Why Do Mechanics Hate Mjs?

[armyofchuckness]

I'm a semi-mechanically minded chap. I'm restoring a '64 Valiant in my spare time, and I'm blessed to be gainfully employed enough to have a mechanic handle the more annoying repairs on my daily drivers so I can focus my time working on the Valiant instead. One of the things that appealed to me with the MJ is they seemed to be based off a simple, common platform and have a vast array of parts available (at least for the drivetrain). I've been dismayed to discover that my regular mechanic, back up mechanic, and electrical guy all HATE this Jeep, even flat-out refusing to work on it sometimes. 

 

There's no mods to the truck, and the parts are as cheap and ready to come by as I thought they'd be, yet they all gripe and moan any time I call them about working on it. I never got this from my other cars I've had, and some of them were way more complex and cramped ('03 Neon) or unusual and obscure ('82 Cressida) to work on.

 

So why the MJ hate? Am I the only one that's experienced this?

 

I have a feeling I'll have answered my own question when I get around to swapping out the fuse box (refused job because the money wasn't "worth the effort") and heater valve (another refused job, for unknown reasons other than "You can replace that yourself while doing the fuse box.")

[88whitemanche]

I've never had any problems with someone fixing my truck? Well my only mechanic...I only go to him when I don't have the right tools or some of the knowledge to fix my truck...but other wise no problems even took it to his electric guy and worked on my truck for 2 days with no problems...

[GirsMJ86]

No issues here with the guy I take things to if I just don't feel like doing something. He has worked on several things I've owned without gripe, including the AWD Talon I had which kept having leaky turbo syndrome.

 

One time I took an MJ to someone other then him, and the guy had the nerve to tell me he was going to charge more than I paid for the whole truck to fix something, after taking a month or two to even get around to looking at it. I plain and simply could tell he didn't want to work on the thing, so I said screw it and took my truck home.

[Alexia]

I rather burn a MJ to the ground than have to work on anything electrical related on them. That includes the early generation XJ models as well.

 

Did you know the ignition interlock solenoid can short out which grounds through the brake light switch which then blows the fuses for the instrument cluster, instrument cluster lights, and tail lights. But wait! Why does it blow the fuses for the lights? Because the ground path for the oil pressure gauge goes to the ignition interlock solenoid which immediately fries then causes issues for the instrument panel lights. I spent nearly sixteen hours diagnosing that damn issue. Why? Because the ignition interlock solenoid IS NOT LISTED ANYWHERE ON THE DIAGRAMS!

 

AMC era wiring is not amazing by any standards.

 

*Grumbles*

[jimoshel]

Alexia, What year ?

[armyofchuckness]

Whoa. I seem to have tapped into some rage here. This does not bode well for my AMC era MJ. 

 

I dunno, maybe it's just my mechanics. Although, even the electrical pro (and he is very good) balked at doing electrical for the MJ, and I've given him significantly tougher jobs (I thought) than this one. Glad to know there's some people out there that don't loathe MJs. Sounds like I just found three guys that don't like 'em.

[Alexia]

Alexia, What year ?

Pretty much anything pre-1997. The issue I describe occurred on a 1996. Still lots of AMC design wiring in there, but with Chrysler changes.

[armyofchuckness]

So, should I just save myself the time and shoot myself now?  :ack:  I really love my truck, and it's in really nice shape other than the electrical. Just a bummer that it's such a colossal nightmare. No wonder it was so cheap.

[Alexia]

So, should I just save myself the time and shoot myself now?  :ack:  I really love my truck, and it's in really nice shape other than the electrical. Just a bummer that it's such a colossal nightmare. No wonder it was so cheap.

Typically the interior wiring is what will be the biggest headache. Anything under the hood is generally sane, but poor grounding is typically the number one cause of weird issues.

[armyofchuckness]

Good to know. Would you recommend adding more ground straps/cables while I'm in there?

[TheDude]

You may have to explain to them that all parts from the seats forward are the same as a cherokee. That's the only part that may be confusing for them. Other than electrical that is...

