1986 Dodge Ram. Won't start

[boilermaker52]

Hello,
I'm new to this sort of thing and I really need help from an old pro on this one. My Father-in-law has an old Dodge Ram 4WD with a 318, auto that won't start. It had been getting a little tougher to start as time went on but I figured the battery was to blame. The other day it totally refused to start even with a new battery. Thus far I've installed the battery, new coil (x2), ignition module along with a new cap and rotor and a new coil wire. All I get is a weak spark from the coil or from any spark plug (which are all new also). I've tried going right from the battery to the coil positive terminal with no better results. The carb is getting gas just fine by the way and it won't even fire on ether. It's always run well even though it's showing its age and I use it to keep 2 very large driveways clear. What could I possible be missing here? I don't have a Chiltons or Motors manual so I have no idea where any other component might be that I could check. I don't know what kind of controls might be on this thing such as an ECM or whatever since I don't have any manual. Help here is needed as well.
I'm appealing to anyone with expertise on this truck to guide me as the F.I.L is not well and needs to keep his driveway clear at all times.
Thanks to all who mull over this long post in order to render some sort of help.
Doug

[92d150lwb]

http://www.dodgetalk.com/forums/showthread.php?t=185862 that post which is in the truck engine technical forums should help you out a little.

[Chump]

Hello,
I'm new to this sort of thing and I really need help from an old pro on this one. My Father-in-law has an old Dodge Ram 4WD with a 318, auto that won't start. It had been getting a little tougher to start as time went on but I figured the battery was to blame. The other day it totally refused to start even with a new battery. Thus far I've installed the battery, new coil (x2), ignition module along with a new cap and rotor and a new coil wire. All I get is a weak spark from the coil or from any spark plug (which are all new also). I've tried going right from the battery to the coil positive terminal with no better results. The carb is getting gas just fine by the way and it won't even fire on ether. It's always run well even though it's showing its age and I use it to keep 2 very large driveways clear. What could I possible be missing here? I don't have a Chiltons or Motors manual so I have no idea where any other component might be that I could check. I don't know what kind of controls might be on this thing such as an ECM or whatever since I don't have any manual. Help here is needed as well.
I'm appealing to anyone with expertise on this truck to guide me as the F.I.L is not well and needs to keep his driveway clear at all times.
Thanks to all who mull over this long post in order to render some sort of help.
Doug


Doug, I'll help you out. Some questions so I know how to approach the problem solving.:):)

You say you replaced the ignition module, is that the one that looks like this?
http://img.villagephotos.com/p/2003-12/537508/ECUwithgroundhilite.jpg

Do you have a VOM or DVM meter to measure voltage or resistance?

Are there 2 wires or 4 wires going into the distributor?

Does it try to backfire thru the carb?

You do have the Dark Blue wire hooked up to the + side of the coil?

Try not to use any more gas until we get a spark back, you will dilute your engine oil and short out your new plugs.

How many miles on the engine?

I'm gonna post this wiring diagram and I want you to check/clean up the connections that are hilited.

[boilermaker52]

Hi...
Very happy to have someone out there who can help.

Anyway, nope. The module doesn't look like this so maybe I got the wrong thing in mind here. Maybe what I was talking about was the Pick-up(?) inside the distributor. (shows you how long I've been out of it). It has 2 wires going to it from the outside of the dist.
The dark blue wire is on the + side of the coil along with another wire.
It wasn't firing at all so there's no back firing.
I have a VOM meter.

Now, the strangest thing just happened just before I came in here to check my email. As I was trying to start it again with a set of AC Delco plugs (I took out the Bosch) I had my VOM on the coil + to check volts when my wife inadvertently pulled the head light switch thinking I could see better while she was turning the key. All at once the beast came alive!!!! I couldn't believe my ears!! I shut if off and it would not restart until I pulled on the headlight switch and the lights turned on! I tried this several times with the same result. Now what??!! I can't figure it out but I'm willing to try anything at this point.
Awaiting your response...

Doug Vensel

[Speed Dragon]

Wow, that is weird lol. Have you checked all the ground wires?

