I've got a problem that just keeps expanding and I hope to get as many ideas as possible before I jump on my 1985 D-100 this weekend. I converted the lean burn setup to a mechanical/ vaccum electronic ignition a couple of months ago and the truck cranked and ran OK but the motor seems to surge somewhat when driving easy. Last week when driving on the interstate the motor quits like there is no electrical power but after coasting for 10 seconds the thing refires and continues along with the same annoying surge, it feels little something is pulling electricity from the system. This week the power outages have became more frequent until yesterday I discover a dead battery and replace it with a new one. Today I go for the same drive with a less noticeable surge but again the same power outage for about 10 seconds then back to running along with the slight surge. When I first installed the ECU I used a red wire key switched power source that was dangling from the wiring harness near the ECU also near the bulkhead junction and I'm thinking that I may be wrong for using this as a power source. I think the surge may be the voltage regulator functioning in the circuit that I tapped into and that the 10 second power failure may be a fault in the circuit from my errant tap, but then again I thinking ignition switch, altenator, voltage regulator, etc. Any thoughts will be appreciated.

Hoo-boy. This could take awhile.

What ignition system did you swap to? Factory mopar? HEI? Did you buy a conversion kit or cobble on together (if cobbled, where from?)

What sort of lean burn system did your truck have? SCC? Lean burn only? Both?

There should have been some blue wires which powered the computer. There are the proper source to power your new ignition system

I'm not sure that it explains the surge, but the power cutting out and dead battery are definete ear-marks of a bad ignition switch. In fact, I'm not sure what else (aside from a wiring faut not related to the EI conversion) would explain the dying battery.

The wires from the computer got clipped but I can find them again if need be.

Tomorrow I will try to take some pictures of the way I have the ignition wired. I'm thinking that several things went wrong at the same time. I plan to disconnect the power from the ignition and wire it straight(toggle switch) to the battery and see what happens, if it clears up I will go for the ignition switch on the column. I changed the fuel pump and filter today to get that out of the way, the pump looked to be the original unit. I ran the motor just a little after installing the pump and did a quick check on the altenator and the battery is getting no juice. I pulled the voltage regulator and will check it out later, there may a ground problem with it too.

My votage regulator was draining my battery.

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82 D150 Slant6 Shorty
http://www.cardomain.com/ride/658846

I finally got to a point that I had to stop, the new ignition switch that I bought broke at one of the connections as I was installing it so I will wait until tomorrow to see if they will replace the switch. I have found many splits along the wire insulation on the main ignition red wire, for some reason the insulation on this wire is brittle but it doesn't look to be overheated, the wires that are next to it are still pliable, beats me. I have used about one-half of a roll of electrical tape rewrapping areas that looked suspect and hope that cures the fault if that is the problem. I bought the new switch because the old one was not consistent in making a true connection when I metered it so I'm hoping that a new one is a solution. There are still many too many probable causes to relax yet but hopefully tomorrow will find me back on the road, thanks again for the information.

I drove my "Redneckmobile" pickup to work today and it ran ok but still has a little surge which I think is a lean carb. I'll give it a couple of weeks and if it keeps running I may put a Super Six setup on it. At least now I can breath again when going down the road, nothing like going down the interstate at 70 with Peterbuilts all around and the D#$$#@# thing quits running, too much excitement for me!!

FYI - I have been into the wiring of two '85's, both had a red ignition switched power wire that was akin to the blue wire on '86 and '87 models.

Thanks for the info, the ignition wire from the ignition switch starts out blue but switches to red at the "horseshoe" coupler near the steering column on my 85, the wire I used to power the ignition is the emission accesory wire and is part of the switched ignition circuit from what my shop manual shows.

Whoops! My color identification came from my 86 van. I have seen the red wires on trucks though. I'd trust Super6 over me.

I'm back again with more problems, first I replaced the ignition switch and everything was fine until last week when the motor quit at a stop light. I replaced the ECU with an extra one that I had, the truck cranked and ran good all the way home. The next day the truck would not crank again so I got the multimeter out and began testing. With the ignition switch on I tested the voltage to the ignition ballast and got none but after that the motor would crank but would not run when I released the switch which tells me the run circuit is at fault for now. I can turn the ignition switch to start and it will crank everytime but when I release the motor stops also the switch can be turned to accessory and everything seems to run on that circuit. Do you think I have a bad ignition switch or should I continue my search, I thinking that I have have a bad ground since the truck is a 1985 model and the switch is only a couple of months old.

Sounds like a bad ballast resistor

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

I sorry to say that with the switch turned to run I'm not getting fire to the resistor nor to any other device. I plan to meter the horseshoe coupling connection for the ignition switch today to see if I am getting juice to that junction.