Non-charging help 89 Dakota

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ragtopfury

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My Shelby Dakota. Pulled the throttle bodied 318, threw together a warm little carburrated 360 with a stand alone mopar electronic ignition. All emissions relayed wiring is not terminated, just laid back out of the way. I have all original ground straps bolted to the back of the head. The original computer still has its power feed and grounds. All dash guages and lights work, except for the tach.

I have full battery voltage at the hot post on the alternator. I have less than 2 ohms from the ground post to the body. I know that both fields feed into the computer and would think they'd feed back out for charging to take place.

Do I need to wire one of the files into the ignition like a 74 Dart?
Do I need to bypass the computer and wire in an external regulator?

I've got a factory service manual for the truck, but lose sight of the fields when the enter the computer.

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If the computer will not operate the alternator you can install a 70/ later Mopar external alternator. First, I would.......

Disconnect both field wires and isolate them "safely." Check both wires with the key "in run" and I believe one should have 12V

You can check the alternator alone (they work just like a 70's Mopar)
Check resistance between terminals. Should be very low. check resistance from both terminals to case. Should be infinity. The field is simply an electromagent

Ground either field with a jumper wire. Connect the other to a battery source and run engine. Voltage should rise, but be careful not to let it go above 16 or so.
 
to me (no computer controlled car expert) it sounds like the computer is expecting a signal from something to tell the computer that the engine is running and start regulating the alternator output. My guess, there is a crank position sensor that is not hooked up, so the computer does not know the engine is running.

as for fix... what 67 dart 273 said
 
Thanks Del - sounds like a great place to start, and fairly basic.

Dana - there was no crank position sensor on the original motor.
 
to me (no computer controlled car expert) it sounds like the computer is expecting a signal from something to tell the computer that the engine is running and start regulating the alternator output. My guess, there is a crank position sensor that is not hooked up, so the computer does not know the engine is running.

as for fix... what 67 dart 273 said
That is a point. If the engine was getting RPM triggers the tach should work "I think."
 
I used to own a 07 Ford Focus and the PCM controlled the alternator. I had to clear the codes after replacing a bad alternator.
 
My 89 diplomat had that same alternator with an external regulator. I'm thinking that if you're not running the whole factory efi setup that's gonna be your only fix.
 
I tested things as Del laid out in post number 2. Looks like I'm going to wire in an external regulator at lunch tomorrow. I've got a couple of used regulators and at least one factory pigtail on a shelf somewhere.
 
I too have a Shelby Dakota #660. My computer took a dump but I was able to clone it to get the truck working again. So the 1989 computer has two boards in it. The top board with the small connector is the board that controls the alternator. The second board withthe large connector is the engine management. It is possible the Alt board is bad. The capacitors are like likely bad just due to there age.
 
Mine is #321. Bought it new. Wife says sell it. We honeymooned in it. I refuse to sell it. It's too much fun to drive. LOL
The charging circuit was working the day I took the truck apart. I know crap can go bad at any given moment, so who knows. One more thing to look thru, I guess.
Any Idea on the tach function. I believe the diagram shows it coming out of the main board on pin 50. But trying to figure out if I can bypass that and wire it directly?
 
Hot snot, we're back in business! Wired in an external VR, and all is well. Except the tach. Not worrying with that at this time. Tags and registration next week. I did not go with the $500 stripe kit.

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I did all that, turned out a brush shat in the alternator. I fixed the brush but left the regulator on the firewall as a redundancy. Glad you got it going.
 
Nice to see you got your truck up and running.
The dakota's SMEC computer controls the tach. I messed a little with a stand alone tach driver but did not have any success. Did not spend much time on it. Not all of the Smec for the dakota's have the tach driver in them. So when cloning you need to find a smec that has one.
 
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