[Comanche County]

I think 96' XJs are the year to have, for one reason - OBD II.  That's why I think some mechanics shy away from earlier models.  OBDI and Renix/AMC year jeeps take a little more "elbow grease" if you will, to figure out electrics, vacuum, and engine sensor diagnosis.  Personally I think the older jeeps are easier to work on, but I've never had to deal with rust buckets with corrosion issues in the wiring.

[TheDirtyJeep401]

Right now I'm going to school for being an Auto Tech, and half of the stuff they are putting on cars today, is really complicated stuff. My MJ is one of the eaisiest vehicles that I have worked on. Compared to electric steering and all this other stuff.

[Alexia]

Good to know. Would you recommend adding more ground straps/cables while I'm in there?

See #1: http://www.jeepforum.com/forum/f140/cruisers-mostly-renix-tips-1304879/

Right now I'm going to school for being an Auto Tech, and half of the stuff they are putting on cars today, is really complicated stuff. My MJ is one of the eaisiest vehicles that I have worked on. Compared to electric steering and all this other stuff.

MJs are certainly less complex and technically challenged.

[mvusse]

I think 96' XJs are the year to have, for one reason - OBD II.  That's why I think some mechanics shy away from earlier models.  OBDI and Renix/AMC year jeeps take a little more "elbow grease" if you will, to figure out electrics, vacuum, and engine sensor diagnosis.  Personally I think the older jeeps are easier to work on, but I've never had to deal with rust buckets with corrosion issues in the wiring.

 

96 was an odd year. Early 96 models have OBD II piggybacked on the old OBD I harness. It is a kludge, and the worst splice job I have seen come out of the factory. Later 1996 models use the 1997 harness.

 

 I found this out when I swapped out Sparkles (early 1996) 2wd AW4 for a late 1996 4wd AW4 out of a parts Cherokee I had acquired. I swapped in the new transmission complete with bellhousing and CPS. Then I found out the CPS used a different plug than what my harness had. Ended up using 7 extensions and two universal joints to swap it without having to drop the tansmission again.

[armyofchuckness]

 

Good to know. Would you recommend adding more ground straps/cables while I'm in there?

See #1: http://www.jeepforum.com/forum/f140/cruisers-mostly-renix-tips-1304879/

 

 Wow! That's a really great thread. Thanks so much, Alexia. :cheers:  I love how it lays everything out nice and neat. I'm pretty excited now. I may have working turn signals before Christmas after all!  :driving:

[Comanche County]

 

I think 96' XJs are the year to have, for one reason - OBD II.  That's why I think some mechanics shy away from earlier models.  OBDI and Renix/AMC year jeeps take a little more "elbow grease" if you will, to figure out electrics, vacuum, and engine sensor diagnosis.  Personally I think the older jeeps are easier to work on, but I've never had to deal with rust buckets with corrosion issues in the wiring.

 

96 was an odd year. Early 96 models have OBD II piggybacked on the old OBD I harness. It is a kludge, and the worst splice job I have seen come out of the factory. Later 1996 models use the 1997 harness.

 

 I found this out when I swapped out Sparkles (early 1996) 2wd AW4 for a late 1996 4wd AW4 out of a parts Cherokee I had acquired. I swapped in the new transmission complete with bellhousing and CPS. Then I found out the CPS used a different plug than what my harness had. Ended up using 7 extensions and two universal joints to swap it without having to drop the tansmission again.

 

I didn't know that, good to know info Mvusse. All four XJs I've owned have been 96s', but I never had a single issue with any of them that required me breaking into the harness.  Bought one near new in 97' and put almost 200K on it and only had to replace the TPS once...that's it.

[Alexia]

 

 

I think 96' XJs are the year to have, for one reason - OBD II.  That's why I think some mechanics shy away from earlier models.  OBDI and Renix/AMC year jeeps take a little more "elbow grease" if you will, to figure out electrics, vacuum, and engine sensor diagnosis.  Personally I think the older jeeps are easier to work on, but I've never had to deal with rust buckets with corrosion issues in the wiring.

