Weird electrons flowing- 95 D1- Disco gurus- need some help...

[skrufy]

:ack: '95 Discovery, 4.0l replacement engine, 130k vehicle miles......

Gents/ladies- Am home for about an hour- camping all week w/ kids, out the door again quick after resupply......

Don't even know how to ask the search engine to start re-searching this problem- have both the Shop and Electrics Manuals in my jeep to head back out into the boonies- will read them tonight and hope to find some answers to this one....(- relax: the jeep is my restored 1952 Willys Army M38A1 w/ matching 1951 1/4ton M100 trailer- this is what my 8 & 11yr old sons wanted to take camping.....)

I am usually pretty good at fixing stuff, but already this one might be beyond me... Last night my wife brought the Disco home after having the following symptoms- (which happened to me once about 6 months ago and never re-occurred- we(local garage and me..) were in the midst of swapping out a blown up 3.9 for the 4.0 and had numerous other issues to get it to run right, and had assume this problem was resolved).... while driving, the vehicle lost electrical power to the auxiallary/secondary? circuits: no lights, no windows, no wipers, radio alarm went to flashing red LED like it does when vehicle shut off and locked for the night.... the vehicle runs okay- BUT when placing the shift lever (auto trans)from drive to N to R to Park- the gears grind slightly- - sounds like hitting the starter and engaging it when the engine is already running, and the resulting clash of the starter teeth against the ring gear..)- so Drive to Rev thru N = gear grind, or D or R into park = gear grind..... she worked the lever back forth slightly and finally got into Park, shut it off.....

Started it up a few minutes ago- no apparent problem- for now...?

So- some sort of lock out solenoid, other component failing here? what is going to cause electric failure like the vehicle is shut off, but allow the Disco to drive down the road?

Hopefully, someone out there can answer to let me get this fixed ASAP, and I apoligize is this has been/probably has been covered, but no time/don't know where to search.

As usual, thanks for all the great info that is so generously shared in this forum-

rock on.....

Tim
Alpine, Az

 

[AfiRover]

Check the switch on the back of the ignition first, then look to the fusebox under the bonnet.

PT

 

[RVRSRVC]

A loss of much of the ignition-on components, but no interruption of engine running? And a starter motor engagement when moving the shift lever through "N"? Good one! I'd second the ignition switch to start- no pun intended. Lets say the switch is getting wonky, it could be in the Start mode all of the time, but when you pass through N it closes the Park/Nuetral safety switch and fires the starter motor.
I see 6 wires on the back of the switch- white is ignition fed stuff, white with red is start, but what does white with blue head off to? I

 

[skrufy]

Guys-

thanks for the replies and info.... just got off the phone with Keith, one of the great guys at British Pacific...... he suggested checking the Neutral Safety Switch/Inhibitor Switch on the side of the bellhousing (RTC 4937 $159.00...)- simple solenoid type switch held on w/ one bolt/one electrical connector- remove /clean with electrical contact cleaner/ brakeclean/WD40 the shift linkage area as needed, etc..... and since I have replaced the turn signal/hi-lo beam switch not too long ago, remove the steering column housing again and check to see if all the wires/plugs are firmly in place/ clean w/ electric contact cleaner.... the electric only portion (STC1746 $109.00) of the ignition sw/ key/lock assembly is available vs the price of a entirely new ignition/key lock assembly ($596.00)

there are at least 2 other relays at about $8.00 each that could be associated in this mess: the yellow YWB 10027L, or the black or green YWB10032L

I don't like to shotgun fix things w/o figuring out the real problem......

I will start out w/ the Inhibitor Switch to see if that could be the culprit.....

There is a reason why they sell the Black T-Shirts over in the Uk that say: "LUCAS- Prince of Darkness..."

Ya gotta love these things- otherwise they'd make good boat anchors.....

Tim :banghead:

 

[ptschram]

Well, we could go about throwing parts at the truck, or we could get out the trusty ETM and find out what's happening...

FWIW, it could also be alarm related. The '95s are known for water ingress through the cowl and corrosion causing problems with the alarm.

 

[skrufy]

Posted an update earlier today- but who knows where it went???

P.T.- thanks for the reply..... I assume ETM stands for Electrical Test Meter? if not, please let me know as I am drawing a blank otherwise......

In a nutshell of my earlier/vaporized update....

removed/cleaned the Inhibit/Neutral Safety Switch- the plunger moved easily, no dirt, etc, seems to function ok.... did not disconnect the elec. connector- hard to reach, and was tie-wrapped together by the last mechanic......

removed steering column housing- found nothing loose or out of place.....

So, am basically back at square one trying to figure out a very intermittent problem..... PT or anybody else have any other ideas..... this Disco has been a dry Arizona vehicle virtually from Day 1, so I don't have any usual corrosion problems that perhaps are more common in the eastern USA with salted winter roads, etc..... PT, where to start with the ETM?

thanks for any thoughts on this one......

