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Discussion Starter #1
Ok guys this one has me overwhelmed, I will describe it the best I can.

This problem only comes up when the air temp is under 40 degrees F, at that point it will take a second for my system to energize, at 0 degrees F it will take a couple minutes to energize. The truck runs great when its warm outside.

When I turn the key to the run position, the lights on my instrument cluster do the normal cycle when warm outside, the maint reqd and CEL come on, then go out and the truck starts and runs normal. When the temps drop, I turn the key on and it takes from a few seconds to a few minutes for the maint light to start to illuminate along with a drum-roll speed clicking from my ASD relay. The maint required light flickers at the same speed as the relay click. Eventually the relay stops clicking(and maint light stops flickering), my CEL illuminates for the test circuit and goes out normally at that time along with the maint light.. and the truck will start and run at that point. If I try to start it before the light cycles complete when key turned on I have a no spark condition(and probably not fuel pump). It will start once the lights go out. It runs great immediately when warm out, it will sputter and miss and die when cold out a couple times until it finally fully gets the juices flowing(it will miss pretty bad for a few seconds) and it will run decent from that point on, but still not as good as when its warm outside.

Te vehicle usually doesnt stall when running, but did stall once on the freeway after driving 2 hours the other day, but it did restart about 15 seconds after.

Its obvious I have an electrical issue somewhere. I have made some recent electrical repairs including the ignition switch, and many repairs to the main engine harness at the relay box under the hood going from the bumper to the firewall on the drivers fender. The grounds in the harness were melted and i replaced or repaired all wires that were effected by it. The trucks performance did improve and runs great if its over 40 degrees. I looked pretty hard and fairly certain the meltdown did not go beyond the area I repaired.

I havent got any codes except a 14 when I tried to start the truck before the light cycle which is a map sensor code. The map sensor is reading 4.56V on the supply side and seems to be reading in the right range when the vehicle is running according to the info I looked up. The truck since has not given new codes or the 14(MAP sensor).

The issue seems obvious to me its in the ASD relay circuit with the relay clicking away when i turn the key on until the circuit finaly energizes. I cant find a manual locally with a reasonable diagram, or a wiring diagram online to see whats in this circuit to narrow my search of endless wire harnesses which isnt helping the cause.

I have a serious squirrel issue here.. little suckers are like gremlins(I swear its a conspiracy).. they have a tendency to sabotage my vehicles at random intervals. They chewed the wire harness and plug at my fuel pump and the vent line about a month ago(tried to blow me up?), and there were acorns left in a little pocket behind the wire harness under my relay box to they are a suspect in that meltdown too... It could be possible one of these previous repairs have an intermittent connection causing the problem?

Any suggestions or shortcuts I can take to narrow down my search would be greatly appreciated. Even if it comes down to my ECM being damaged it will be dealt with, but not until im certain the circuits are working properly... but id hate to replace the ECM to soon find out I had a bad ground by the VSS or something stupid that was the entire issue.


Happy Holidays guys.
 

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Discussion Starter #3
Thank you for the link to the factory service manual.. it would be ideal to have it in my hands right now and I surely will pick it up in the near future, but Im really hoping I might be able to resolve this issue before the manual could get here via mail. Wishful thinking at the least..

Im not looking for anyone to hold my hand through this, I was just hoping someone knowledgable might be able to tell me what is likely on that circuit, what some common suspects might be, etc .. an immediate $102 manual would put a dent in the already exhausted xmas and 2 kids birthday budget lol.

This truck is a daily driver and I cant afford to have it go down for long, and in all honesty I think this is likey a simple inexpensive fix like a broken wire or ground. Im not looking for the magical psychic answer, but suggestions towards components to look at would sure help possibly narrow down the search.
 

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Relays usually 'chatter' with insufficiant actuator coil hold-down voltage (dropping below, say ~8 volts). A high resistance in the 12 volt key-on ignition supply circuit or the PCM ground to body circuits would be the first places that I would look. The negative side of the relay actuator coil and probably the 'ck eng' and maint req'd' warning lights are grounded through the PCM. Grounds should generally be less than 0.3 volts to the battery negative post.
It is the PCM that should click the relay on once at startup and off once at shutdown as it is needed.
The wire colors and this portion of the electrical diagram may be very similar to the V6 and V8 models across most EFI years and may be helpful to you, although the 1994 Ram 1500-3500 factory service manual coverage would be best.
If you suspect an internal PCM problem, try heating just the PCM itself with a hair dryer and see if the problem goes away? Heat can also be directed at other components until one makes a difference in behavior.
 

