Jeep Needs a Neutral Safety Switch

Oh I love it.

After hitting a deer, doing the spark plugs, fixing a coolant leak and the suspension, the neutral safety switch goes on the jeep. Of course it’s not an easy fix, I was really hoping it was the starter relay. I was at autozone at 8am this morning buying a new relay and they sold me the wrong one (for $6 I am not even going to bother returning it) and then when I got to wawa to fix the jeep it passed the voltage test on the battery, which was the other quick fix I was hoping for. I ended up opening the engine electrical panel to see it was corroded as hell, so that’s another fun possibility but I was able to swap the relays from the fuel system to the ignition system and I still couldn’t get the starter to move. I considered jumping the battery to the starter but could I replace the starter in the wawa parking lot? Nope. I figured it was easier to call AAA and get it towed home.

The neutral safety switch on a jeep is a piece of work. Rather than KISS it together with a contact which is made when you’re in the proper gear (Toyota) on the shifter itself, Chrysler saw fit to put a gear in the shifter which moves a linkage which sweeps a rotor to the proper set of contacts. Of course the gear gets worn out, or the rotor wears down, or the contacts get corroded because the car is a rust bucket and you really start to question your sanity for trusting automatic transmissions or Chrysler to build anything right. Replacing it involves not only getting the part for $400 but then dicking with it endlessly to ensure the contacts line up and the travel is correct. Apparently there’s a third party one for $120 which “doesn’t require alignment!” but I’m guessing it simply feeds the correct signal to the harness rather than doing any real work.

After putting all the various relays and wires back into the correct positions, I started googling and found out that this affects the entire line of jeeps from 1991 to 1998. It’s a known problem.

Thankfully, someone helpfully posted the neutral safety switch schematic to the internet. While they didn’t tell you that the diagnostic port for this is next to the oil filter, you’re pretty much led to look there. The insinuation is to jumper the pins and forget about it. Now the bad part – unlike real service manuals which indicate the binary “connected”, “do not connect” and “doesn’t care”, I don’t see any “do not connects” marked in that diagram. Anyone know if it’s bad to leave this jumpered?

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A Note About The Jeep

Just a note if you happen to own a 1981 to 1995 Jeep with the inline 6 engine.

Your spark plugs are gapped at .035″ and are single anode. Do not use double anode.

However, they will work gapped to .045″, and the dead one was gapped to a frightening .051″.

Don’t trade your jeep for the world, and it will run forever for you.

Class 3 Hitch

I got this hitch from the junkyard for $20. If you want to talk about recycling, this is the ultimate form of it. Their jeep dies so I pick up the parts for a song and they live on vicariously through my own jeep. It helps that they’re cheap because they require little processing other than you getting under the car and unbolting them yourself.

On ebay, the hitches go for about $100 + $20. They usually don’t include the installation kit. The reason for this is because the installation kits, unlike the hitches, are vehicle specific since each rail is different. Jeeps themselves have either “tube rails” (round) or “square rails” (standard box-frame). And no-drill is a misnomer, I guarantee you will find the holes need to be bored.

I pull this thing out of the yard and the first thing I notice is that the exhaust system for the jeep I pulled it off of is different from my own jeep. This isn’t a huge issue since I have the tools to drill holes in steel. Nevermind that the exhaust system on my jeep is held on with a brass coathanger – one too many offroading accidents. It’s going to need two holes drilled through the plate to ensure that the exhaust system still bolts up. Then there’s the problem that I didn’t realize I needed to grab the nuts out of the other rail also. I needed an installation kit.

The hidden hitch website doesn’t have a phone number, but they do have a contact form. I submitted it asking for a phone number to call and discuss buying an installation kit and they got back to me promptly. They indicated they didn’t sell directly, but they did give me the number to call a distributor/installer. I called them and spoke to a rep. $56 for the bolts to install this thing. I asked them if I could just buy the missing bolts, they said no. They also said they needed to inspect it if I installed it myself for the safety sticker – the inspection is another $20. This is bullshit, there’s no “hitch inspection” law in PA. But, once they start bullshitting, it’s pretty much time to make up your own plan.

I checked the bolts, they were crusted in crap which is typical of junkyard bolts. Once I took a wire brush and got some of the crap off it revealed a number and a symbol. The number is the bolt strength rating. This is a goldmine right here since we instantly know which bolt we need (in my case: #6). The symbol is the bolt manufacturer and happens to be Delta. Now that I know this, I also know that the bolts require 75ft/lbs of torque and I know which bolts and nuts I need to assemble the hitch safely. Instead of paying $50 + $20 “inspection”, I can go to MR2 Home Depot and find something that matches. Actually, two somethings, six washers and a bucket of lock-tight. Some jeeps have captive nuts welded into the frame to accept a hitch or skid plate, mine have to be fished into the holes.

How are we going to do that? Bolts are steel. Steel is magnetic. Magnet-on-a-stick to the rescue. MoaS is a simple device consisting of a magnet mounted on a telescoping stick. You drop the bolts into the assembly hole of the frame rail (there’s one hole much wider than the others, sometimes it’s a push in from the bottom) and then you drag the bolts to whereever you need them to poke out of the rail. What if you don’t have a MoaS? Either buy one (they’re cheap), make one, or use fishing wire (the most frustrating method). The fishing wire thing sucks because if there’s any obstruction in the rail, the bolt will get caught up on it. The magnet works so well because you can put it on the sides of the rail and that’s where the bolt goes to pull it around dirt.

So why all the trouble? Bike racks, cargo carriers and grills! No, seriously, towing the MR2 requires a class 3 hitch, u-haul trailers require a full hitch and you don’t have to pay the per-miles fee nor the gasoline, and it’s generally a good thing to have if you need to attach things to your car.