Tim

 

[ptschram]

ETM is electrical troubleshooting manual.

When investigating these problems, merely looking at the ignitions witch isn't enough, you must move the staked on piece to see if it is moving independently of the pieces inside.

Neutral safety switches rarely ever go bad.

As for where to start... When it isn't doing what you want it to do, start at the battery and work your way to the circuit that isn't doing what you want it to do.

There is a reason these issues are often expensive to fix.

PT

 

[skrufy]

PT-

again, thank you for the reply...... my update last night was an abbreviated note of what I looked at and added in my post that vanished somewhere- we had an electrical storm and it's not unusual in our remote area for the DSL line to go down.....

after loosening the two tiny set screws on the ignition switch, I removed it and found an enclosed switch that moves/changes the switch position and internal contacts as the key/lock shaft moves from off/position 1/run/start, etc...... the halves of the switch snap together, but I did not force it open past the locking tabs because I didn't know what springs/plates/ball bearings/ etc might fly out of it, and it was just starting to rain harder, so I buttoned things back up quickly.....

Can this switch be disassembled for inspection/cleaning? is it generally a long life device or something to plan on replacing due to normal wear/tear?.....

I do have the LR Electrics Manual and the Shop Manual for my '95 Disco 1..... electrical spark chasing is not my favorite thing to do, but can do it to a limited degree when I have to....... both manuals assume you are factory trained and have the Test Book...

as for circuits, which do you suggest as a starting point from the battery? of course, it would be nice to have a failed condition to trouble shoot from vs an intermittent one that has only happened twice months apart..... our area is remote/in the mountains- would like to get this fixed obviously...... and yes, stuff like this can be $$$/lots of shop time and some folks don't/won't understand.....

BTW- no OBD failure codes

speaking of throwing enough parts at it to fix it: years ago I flew demo Learjets for the Factory in Tucson- had an engine roll back on a new Lear35 on final approach into Dallas-Love Field one night- dropped off the potential customers for their meeting/dinner, etc- 6 hour window, zipped up to the other factory in Wichita, mechanics trouble shot the problem, fixed?, I was a qualified test guy so I did all the engine run ups on the ground- max/min temps/ oil pres/ accel times w/ a stop watch, etc, airborne tests at 30k and 40k feet enroute back to Dallas, all was to spec per engineering standards, I signed off on all those tests that I did on a routine basis, all records to be kept forever per FAA in a saltdome storage bunker underground somewhere in Texas or Kansas- all is well in the Land of Oz...... engine rolls back again on final into LUV- the new $35,000 engine fuel control module, plus jet time- engine/airframe, fuel, mechanics, etc was not the problem!! don't know what the final fix was on that jet, as I had to leave early the next morning via commercial air and never flew that one again......:banghead:

thanks for all the help!

Tim

 

[ptschram]

Your Disco is much like the general aviation aircraft I worked on in College!

You will not need the testbook for this, you're gonna have to do brute force troubleshooting.

The switch does not snap apart, if it is at all loose, that's probably your culprit.

After never seeing such a thing, I replaced two in a week two years ago!

 

[Yadranco]

You live in the mountains ? Do you have mountain dew in the mornings sometimes when air is humid ? Here is your problem even if truck is from Arizona . Same thing happens to my 94 d1 . Suddenly nothing worked . I would press brake pedal and rear wipers would start to work . Turn out to be ground problem . Check all ground straps conections .

Particularly clean and put some dialectic grease on ground strap near capacitor in engine bay , every electric conection you inspect , clean it and add some dielectic grease . I agree with PT , you don't have to invest lot of money to fix this problem . Just time and one tube of dielectic grease.

 

[skrufy]

Again- thanks for all the replies and suggestions- this forum is great, tons of experience readily shared all around....

PT- the switch is not loose, as in no rattles when shaken, not that there is enough wire(s) length to give it a healthy "Ford" test.....

Not much dew here Yadranco in eastern Az. at 8000ft.- it is the monsoon season here, typical afternoon rains/thunderstorm that clears by late evening, but still not much/any dew.. we get about half of our annual rainfall of about 24 inches this time of year..... I will follow your suggestion of checking the grounding straps, wire brushing straps/frame, healthy coat of dia. grease....

As for the rest, I guess I'll have to do some healthy troubleshooting- I was afraid that it might have to come to that, hence my questions to all you smart guys who might have an easy quick fix- "oh yea, that indicates you have a bad Weird Electron Control Relay, and it's cheap at $279..."

