Seymore]

I'm reminded what a team effort all that was.

I was forever going to the fender guy and asking for hole modifications: first - for a hole to flow air through, and then subsequent re-asks for bigger holes and shape changes. It got to the point if he saw me coming down the hallway he would duck into a conference room and hide out.

My development guy is the one that thought of the button thing. He's also the one that developed the noise tuning devices that we incorporated.

My supplier engineer from Delphi became a close lifelong friend that I am still in contact with, nearly 30 years later. His whole family were antique auto enthusiasts. I was sure by the time I was done with him he would be drinking Coca Cola and driving muscle cars. The reality of what happened is I bought a '31 Ford and would drink Mountain Dew with him.

I say all this to say: it's not just one guy. There are several close knit members on the team, and several layers of management within engineering, and several other discplines (purchasing, planning, logistics, containerization, assembly representatives, etc) that these decisions have to get through.

Even when you hear "Harley Earl did this" or "Bill Mitchell did that", or Larry Shinoda, or even Mac McKellar, you have to remember there was a whole team of people underneath them doing the "actual" work.

Or - maybe the guy really was a doofus and was more concerned about chasing a little white ball around than he was with car stuff. Those guys are the majority, I'm afraid.

[Keith Seymore]

Originally Posted by turbo69bird

I check forums and or YouTube before every project. I learn much better from video than book and others real world experience usually proves much better anyway. Not that I won’t consult a manual also but videos usually show more real world situations w cars.

....

Glad you were able to fox your problem and happy someone posted a good way online to help others

Yes - Cliff I'm glad you got it figured out.

I just spent about a week working on my wife's car (front struts, brakes, coolant leak) and NONE of it was straightforward, resulting in several additional trips for purchases and returns, and at least two different youtube videos.

I am loving that aspect of this internet age.

K

[sdbob]

Thank you for giving me at least an idea all that's involved.

[Cliff R]

Good outcome but without that Youtube video I was DONE!

I was actually going to power up the relays in my harness under the kick panel with separate wiring and put an in-line fuse in route, but glad it didn't come to that.

As good as Youtube videos can be, sadly many aren't that great.

I get ill trying to watch some of the Q-jet videos on there and seldom make it much more than a few minutes into them.

I get some excellent information about shooting pool, a hobby I've been getting more serious about in the past couple of years. There are some really good videos out there if you are into that sort of thing. I've improved my game dramatically just picking up a few basic/fundamental things to add.......

[Shiny]

My oldest son has an XTerra and is enamored of it.. apparently there is a near-cult following. Glad you found the hidden fuse. Youtube is a modern Chilton's for almost everything.

As to squeezing development engineers' nads.... I get it but you might squeeze elsewhere. In my experience, decisions like Cliff's example were forced on the design engineers. Trust me, they knew it was buried and they knew it would be inaccessible.

Please squeeze Industrial Designers, Marketing, Manufacturing, Distribution, Compliance, and in the end, the program and business managers that commit the schedules to the business.

Decisions to accept stuff like this by over-ruling the design engineers usually ended with "Ship It" in my experience.

[Keith Seymore]

Thanks for the encouragement. I never quite know how much to share.

Originally Posted by sdbob

I feel the same. Only reasonable reason is $$$$ for dealership. I thought I was only one. Mine is my GMC 2500 horn works intermittently,corrosion they say from internet. There is a connection under drivers side in front. Behind bumper. On mine I need to remove small plastic filler panel above bumper below steel fender or bumper. If not you just cant get your fingers in to clean I've just soaked connection with cleaner. Works then quits. Ugh!

What year GMC?

On my '04 it is on the the radiator support, RH front under the air cleaner. I popped the airbox out, removed the tray it sits in and had easy access from the top.

I know this because ....my horns quit working, too! I replaced them with horns from a Cadillac limo which I thought were a bit more masculine sounding than the originals.

K

[Cliff R]

Oh I'm sure there would be a list of folks involved in three fuses ending up under all those wiring harnesses and even with them removed it's a "hat trick" to R & R the fuse.

The XTerra's were overbuilt and underpriced for what you get so Nissan killed them off. I suppose they would have a decent following out there. I have the Pro-4X version which comes with some nice off-road stuff including an electric locking rear differential.

My daughter has the same vehicle and it's been flaweless to nearly 150,000 miles at this point. Mine just turned over 90,000 miles and aside from this blown fuse nothing but routine maintenence so far......

[Stuart]

Originally Posted by Keith Seymore

I say all this to say: it's not just one guy. There are several close knit members on the team, and several layers of management within engineering, and several other discplines (purchasing, planning, logistics, containerization, assembly representatives, etc) that these decisions have to get through.

When I graduated from school I interviewed with Chrysler. It turned out the job opening was for a windshield wiper engineer. I hadn't thought about it before then but it took a team of people just to work on that one subassembly, let alone the entire vehicle.

[Shiny]

Cars at least have planned maintenance operations and warranty repairs to help guide those decisions. A lot of products I worked on were designed to be thrown away or replaced during warranty. I'd say design engineers like Keith at least had a fighting chance to influence decisions based on ease of repair/replacement.

In Cliff's case, I'd speculate a management team considered the probability of needing access to that fuse during the XTerra warranty period was so low that the poor design was accepted, and the engineers were told to get over it.

[sdbob]

2015,2500 hd. I've taken radiator shroud off,headlight and another metal piece. But I've found out to get my fingers on the connector(it seems different than Chevy) I need to either remove the bumper ,or drop bumper or remove piece of plastic (could be flexible) rubber filler above bumper below fender. I'm afraid of the plastic piece as it is painted, might crack it. I've tried twice from above.then just sprayed contact cleaner from above.