1988 Dodge Dakota Voltage Regulator Problems

I've been having problems with my 1988 Dodge Dakota voltage system, where the battery voltage drops down to 12.6-12.8v after about a minute of running.
All of the normal things have been checked and replaced, but my journey trying to solve this problem lead to a strange relay/switch located above the lower part of the steering column, above the high/low switch for the headlights. It's actuated by the key ignition cylinder via a long rod.
I'll post an update in the comments once I figure out a replacement for it.

[@GGigabiteM]

So the problem did turn out to be the ignition switch. I replaced it this afternoon and the charging problems vanished.

[@6milpesoman]

Good on ya, wiring probs can be a pain in the arse

[@GGigabiteM]

@@6milpesoman Yeah, especially a 31 year old crispy wiring harness. Parts of the wire are so hard that moving them slightly causes the sheathing to flake off. I've been slowly replacing wires as they go bad, it's not a fun task.

[@6milpesoman]

@@GGigabiteM i feel the pain of doing all the wiring work that it needs, its not fun but a necessary evil, least a learning experience

[@hindflight]

In '88 it was the first year that the 5.2 and v6 used EFI, the 5.9 was still carburated and had an external voltage regulator. that's why the guys at O'Reilly's kept on referring to a Voltage regulator. The voltage is regulated by the SCEM or PCM on these cars. A common mod is to wire in a voltage regulator since it's cheaper than replacing the SCEM.. Glad you were able to trace down the problem although ignition switch wouldn't have been my first guess. :)

[@GGigabiteM]

A voltage regulator mod would not have fixed the problem. The copper contactors and bus bars inside the ignition switch had such high resistance that they were causing a voltage drop of sometimes up to 4-5v. This caused secondary cascading failures (since everything goes through those contactors) of the headlight switch and hi/lo switch quite literally melting and smoking. I was measuring 14.5v coming out of the alternator, but only 10-11v at the battery and anywhere else. This is why the auto parts stores thought I had a bad alternator. This whole fiasco started when my headlights would randomly shut off and start flickering. Traced it to melted headlight and hi/lo switches. I burned through six of EACH before I figured something else had to be wrong. These switches were also getting so hot that they were melting and smoking. The reason they were melting and smoking is because the voltage was too low, which caused the current to exceed the rating of the contactors and wires. Likely what would have happened if I just slapped in an external voltage regulator is the truck would have burned down from all of the wiring getting grossly overloaded and burning. As for the first Dakota that had TBI, the first model year 1987 Dakota had factory option TBI, but it wasn't very popular. It was expensive and didn't really offer any benefits over the standard 2bbl carburetor. Even less popular was the smaller I4 engine, I think I remember seeing that less than 4% of all 1st gen Dakotas sold ever had the I4. Strangely enough, there was a TBI for the I4 engine! It only had a single fuel injector in a tiny baby throttle body. I've only ever seen one of them.

[@troylewis684]

1990 D150 almost exactly what I'm going through. Thank you

[@TheOneAboveAll-001]

I am very glad you decided to record your detective work I too am having some of the similar issues currently I am having a idle problem with my 90 Dakota and I have replace the speed control valve and I was wondering if maybe the wiring is bad or the unit that sends the signal which would be the ECM is bad. Thanks for recording and logging in the videos because I would have quit a long time ago.

[@GGigabiteM]

Check for vacuum leaks and plugged vacuum lines. The 239ci V6 is ridiculously sensitive to vacuum leaks, and even a tiny pin prick of a vacuum leak will cause the engine to run very poorly. A plugged EGR can cause weird issues, and it can be a pain to clean because the intake manifold EGR passages can become so clogged that you have to remove it and manually clean it out. Also, check to see if you have a good working oxygen sensor. The PCM will go crazy and flood the engine with so much fuel it will stall and run badly. I worked on an 89 dakota the other day that was a no start and it had a melted wiring harness in the engine bay between the battery and firewall on the drivers side. There are fusible links there and if they are compromised, you'll have electrical gremlins. The same goes for the relays on the same side. Relays dont last forever, they'll get pitted and charred and will also cause issues.

[@leatherpunk]

This solution worked for me! Fantastic diagnostic work. For me, the issue was not persistent, sometimes it was fine, which made it harder to pinpoint. As I'm watching your video, I'm saying to myself, "Yep, did that. Yep tried that. Yep, about to buy one of those." etc....Except for the ignition switch, which I would've never considered. Mine is a 90' Dakota, I acquired it from a buddy who inherited it and let it sit in a garage for 5 years, it had a bad starter, bad fuel pump, mouse nest on the valve covers, so I surely thought mice chewed up wire insulation. But it looks like it was the switch after all. My only additional advice for others would be to check your 'alignment' on your key ignition before you tighten everything and close it all up. I didn't do this and now my key goes in and out kinda rough, like it's not in sync with the switch position, but only slightly. So now I have to go back in and loosen it(the ignition switch) and adjust it, which is why the switch has oblong screw holes. Thanks again!