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Discussion Starter #5
I will absolutely check those out 1st tomorrow right after coffee and hopefully the temp hovers close to a balmy 15 degrees by that time.

Not having a garage and wearing enough clothes to survive the north pole doesnt help the cause or try to fit your arms into tight places... This is one of those want to find it and get it done asap jobs.
 

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This problem may very well be related to the animal chewing or the melted wiring or previous wiring repairs that you found. A body ground may look good and tight, but sometimes loosening and retightening a terminal bolt will re-establish a good contact because of unseen paint or corrosion under the bolt head or thread-to-body contact. A lot can happen in 19 years.
Mating connector terminals and splices can be the weak link (high resistance) in a circuit, but wire breaks, pinches and rub-throughs may occur along the harness itself. The problem doesn't sound like an open or shorted wire, but something in between.
There seems to be a temperature dependent, high resistance somewhere in the power and ground circuits. This has to be either found or ruled out before condemning any components. The circuitry between the fuse/relay distribution box-to-firewall, firewall-to-steering column and back to the distribution box. Then the distribution box-to-PCM and back. The PCM may have 2 or 3 discrete grounds distributed to the body sheetmetal around the inner fender/firewall.
Measure voltages to ground while it is acting up. Keep a battery charger on low to keep the battery up while the ignition key is on.
Because it is so consistently temperature dependent, makes me concerned that the problem may be inside the PCM. Sometimes solid state devices will fail in this manner, but a true diagnosis has to rule out everything external supporting the PCM first.
I used a 100 watt bulb in a work light for a hand warmer. Sometimes you can't do everything with gloves on. These new florescent work lights don't give off any heat, but are easier on the eyes in a dark garage. Do this search in an orderly one-thing-at-a-time approach, bring your coffee with you and do take frequent breaks to think things through along the way.
You may find some useful wiring diagrams online. I could not find an exact match, but even the Dodge/Chrysler/Plymouth cars and Jeeps used the 'corporate' same wire colors and the same general circuit layout. Beware of some older/newer circuit differences that could throw you off the track. The Cummins diesel truck wiring is a fairly different animal than the gasoline truck.
 

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Bad battery or its connections?
 

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Discussion Starter #8
The battery is a month old and I had it retested, its a very good battery. I replaced the positive battery cable going to th relay box, and also the negative battery cable within the last week. I am very adamant about cleaning connections wen im doing this. Ive gone through and checked all the sensor and wire harness connections I come across to be sure they are clean and add a little fresh dielectric grease.

I did replace and repair a lot of wires in the harness under the relay box where the short was.. anything that looked like there was moderate heat damge, but its alot of wires and theres no gaurantee I didnt miss something. The grounds in the harness took the most damage and were all pretty much replaced. When wires in a harness are put to that much heat nothing will suprise me and theres going to be unseen damage too.. Heck any of them could have got exposed to enough heat to start internal wire damage. I should have replaced them all now that I think about it*.

The truck is at the age the plastic wire harness cover is brittle anywhere in the engine compartment which leaves risk for exposure anywhere and everywhere. ( I have replaced some and will replace all in the near future)

I actually found good wiring diagram at th autozone website of all places ... Only problem is it dosnt show where any of the grounds are. I have found a series of grounds near the relay box that go to the fender wall, one of them has 3 wires going into a flat square plactic box that connects to the tab that gets screwed to the fenderwall? Thos wires seem in tact but did get very hot in the short. There are 2 other light grounds that get grounded near it with different screws. There is a body ground at the battery, a body ground on the front bumper(wrecker push bumper), 2 ground straps connecting to the rear of the cyl heads going to the firewall, and 1 heavier ground that im not sure where it goes anchored on a support bracket near the thermostat housing... This is all I found before getting pulled away for a family emergency but obviously the search will continue.

After im done finding and reconnecting all the component grounds and doublechecking the burnt harness repair.. Theres a Dark Green and Orange wire that seems to power most everything on that circuit and ill start to probe that to see if i can find a break or too much resistence.. gotta start somewhere right?

It would be a whole lot easier if a good chunk of these wires werent tucked in near the fuel rail, under the air cleaner intake and plenum, and surgically threaded into the most inconvienient places.

