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Electrical Headaches

Posted By: Jay85128

Electrical Headaches - August 25th 2019 5:58 pm

Hey All, Apparently I am not the greatest mechanic, so I wanted to ask for opinions here. My 74 B200 tradesman is having electrical issues. I started it one morning to warm the engine up get ready to move things around in my yard, when I went to start it again I heard one click in start (crank position), tried again and nothing, tried a third time and heard sparking noises from what sounded like lower right of steering column. Has not made any noise since, but I am for some reason getting power at the back of the ignition switch at all positions at once (ign1, ign2, and start). I am sure I am only supposed to get power to those positions when the ignition switch is turned to that position, and the switch checks out good when the it is removed and bench tested. I am sure something is shorted out, but so far I have not found where it is. Everything I have checked looks good. but of course that does not mean that it is. None of the fuses were bad, but replaced them all anyway, fuse block appeared to be undamaged. I have not seen any bad or melted wiring anyplace as of yet. The battery was removed, tested, and charged for over 12 hours to make sure I had ample power to test the rest of the electrical system. I am about ready to pull the dash out so I can get a better view of what is behind it and maybe find the issue. Does anyone have any thoughts on the problem? Thanks for reading and for any help you may have to offer.
Posted By: CatFish

Re: Electrical Headaches - August 25th 2019 7:49 pm

Jay I know next to nothing about Dodges.
I do know they have a connector at the firewall that plugs most of the under hood and under dash wiring together. (seems like it's about a 2" or 3" square IIRC) These can corrode and/or short out over time and, because they're sometimes covered in sealant, still look fairly normal from the outside.
It'd be one place to start that's comparatively easy to access. If you disconnect there it may tell you if your problem is inside or outside .......

Maybe the Dodge Boys will chime in ......
Posted By: Reed

Re: Electrical Headaches - August 25th 2019 9:08 pm

The ignition switch power feed will have power at all times in all positions. It is the output that changes based on the switch position. I would do the following:

(0.5) get a factory service service manual with wiring diagrams and a troubleshooting section
(1) check the cleanliness and tightness of the battery cables at the battery and where they attach to the block and starter motor.
(2) check the connections at the starter relay on the firewall.
(3) try starting the van with the transmission in neutral. If it starts, you need to either adust the shift linkage or replace the neutral start switch
(4) check if you have dash lights and brake lights. If so move on, if not, check the fusible link in the + battery cable.

There isn't much to the Dodge starting system on these old vans. Most likely you have loose or dirty battery cable connections or a failing starter relay.
Posted By: Meanmachine

Re: Electrical Headaches - August 25th 2019 9:46 pm

Possibly the fusible link
Posted By: wrcsixeight

Re: Electrical Headaches - August 26th 2019 6:46 am

On my 89 most all the wiring to from the ignition switch runs through the bulkhead connector, A known weak point as rain water likes to drip under hood and down firewall around the bulkhead connector.

Didn't mopars of this era also run amperage for the Ammeter through the firewall or had they given up on that by then

Sparking coming from ignition switch did likely blow a fusible link, which do not always stretch out and look burnt like they are supposedly supposed to do.
Posted By: Reed

Re: Electrical Headaches - August 26th 2019 5:43 pm

Yes, the ammeter is probably a full-flow ammeter, but I wouldn't look there first.
See here:

https://www.allpar.com/history/mopar/electrical.html

https://www.allpar.com/fix/alternator.html
Posted By: Jay85128

Re: Electrical Headaches - August 31st 2019 3:18 pm

Well thanks everyone for the responses, the input is very much appreciated. Now I have some new ideas to check out.
Posted By: Jay85128

Re: Electrical Headaches - August 31st 2019 10:09 pm

The problem is fixed, was a bad connection in the main battery ground cable. I was sure overlooking the obvious and over thinking the problem. Thanks for the help.
Posted By: wrcsixeight

Re: Electrical Headaches - August 31st 2019 11:04 pm

weird + electrical + Dodge = Ground, 99.9% of the time

Glad you found it.

I know a lot of pwople will see corrosion on battery and battery terminals, cleanup the exterior to perhaps even shiny copper them up and say:

'I can't possibly see how this could be an issue!"

But it is.

Please note a lot of the Autoparts store bought cables, the ring terminals which are suppose to bolt to the block are just mild steel compressed over SAE gauge wiring, with a hole punched through it.

Steel is a poor conductor, and that open stranding inside where they drilled/punched the hole for the bolt, will allow corrosion to wick up the stranding quickly, and the whole dissimilar metal thing will just accellerate it.

In general most autoparts store battery cables are total junk and temporary at best. the only variable factor is how temporary, and recently replaced stuff tends to be immediately ruled out when problems develop again.

With these steel ring termionals bolted to teh engine block and or the frame/ body/firewall, make sure all mating surfaces are snimy, even the bolt threads, and use some grease to cover them and prevent oxygen/moisture intrusion, and regularly check their tightness.

SAE gauge wiring is 6 to 12% thinner than AWG wire, and as such has lesser current carrying capabilities.

I have some of those cheapo autoparts store cables in use, but cut off the steel ends and hydraulically crimped on new terminations/ ring terminals. The copper closes the steel was almost black in just a year or two use, had to cut back 8 inches or more before it started to look like shiny copper.


Always suspect battery cables when weird electrical things start occurring, and simply cleaning the brocolli or cauliflower from them does not mean they are good to go.
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