 

96 was an odd year. Early 96 models have OBD II piggybacked on the old OBD I harness. It is a kludge, and the worst splice job I have seen come out of the factory. Later 1996 models use the 1997 harness.

 

 I found this out when I swapped out Sparkles (early 1996) 2wd AW4 for a late 1996 4wd AW4 out of a parts Cherokee I had acquired. I swapped in the new transmission complete with bellhousing and CPS. Then I found out the CPS used a different plug than what my harness had. Ended up using 7 extensions and two universal joints to swap it without having to drop the tansmission again.

 

 

My first Jeep was a 1996 XJ which is why I had such a varied initial experience with them. I could only get a replacement CPS from the dealership since it used a 1997 connector on a 1996 harness.

[carnuck]

I think 96' XJs are the year to have, for one reason - OBD II.  That's why I think some mechanics shy away from earlier models.  OBDI and Renix/AMC year jeeps take a little more "elbow grease" if you will, to figure out electrics, vacuum, and engine sensor diagnosis.  Personally I think the older jeeps are easier to work on, but I've never had to deal with rust buckets with corrosion issues in the wiring.

 

 

clean all your connections and spray them with contact cleaner now and avoid trouble later!

[jimoshel]

Having been trained and working most of my life as an electronic tech, communications and data processing Jeep wiring doesn't bother me to much. I've seen the times I was pulling the hair out but stuck with it and found the problem. I believe the only time I was ever stumped by a gremlin was in '74 while working at the Kwajelien Missile Range. They lost a missile 5 minutes after launch and didn't find it again until 20 seconds before splash down. It was pinned down to one of the receivers i was responsible for. Had more PhD's brain power going thru that set and they never did find out what happened.

[Pete M]

Having been trained and working most of my life as an electronic tech, communications and data processing Jeep wiring doesn't bother me to much. I've seen the times I was pulling the hair out but stuck with it and found the problem. I believe the only time I was ever stumped by a gremlin was in '74 while working at the Kwajelien Missile Range. They lost a missile 5 minutes after launch and didn't find it again until 20 seconds before splash down. It was pinned down to one of the receivers i was responsible for. Had more PhD's brain power going thru that set and they never did find out what happened.

 

covered your tracks that well, eh? :D

[jimoshel]

 

Having been trained and working most of my life as an electronic tech, communications and data processing Jeep wiring doesn't bother me to much. I've seen the times I was pulling the hair out but stuck with it and found the problem. I believe the only time I was ever stumped by a gremlin was in '74 while working at the Kwajelien Missile Range. They lost a missile 5 minutes after launch and didn't find it again until 20 seconds before splash down. It was pinned down to one of the receivers i was responsible for. Had more PhD's brain power going thru that set and they never did find out what happened.

 

covered your tracks that well, eh? :D

LOL

 

Got interrupted for supper before I finished but the point of that diatribe was 'Sh*t happens."

[92tanMJ]

I rather burn a MJ to the ground than have to work on anything electrical related on them. That includes the early generation XJ models as well.

 

Did you know the ignition interlock solenoid can short out which grounds through the brake light switch which then blows the fuses for the instrument cluster, instrument cluster lights, and tail lights. But wait! Why does it blow the fuses for the lights? Because the ground path for the oil pressure gauge goes to the ignition interlock solenoid which immediately fries then causes issues for the instrument panel lights. I spent nearly sixteen hours diagnosing that damn issue. Why? Because the ignition interlock solenoid IS NOT LISTED ANYWHERE ON THE DIAGRAMS!

 

AMC era wiring is not amazing by any standards.

 

*Grumbles*

I wonder if this is my ignition was smoking a few weeks back :hmm:

[huck731]

I've never had issues with mechanics not wanting to work on my jeep but maybe thats because 1.) I already know the issue and they just have to fix it, and most likely the main reason 2.) My MJ mechanic drives an MJ.

[Oyaji]

Not an issue for me.

.

I don't use mechanics - never have,  and (God willing and as long as I keep my health) I never will.