no start - no power situation

[fuzzydog]

hey all, haven't been on here in quite a while as my xj has just been rocking along great. It is a 1990 with 4l and AW4 auto. Heavily modded running gear but engine managemetn is pretty much stock. I am running a 2 battery system with both batteries in parallel with no isolator (for now). hey, it's only temporary until it becomes permanent, right? :rof:

Last time I drove it was about a month ago, came home and parked it. Went to start it yesterday and nothing happens when I turn the key - as in no clicks, whirrs, pops or anything.
battery voltage is good and I even topped them up on the charger. With the key off, I have power locks, headlights and dome lights. That is it for electrical accessories.
Key on, I have nothing more - no wipers, no blower motor.
My dual electric fans are wired directly to the battery through relays and I have manual switches inside - they work fine and strong.
I have the starter relay by the battery and I put 12v to the starter wire and got cranking so the starter solenoid and starter motor are not suspect.
So probably the NSS or ignition switch - any thoughts on which one would interrupt power to accessories as well as the starter? Seems to me the NSS would only concern itself with the actual starting circuit and shouldn't affect wipers and blower motor?
leads me to suspect the ignition switch more.
Just tossing it out there for any ideas before I really dig into it tomm night.

 

[Overland]

Look to see that the rod in the column is engaging the switch. Does the steering unlock?

 

[fuzzydog]

good thought - the steering does unlock and I can hear the rod moving in the column. maybe it has become disengaged from the ign switch? that's the first thing I will check tomm.

 

[Ecomike]

Pretty sure you nailed it, a bad ignition switch, common on the Renix jeeps.

 

[fuzzydog]

Ok definitely looks like the ign switch. That sucker is dirt cheap at rockauto but.....I think it is time to ditch it altogether. I am just going to wire in a master powr switch and a push button for start.

 

[fuzzydog]

Just want to update this thread and give the renix gurus a puzzle. I never did resolve this until today, and even then it is a hack fix.
There aprctually is nothing wrong with the ignition switch.

I traced wires through the bulkhead connector and cavity d4 is supposed to have battery power but it doesn't. According to the fsm for 1989 (my xj is is a 1990- should be identical) the d4 cavity goes back directly to the starter solenoid by the battery where it shares a ring terminal with another wire - both wires have fusible links, one orange and theother green. There is only 1 ring terminal at my starter solenoid with both a green and orange link. Both links test good and the wire I suspect goes to d4 shows 12v at the starter relay, but not at the bulkhead connector. All the other 10 GA wires and fusible links at the starter relay test good.
According to the wiring g diagrams the d4 wire runs directly from the starter relay to bulkhead connector through the harness, which is in a plastic loom as well. I simply can't see how that wire could have spontaneously broken inside the harness but it seems that is what happened.
I ran a wire from the starter relay and spliced it to the suspect wire just before the bulkhead connector and everything works as it should. I am glad it is working but it bugs me that I still don't really know what caused the problem.
Any thoughts?

 

[Ecomike]

Ask cruiser54 and 8Mud to chime in here, they are the gurus on that wiring.

 

[8Mud]

Not all that uncommon for the copper core inside a wire to vibration fatigue under the insulation. The copper core fatigues (cracks) almost all the way through, then starts to melt from the increased resistance.

I haven't seen it in the chassis wiring. More common in the fuel rail to firewall harness (actually a TSB about this). It can be a pain to find, most times I felt it with my finger tips while squeezing the wire between my fingers every half inch or less the entire length of the wire. Sometimes there is a slight discoloration or stiffness in the insulation.

Or there is a spice in that cable not shown on the diagram.

There was a thread awhile back about the difference between the 87, 88, 89 and 90 harnesses.

If you bypassed the fusible link, think about putting an inline fuse near the starter relay power junction stud. Unfused wiring causes fires.

To test those fusible links you have to remove them from the stud and test them isolated. Possible to get a false reading with them connected to the stud.

 

[fuzzydog]

Lol! From one extreme to the other. Earlier this year it wouldn't start. Last night at 230 I hear a noise outide and it is my jeep cranking the engine over. At first I thought it was someone trying to steaL it but I removed one of the rear tires just to prevent that.
Nobody inside, key off and it it's just cranking and cranking. Headlights are on, and there it's smoke and a bit of fire coming out from behind the passenger headlight. Scrambled to pop the hod open and disconnect the 2 batteries which I got done just as they ran out of juice. Got the little bit of fire put out and back to bed. Won't have a chance to look at it until Saturday in the daylight but I suspect it might just be time to take alll the goodies off and sell them. If it had a harness fire I don't think it is worth the time to repair that. Very odd that it would spontaneously start though. It has been parked there with the Batts connected for about 2 weeks now. And no this jeep definitely does not and never had about remote starter.

 

[blu3fan]

Ouch. that sucks dude.

 

[90xj06]

i would start by apologizing to what ever god you upset

 

[Ecomike]

i would start by apologizing to what ever god you upset

Or kick his arse and shove him back in the jennie bottle he came out of and make him fix the jeep, LOL.

Sounds like the wiring at the ignition switch went bad and started the jeep/ short.

 

[fuzzydog]

Could be the Jeep gods were offended as I have hardly driven the xj in the past couple years. Seems the 2000 wj in the driveway is getting all the use and loving these days.....