More Speaking of weird electrons: we had an F16A Block 15 - the original all ElectricJet- in Tucson at the F16 Schoolhouse for all ANG and most international training... one day give a student, with maybe 8-10 hours in the jet, had an uncontrolled/unasked for nose pitch up- instant 40-50 nose high- out in a practice area at about 15,000ft.... the kid continues the nose pitch into a loop, then they call all the world, phone patches to the factory experts, to figure this out- nobody knows, return to base, burn down fuel, fly a straight in approach and land.... well, they -student and his IP- Instructor Pilot also flying solo in his own jet, do just that..... student is on short final, maybe 2 miles out @ 600ft, the nose pitches up again, IP commands the student to "Eject,eject,eject" - commands this about 3 times..... student has his hands full- doesn't hear this- only the F16 could do this from so slow/behind the power curve- the kid plugs in the afterburner, gets the gear up- they go back out, settle down, come back in, approach and land...... that jet was dissected by all the engineers/experts for about 3 months to find out what/why?- they finally blamed it on the stick grip which has about 10 switches on it/half mile of wire in it- although the grip tested a-ok on it's own bench tester..... the jet never had another problem that I am aware of...

Will let everybody know what I find- may be a while as this is a remote/very intermittent problem- let's hope it's not in the middle of a snow storm at midnight the next time....

If anybody else has some ideas- please chime in.....

Tim
Alpine, Az.

 

[ptschram]

I'm glad the biggest airplane I worked on was a Comanche!

DO NOT USE DIELECTRIC GREASE ON YOUR GROUNDS!

This is important, I'll repeat it. DO NOT USE DIELECTRIC GREASE ON GROUNDS!

Dielectric grease, by definition, is an insulator. We want a conductor at these points. Use either copper or aluminium anti-seize for this application. It will prevent corrosion and improve conductivity.

Good luck,
PT

 

[NJROVER]

I'm glad the biggest airplane I worked on was a Comanche!

DO NOT USE DIELECTRIC GREASE ON YOUR GROUNDS!

This is important, I'll repeat it. DO NOT USE DIELECTRIC GREASE ON GROUNDS!

Dielectric grease, by definition, is an insulator. We want a conductor at these points. Use either copper or aluminium anti-seize for this application. It will prevent corrosion and improve conductivity.

Good luck,
PT

WOW I thought I was the only person who used copper anti-seize on connections.

As for the issue at hand I would start checking all the power and ground wires going from the battery to the fuse panel under the hold and on to the one inside the car. It is a intermitent issue so I am assuming that maybe a wire may have a cracked insulator and water go in it at one time and the wire has crosion in it and maybe this issue happen after suspencion flex or hitting a bump of such in the road disturbing the corrosion in the wire and causing your issue

 

[Quentin]

Ditto on the "Copper Slip" as we call it here..... Best stuff invented :applause:
I use it liberally wherever I can.....
Sorry, no real input on your little gremlin problem, just spend the time and I'm sure you'll find the problem......

 

[skrufy]

All-

good point on the diaelectric grease- never thought about it that way, but it sure makes sense.....

I have a can of silver grease- which I think means aluminum- Permatex AntiCease (sp?) compound- which I think might do the trick- any thoughts on this product.?....

I will check all the ground straps- I do remember the mechanic doing the engine swap saying he had problems with the electrics- he forgot a ground strap, and that cleared it up.....( FWI, my 3.9 grenaded one night- threw 2 rods- we found a used/guaranteed 3.9 in PHX with about 85kmiles on it for $1500- all is well until a 4.0 shows up- so it wasn't a swap drop in, all the intake, etc had to be swapped- but that is a story-long one- for another time......)

Will post my findings...... thanks again.....

Tim

 

[ptschram]

My money is still on the alarm unit interfering with the ground for the neutral start circuit.

 

[skrufy]

Thanks PT-

will check all the vehicle grounds I can find- off engine to frame, batt to frame, etc clean and then slather w/ anti-cease.....

then I will drag out the Electrics Manual and start with the alarm circuit- not my forte, but w/ a beer, nothing is impossible.....

( my dates are most likely in error, but one of the main reasons why the 3rd voyage of Sir Martin Frobisher- with 25 ships and 750+ men failed in May of 1625? to establish an English settlement on Baffin Island- west of Greenland- besides sailing a month too early = ships getting crushed in the ice of what is now Frobisher Bay, the Captain of the ship hauling all the beer got separated from the rest of the fleet in the fog, by now probably 2-3 smaller groups of ships. he sees all the ice and debris from other ships- says the "Hell with it" sets sail and goes back home to England. Expedition fails- Survivors follow suit, investors go broke..... True story...):smilelol:

will advise w/ what I find..... thanks again-

Tim atriot:

 

[ptschram]

Tim:
I am not saying that you have a ba ground. I suspect the circuit board of your alarm unit has become corroded and the ground circuit through the alarm is not continuous.

Humor me and take a look at your ETM and test the circuit to the starter relay. I suspect you might find the ground side of that relay does not go to ground as there may be a break somewhere inside the alarm box.