u/Rustishacklfrd — reddlx

ECU Help

Need an ecu. 92 3.9 auto 2wd. Federal emissions from what i can tell.

Sticker on my ecu is dirty / worn but can make out what looks to be a 21 as the last 2 digits of part number. Dealer pulls part # R3008921 as part number which makes sense with the last 2 i can see. However that part number seems to pull up listings for an ecu for the 2.5l. Based on research the 3.9 part number should be 56028741. Has anyone run into this? Also listings show compatible years from 90-95 but other research shows 92-93 due to changes made within the pcm before / after those dates. Just want to make sure I order the correct one. Thanks

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u/Rustishacklfrd — 19 hours ago

▲ 1 r/DodgeDakota

Is this normal?

Obviously the corrosion is not but I have a power wire from the a/c clutch / rad fan fuse twisted together to 1 wire each on the starter and ac clutch relay. Best i can tell it is taking constant battery voltage from the fuse and supplying power to the relays. Dealing with a no spark issue and found this. Doesnt seem related as the truck ran prior with this being the way it is.

u/Rustishacklfrd — 6 days ago

▲ 0 r/DodgeDakota

Pickup coil

Crank no start, replaced pickup coil, dist cap and rotor. Fired up. Ran for 100 miles and shut off. Back to crank no start. Checked the 3 wire splice. Good connection, no corrosion. I was getting odd voltage readings at battery. 14.5v then spike to 18v then drops to 3 then back to 14.5. But power at alternator output to battery was a constant 14.5v, never had the spike or drop. Was thinking bad connection on that cable. Since truck died again, found no spark again. Coil ohm’d good. Pickup coil only showing 2ish ohms. So looks like pickup coil is bad again. New aftermarket coil with less than 100 miles. You think the coil just went bad or would the bad alternator to batter cable have caused a failure?

I just find it weird that a bad cable would show a spike, if anything i could see a drop. If the voltage at the alternator output never increased how did i get an extra 4 volts then a drop at the battery that never showed at the alternator output?

Battery is brand new and tests good.

Anyone see a failure of their replacement pickup coil?
Does those voltage reading make sense to anyone?

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u/Rustishacklfrd — 8 days ago

▲ 1 r/DodgeDakota

Alternator Help

Replaced dead battery. Charging at 14+ volts then spikes and drops then doesnt read at all. Only when testing at battery. When testing at alternator it is a consistant 14.5 volts. To my understanding the voltage is regulated by the pcm. Should i bypass the pcm and put an inline regulator direct to the battery?

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u/Rustishacklfrd — 9 days ago

▲ 6 r/DodgeDakota

New to me. Lost spark

Just picked up a 92 2wd 112” wb that came from factory as an incomplete vehicle. Bought it for camping / transporting my motorcycles around. 1 owner (dealer parts truck) and they installed a flat bed. Ton of service history dating back to new. Recent transmission rebuild, tires and fuel pump among other smaller items.

Would start and then stall. Finally started and ran / idled. Drove it across the street and then shut off. After this would do nothing but crank and no start. Was able to confirm there is now no spark going from the ignition coil to the distributor.

My understanding is the pickup coil in distributor sends signal to ignition coil then the ignition coil send spark to the distributor which then will send to each cylinder. Unfortunately my multimeter is at a friends house so I cannot test the resistance on the ignition coil. From some research it seems the pickup coil is a very common failure. Plan on getting a pickup coil, distributor cap and rotor, do you guys recommend throwing a coil on it for good measure? They seem cheap enough.

Also confirmed wiring coming from fuse box is not corroded or damaged. Swapped auto shutdown relay with known good ac relay. No change.

Thanks in advance for any help. Only have a couple crappy photos of the truck at the moment. But it is pretty clean (minus the paint).

Any thoughts on value once up and running would be cool as well. Only paid $500. No engine oil leaks, everything else works as it should. Surface rust only.

u/Rustishacklfrd — 20 days ago