Sorry for the long winded detailed response, but hopefully the resolve of this might help someone else some day because this is a nightmare to diagnose! lol
 

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This seems like a bad short-circuit that is not tripping a protection device. What made the ground wires melt initially?
 

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Discussion Starter #10
Bob Lincoln said:
This seems like a bad short-circuit that is not tripping a protection device. What made the ground wires melt initially?
Im 96% certain it was a squirrel, the little gremlins left some acorns behind. I didnt find anything noticably fried besides wiring. The grounds that run in the harness from the firewall to the bumper were severely cooked, the insulation was 100% gone on a couple. It wasnt obvious what was the primary hot source of the short.

The ground in the harness near the firewall is a heavy guage ground that splices off to several small diameter grounds in the harness it appears the meltdown stopped where the large diameter wire splices to small. Come to think of it i havent checked to see where that large ground wire comes from, there could be damage at the source... Not positive but I think it comes from inside the cab.

Tomorrow it looks like I have some free time to get back under the hood pending no more unforseen family disasters.
 

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Check Grounds with a good wiring diagram for Ram. Sounds as if a ground is not off,but bad High resistence.

Do careful v drop checks with a DVOM! Its long tedious but may well find your trouble. Theres damage in

harness somewheree you have not found!

Jake
 

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Discussion Starter #12
Well I redisected the wire harness at the relay box where there was major damage and everything there checks out good(relay box area) includng the pre-exiting wires. I checked every connection from the relay box to the connectiors at the firewall and everything checked out as it should. I have no idea if the problem is before or after the PCM... all I know right now is i have a whole lotta wires that are good according to the ohm meter, 1 had questionable resistence so I replaced the wire.. no help.

Im at the point of going component to component to see if theres a voltage drop. I will replace the main positive wire from the relay box to the alternator and any related splice components in the near future just to say I did. i dont think its going to cure it, but its one of the easiest to eliminate right now and my voltage guage when running now is reading a little higher than it used to (14.8 vs 14.1) which is telling me something is funny somewhere.

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?pageId=0900c1528007154c figure 31 has the majority
 

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The Lt Gn/Bk wire is the 12 volt ign/start feed that needs to be monitored while the ASD relay is clicking. Note that the fuel pump relay coil is also in parallel with the ASD coil.
The Dk Bu/Yl wire is the return wire that should be under 2 volts when the PCM (pin #51) is grounding the relays.
You can shove the end of a bent paper clip into the relay female terminals and then push the relay in on top of them for use as test points to be right at the relay terminals.
Dk Gn/Or at PCM pin # 57 needs to be the 12 volt ign in.
Rd/Wt at PCM pin #3 needs to be 12 volt battery in.
Bk/Tn at PCM pin #11 and #12 needs to be a ground with 0.3 volts or less to the battery (-) post. It is good to measure all voltages to the battery posts because a connection may still be good from the point of test to body or frame, but have a high resistance from body to battery. You don't need misleading tests.
There was a recall #875 for the ign switch and wiring because of high blower current that could cause electrical damage. An underdash relay and wiring overlay was added as a fix. Make sure that this recall has been been done and done properly. Possible ign switch damage could be a result from overcurrent. Any burnt wires, melted connectors or ign switch here could be a clue.
http://www.nhtsa.gov/About+NHTSA/Press+Releases/2000/ci.NHTSA+Publishes+List+of+May+2000+Recalls.print
 

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Discussion Starter #14
ImperialCrown said:
There was a recall #875 for the ign switch and wiring because of high blower current that could cause electrical damage. An underdash relay and wiring overlay was added as a fix. Make sure that this recall has been been done and done properly. Possible ign switch damage could be a result from overcurrent. Any burnt wires, melted connectors or ign switch here could be a clue.
http://www.nhtsa.gov/About+NHTSA/Press+Releases/2000/ci.NHTSA+Publishes+List+of+May+2000+Recalls.print
I had that recall work done about a month ago, I learned of the recall the day I had to replace my ignition switch when the truck didnt want to turn over... They goofed up a little somewhere because my drink holder wouldnt open all the way since, I dont want moving parts catching the new wiring they put in. This truck also had a headlight switch and hood release recall.

Ignition switch and the bypass relay are installed. The recall basicly rerouted(and added a relay) the blower motor because they tended to overheat ignition switches when run on high for extended periods of time. I have no idea if this is why my previous switch failed but it shouldnt be an issue now.