[boilermaker52]

Yes. That's one of the first things I checked was the grounds. I even set up a separate ground directly to the coil - terminal. Nothing. I just came in from a friend's house and went right out to try it cold. Same thing. It'll cranks till the battery gives up but if you hit the headlights it start up immediately. I don't know what's going on but I remember my father had a '54 Plymouth that did the same thing. He was never able to fix it either.
Any suggestions from the pros????? I suspect some sort of electrical path I haven't explored as of yet but I have no idea how the lights would figure into it.

Doug. :huh:

[DiverDwnPowrRam]

try this just to humor me. under and around your steering column are some wires with flat plastic connectors. see if any of these are melted. also check your firewall block for any suspicious melted areas.

[Chump]

Do you have a tilt steering column? The ignition switch and it's connectors like to melt on tilt columns. the ignition switch is located on the steering column near the bottom of the column and has 2 connectors plugged into it.

The extra wire on the coil, does it go to a condenser/tin can?

The picture of the module above is one type of ignition system...do you have this mounted on the inner drivers fender or do you have a black plastic box near the battery?

Unplug the 2pin connector at the distributor and measure across the 2 leads that come out of it. These are from the pickup asm inside. You should get 150-900 ohms.

[DiverDwnPowrRam]

i have seen this phenomenon happen on non tilting wheels as well.

[Speed Dragon]

Maybe replace the headlight switch? If I remember correctly, when the power comes through the firewall, it goes to the headlight switch first, then to the amp gauge and the alternator. Could be wrong though, also this is on an older truck (72-80). Not sure if the '81- are the same. Maybe the switch is grounding out the power somehow?

[boilermaker52]

Thanks guys. It's a nice evening and as soon as the wife units fixes me some grub I'm going outside, get out the night work light, and have a look at all the above. I intend to follow this through for my father-in-law. He doesn't need any more problems in his life and can ill afford to be stuck where emergency services couldn't reach him.
I'll keep you all posted.

Well, back to work!! Wish me luck!

Doug

[Chump]

i have seen this phenomenon happen on non tilting wheels as well.

Yes it happens on both styles of columns...it's due to excessive current draw and high resistence. Here's a pic of the wiring to a tilt switch that wasnt feeling too good!

[DiverDwnPowrRam]

Great pic Chump, that is exactly what happens. Seems like there should be a relay in there somewhere because of the "excessive" draw on current. just an opinion though...

[boilermaker52]

Hi guys.....
Been checking everything out that you have suggested until it got too dark to work last night. I don't have a garage or shop so I'm limited by the amount of daylight I have.
So far, nothing. It's light enough out right now that I'm going to go search around and look for the wires indicated in the picture.
Again, wish me luck. So far nothing has panned out. It's just too weird for me.

Doug

[hoodlum38260]

I agree with Speed try replacing your headlight switch.

[boilermaker52]

OK.
I'll give that a shot. I'll let you guys know what I find.
I'm headed to the parts store right now.

Doug

[boilermaker52]

Hey.....
I went out and started poking around below the steering column and without even knowing it, I fixed it. Upon closer inspection there happened to be a couple of bad connectors right where one of you guys told me to look. Evidently once the headlights were turned on, a new ground must have been "created" and the truck would start. Now, all is well and I can fix it permanately tomorrow afternoon.
Thanks a Load you guys. You're the BEST! My Father-in-Law wishes to extend his thanks as well. We took the truck up to his house and he was so happy he made a trip out to see it for himself. You guys saved the day

THANKS!!
Doug Vensel
Malone, NY :)

[DiverDwnPowrRam]

yeah that is exactly what happens around the steering column

[Speed Dragon]

Cruddy Dodge connectors strike again! lol glad you got it fixed.

[Chump]

Hey.....
I went out and started poking around below the steering column and without even knowing it, I fixed it. Upon closer inspection there happened to be a couple of bad connectors right where one of you guys told me to look. Evidently once the headlights were turned on, a new ground must have been "created" and the truck would start. Now, all is well and I can fix it permanately tomorrow afternoon.
Thanks a Load you guys. You're the BEST! My Father-in-Law wishes to extend his thanks as well. We took the truck up to his house and he was so happy he made a trip out to see it for himself. You guys saved the day

THANKS!!
Doug Vensel
Malone, NY :)

Good work! If you need help with parts like the electrical connectors or terminals, let me know.

Is that a tilt steering column?

[boilermaker52]

Thanks!
I will definately be back if the truck gives me a hard time again.
You guys are great!

Doug Vensel