[@GGigabiteM]

Rodents tend to leave the wiring harness alone, but they LOVE to eat the fuel lines going to the tank. I had asshole rats eat both fuel lines going to the fuel tank four times in a month. I got so sick of having to jack the bed up to fix the lines that I made an armored sheathing out of steel wire to cover the entire length of both hoses, haven't had an issue since. Also got a bunch of cats that got rid of the rats too. For the rodents on the valve covers, get those green rat poison blocks and put a couple in the valley on top of the engine. It'll kill all of the rodents that decide to take up residence in your engine bay.

[@leatherpunk]

@@GGigabiteM lol, "How to rat proof a vehicle fuel line"...you should do it.

[@GGigabiteM]

@@leatherpunk Definitely on the Dakota, because the fuel line is in a stupid location. It's exposed to the drivers side rear wheel well, so road debris can be kicked up and damage the line as well. I've had rocks and junk get flung up by the tires and puncture the lines as well.

[@leatherpunk]

@@GGigabiteM Yeah, I'm not in love with this truck. Oh by the way, I'm back to square one, the check engine light came on again, voltage dropped. It does it for a few minutes, then it bounces back. It's not persistent/constant. Although, when I first got the trucking running last month, the issue WAS persistent. The next 'part' i buy is going to be a For Sale sign.

[@GGigabiteM]

@@leatherpunk I like first gen Dakotas despite the weird issues they have. It's the only vehicle that I've ever been able to get in and out of without jumping way up or crouching way down to get into. I can just slide right in, and everything is in the right place. I'd offer to buy it if it was cheap enough, and not a rust bucket, but according to your website, you're across the country lol.

[@zaeronopranks7510]

Where could I order the part for my 94 Dodge Dakota V8 ?

[@ivannolasquez8364]

Hola el cable verde i el asul cual es la funsion cual activa la lus del tablero de bateria

[@larrywood1201]

I got a 88 that sometimes when you try to start it up it wont turn over. key on put it netu it starts right up. this fixed it for few times but have to put back in netu.charges fine

[@camg6603]

When you mean ignition switch do you mean the key switch or the black box from your steering column? I’m havin the snake problem on my 91 right now

[@GGigabiteM]

The black box is a mechanically driven ignition relay that connects the alternator and battery together. I've thankfully not had problems with the ignition key switch yet. If you're having charging problems, there are a number of places you'll have to check, starting with the alternator. If you get good voltage from the alternator, check the field windings. One will be grounded and the other will go off to the PCM. You'll want to pull these wires out of the wiring harness to see if they're damaged or not and repair them if they are. The ground wire on mine was damaged in a hidden location under the vacuum relays and I had to re-run the whole wire, and redid the other to the PCM since it was dry rotted. The next expensive problem is the PCM having a fault, because the voltage regulator board is integrated into the PCM. These are pretty expensive, but are generally not too hard to find, mine was about $250. After that, all that's really left is the firewall plug and the ignition relay in the cab.

[@surfreadjumpsleep]

Man you are persistent! Well now I'm not so sure about this project. I did start to wonder when I learned my inherited 1987 Dakota was the very first year production. Hearing your struggles well maybe I will sell it to the guy that wants to hotrod it. Or maybe someday if I get the money I could tear out the engine & put in an electric engine & some batteries in the back.

[@GGigabiteM]

I'd at minimum suggest pulling the engine/trans and putting a Magnum setup in it. Parts availability is way better, fewer headaches and more power and fuel economy. I wouldn't recommend hotrodding it, the truck is too light to have any sort of big power increase. Even the stock 125 HP V6 can spin the tires. Going to a Magnum would be the least amount of work and probably the cheapest if you can find a wrecked truck to steal parts from.

[@surfreadjumpsleep]

@@GGigabiteM yeah I have the 1987 v6 3.9 version. Is this the ultimate Dakota unicorn? He treated it like a baby back in the 90s in Georgia. He didn't drive it much for the next 20 years in Maine. I am hopeful that it mostly just works. Just now I'm replacing the valve cover gasket but I'm noticing orange gasket material coming out from the seams of whatever the next level down gasket is.

[@GGigabiteM]

@@surfreadjumpsleep you're either looking at the intake manifold gasket or the timing chain cover/water pump gasket. If either of those is leaking anything, they need to be redone. Coolant flows through both the intake manifold and timing chain cover, so if you have a leak, it's very easy to get coolant in the engine oil.

[@GGigabiteM]

@@surfreadjumpsleep as for being a unicorn, the first gen dakota was only made for 3-4 years, so parts are very hard to get.