However, since I put the new swicth in(used old key tumbler) my buzzers been going whenever a door is open like a key is still in the ignition, a little annoying but doesnt seem to hurt anything.
 

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Discussion Starter #15
ImperialCrown said:
The Dk Bu/Yl wire is the return wire that should be under 2 volts when the PCM (pin #51) is grounding the relays.

Dk Gn/Or at PCM pin # 57 needs to be the 12 volt ign in.
Rd/Wt at PCM pin #3 needs to be 12 volt battery in.
Bk/Tn at PCM pin #11 and #12 needs to be a ground with 0.3 volts or less to the battery (-) post. It is good to measure all voltages to the battery posts because a connection may still be good from the point of test to body or frame, but have a high resistance from body to battery. You don't need misleading tests.
Is it safe for me to run a jumper across these direct from battery just to see if it gets the connection it needs? i wouldnt drive it that way, but if I ran a jumper from the + to #57 or #3 and suddently it energized immediately with the key on it would sure pinpoint the troubled circuit. The same thought applies to 11 - 12 with a direct ground jumper. It might be a really bad idea, but its just a thought. I dont want to damage anything.
 

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It can save you both time and frustration to run a jumper in parallel to the circuit under test to see if it responds favorably.
If there is a high resistance condition that goes away with a jumper crossing it, it will help you further pinpoint the circuit or wire color that needs attention.
You may see a small spark when connecting a jumper wire if all of a sudden the electricity sees an easier path to follow to get where it needs to go.
 

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Discussion Starter #17
I've still been digging without luck yet.. believe me its not from a lack of trying. Ive had limited time to work on it.. 30 min here, hour there.

I'm now looking around for better leads for my meter, something that can penetrate the insulation on the wires for faster testing would be ideal. I know this isnt the best thing for longevity of the harness, but a little liquid electrical tape goes a long ways.

I drove the truck yesterday and it stalled on me driving down the road at 30 mph at lower operating temps, it did restart but didnt want to keep running. I got a CEL and a code 14(OBD 1) which is map sensor. After I drove the truck a few more blocks it smoothed out and ran fine for the next hour without a hiccup. (I immediately tested this when I got home and its within specs at a range of engine speeds)

I totally forgot about this but a few weeks ago when the truck stalled the 1st time on the freeway it gave me a CEL with a bunch of codes ... 12, 14, 21, 42, 43, 47

12 bat disconnected (replaced 2 days before)
14 MAP out of range
21 O2 sensor too lean or rich
42 ASD relay open or shorted
43 Ignition Coil driver circuit open or shorted
47 Battery Charging voltage out of range

I had the truck scanned on a good scanner when running about a week prior and everything looked great at that time(and no codes). Keep in mind these codes were triggered trying to restart the truck immediately after stalling on the freeway and I forced it to keep running(bad limp mode?) to get the truck to the exit because my kids were in the truck. I turned the truck off for about 5 min at a gas station and restarted it and it ran good for the next hour home.

That was the day it became obvious I had a electrical failure going on and the ignition switch decided to give out about the same time. The probelms didnt rearise for a while because we had unseasonably warm weather.
 

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All of those codes will be tripped by an inadequate ground, so be patient and keep looking. I assume you have looked up into the cable insulation at the negative battery clamp, where the strands feed in, to see if there is corrosion or missing strands?
 

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Discussion Starter #19
The negative battery cable is brand new, I brushed down the contact points, and have cleaned every engine ground contact surface I have found. Every existing ground im aware of has great contact. I did have 1 cleanly broken ground strap that somehow happened recently, it was replaced and had 0 noticable effect on the situation.

I incidently just narrowed my search. On the passenger side of the motor i was trying to get the harness unstuck from the retainer and flexing a couple different splices off the main harness, and pulled the cap off the PCM plug in and went to turn on the key and the circuit charged right up and the vehicle started perfectly without a hiccup in 10 degree weather... so this tells me i have a bad wire somewhere in that area. I tried to flex the harness in the same areas to get to to re-fail and I couldnt. The connections appeared to be super clean to the PCM when i had the plug out yesterday, that doesnt mean the connection is good to the plug itself I guess.

Long story short my search is now refined to the PCM connector and a 4' space and a handful of wires vs 20 miles of wire. All of the wires in question are wires stated in previous post. The help from you guys has been priceless and right on. Now the chore of disecting the harness and finding it if I cant get it to refail to catch with the meter. it could be a live or ground wire within the harness.
 
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