[@surfreadjumpsleep]

​@@GGigabiteM ​ The car does blow white smoke at start... but then it's cold out. Still, there is an excessive amount of white smoke. The oil is not at all creamy though. I now think that my Dad might have put that orange gasket sealant on. I remember he and his friend took the engine out and rebuilt it one summer in the mid 90s. I'm not sure why he did that because the truck was so new then. Thank you for the tips. I may have more detailed questions once I start to dig into the truck. Are you going to swap out your engine for that other one you mentioned?

[@ryanlatham3155]

Im having same problem with my 87 dodge dakota truck did u ever figure out name of the part under the steering wheel would gladly appreciate it so i know what to buy

[@GGigabiteM]

Start switch.

[@randy1ization]

my 89 dakota is charging at 12.60 to 12.70 volts,, it increases when revved but never goes to 13.0 or higher.. headlights are bright, but I know its not charging enough . replaced alternator and battery.. cleraned crusties at plug connectors. will check other things tommorow.

[@GGigabiteM]

I'd replace the start switch next and check the wiring harness.

[@ryanlatham8385]

I'm having same problem did u ever find out the name of that part under the dash

[@GGigabiteM]

It's an ignition switch. Orilleys has them for about $25

[@6milpesoman]

If im not mistaken its labeled as a "Ignition starter switch" on Rockauto, Cross reference the part numbers they give to oriellys or so

[@GGigabiteM]

Yeah, I found it late in the evening. I'm going to go buy one and see how it turns out.

[@andrewedwards7356]

@@GGigabiteM hey buddy I have the same problem right now and I've been spending so much money on it . If I could your help it would be greatly appreciated. But i watched your recent video and same thing that is happening to me . And you have went alote further ahead then me with getting it fixed .

[@GGigabiteM]

@@andrewedwards7356 It's a really bad idea to post your number on a public forum, I'd remove it. You can talk here about what problems you're having and what you've tried so far. It'd also help to know which Dakota and what year model you have.

[@andrewedwards7356]

@@GGigabiteM 1991 single cab le 318 v8 dodge Dakota just need to know if you fixed your truck and it's not training the battery.

[@GGigabiteM]

@@andrewedwards7356 Mine never had a battery drain issue, it just wasn't charging the battery at all. Yes, it is fixed now that the bad ignition switch was replaced. You have a second gen Dakota, I'm less familiar with them, but can still try to help. If you're having an issue with parasitic battery drain, you'll need to figure out what's causing it, it'll be a different problem than what I had.

[@surfreadjumpsleep]

Alright so now I see from your other videos that you understand electronics & computers too, so how about just replacing all the electronics / electrics in the Dakota with some sort of raspberry pi & relay board. You could even have a tablet in the middle like a Tesla and remote control everything from that.

[@GGigabiteM]

There's nothing stopping you from doing that, but no sense in reinventing the wheel when aftermarket ECM/PCMs exist. There are kits you can slap on almost any engine and tune to your specific vehicle, but be prepared to pay to play, they're not cheap. PCMs for the Dakota are surprisingly still available from auto parts stores, probably because they were used on other Chrysler vehicles as well. While you could theoretically use something like a raspberry pi as an ECM, it's in no way designed for such a use, and I would never trust it to be reliable enough to use as a daily driver. Getting the stoichiometry correct on the engine is a complex process, and I'd sooner slap a carburetor on before trying to design my own fuel injection system.

[@surfreadjumpsleep]

@@GGigabiteM I hadn't thought about engine timing sorts of uses of the power. For my own use case I've got simple blinker problems & also high /low beam control & also no windscreen spray or wipers. I figure if it isn't the fuses then rather than continue to use the old wiring then maybe just use some hobby switches on a piece of wood for a control panel. we'll see. For you I thought this voltage control could be solved with something more simple than existing wiring, but I suppose voltage regulation is pretty much the bedrock of the whole system.

[@GGigabiteM]

@@surfreadjumpsleep The high/low headlight function is controlled by a mechanical relay attached to the lower left part of the steering column. There's a long metal rod sandwiched between the blinker stalk and the relay a foot or so down the column. That relay goes through the push/pull headlight switch on the left side of the dash, which in turn goes through the start switch on the top of the steering column. It's why I recommended to replace all three because they can all cause all sorts of issues. When you change the high/low relay and the start switch, be sure to mark the position of the screws because both are controlled by long metal rods that need the correct preload set. If you get it wrong, the rods will either fall out or when you turn the key or actuate the headlight intensity, it won't work right. As for the wipers, make sure that the mechanical linkage under the vent cowling hasn't fallen apart. There are plastic/rubber bushings that link the metal pieces together and they dryrot to dust over time and cause the linkage to fall apart. I've had to redo my wiper linkage a few times already. The same happens for the transmission shifter linkage under the truck, it uses the same plastic bushings that rot and crumble to dust.

[@TheOneAboveAll-001]

Lol

[@robertshields4603]

My 93 dodge dakota is overcharging 3.9 magnum

[@bornontheusa408]

Hi, are you able to get some data for me? im looking for the name of one integrate circuit of the ecu, because mine burn out and i want to repair it pls.