What should I do here?

[episodic]

I have an old beater truck I use to get to work and back - a 91 dodge ram that has been around the bend and back. The power steering fluid leaks, there is a leak in the gas tank if you fill over 1/2 full. It stalls ocassionally. . . etc.

I never drive it over 10 miles at a time sort of thing.

I paid $1100 for it a while back ago.

I go to start it other week - and no crank. The battery was 6 years old - so of course that is my 1st thought. I replace the battery. A week later the same thing.

So I figure it is the alternator.
Take it to a local mechanic shop that was recommended to me.

So they call me back saying the alternator is only putting out 11 volts and I authorize it's replacement and install at around 320$ all together.

Fast forward to today - I just got a call and they said that after they placed the new alternator on - something was still wrong. They said they went over the wiring, etc. . . and found out that the ECM was bad. So they said there wasn't anyone in town who had a 'tester' for my particular ECM - so they got one to test it and put it in and they said after that everything worked fine and my system is up again.

The problem is that I didn't authorize this - and they know it. . . The bill is up to around $650.

If they had told me it would have been that much to begin with, I would have just sold the thing for parts and found me another beater. . .

Is there any BS to all of this? Is it really that expensive (300 more dollars) for this part, etc. ..

Anything I should ask or look for? What if I decide that I don't want that done - what are my rights?

I'm not that knowledgeable about this - so I want some 'good thoughts' and things that I can come back with. . . . .

Here is what I am wondering, could it have been the ECM and not the alternator? Should mechanics not know how to figure that out? What if the alternator was good and the ECM bad - and I am paying double?

 

[PhoKingGuy]

You didnt authorize it, you don't pay for it. Simple as that

 

[episodic]

You didnt authorize it, you don't pay for it. Simple as that

I get that, but I'm sure they'll pull the new computer off - put the old on and I still owe for an alternator that I authorized that I have a sneaky suspicion was the computer to begin with that was simply misdiagnosed.

I guess I'm just wondering does all of this sound right?

 

[MovingTarget]

I get that, but I'm sure they'll pull the new computer off - put the old on and I still owe for an alternator that I authorized that I have a sneaky suspicion was the computer to begin with that was simply misdiagnosed.

I guess I'm just wondering does all of this sound right?

Sounds about right on the first count. I don't think that the alternator output was misdiagnosed though, unless it was done intentionally (shady mechanic). Those are dead simple to test and an ecm shouldn't interfere with its output, IIRC.

 

[exdeath]

Computer has nothing to do with the alternator. The alternator is self regulated based on electrical system load.

I've heard of some new systems where the alternator is controlled by ECU feedback but not on a 91 Dodge.

Computer problems are going to cause all sorts of strange issues, mostly intermittent issues with emissions and driveability, random stalling, etc. But in your case your primary issue is a dead battery backed up by the verified low charging system output, eg: alternator.

Once your charging system is putting out the proper level (eg: 13+ volts), if you continue to have a problem with key off draining and dead batteries, it's conceivable you have an electrical problem somewhere as well. For now, go with what you know to be bad and take care of one thing at a time instead of just wasting money on random parts for no reason.

 

[Malak]

Somehow my post disappeared. Doesn't anyone else find it odd that they claimed the ECU was bad even though they admitted to not having a tester for it?

 

[NutBucket]

Well, the installed a known-good ECU and everything worked. There's some logic to it.

 

[Pacfanweb]

Well, the installed a known-good ECU and everything worked. There's some logic to it.

The voltage regulator in those old Rams is INSIDE the PCM, if memory serves.


So you likely had a bad voltage regulator to begin with, and the alternator was fine.

I'd be looking for them to either eat the new alternator, or reinstall my old one, since you had the exact same problem after the put the new one on.

 

[Malak]

Well, the installed a known-good ECU and everything worked. There's some logic to it.

But he has no knowledge of this, only what they say. Their story doesn't add up, so it's entirely possible that everything was working fine without the new ECU and they are risking it to get the extra cash. Maybe they had one of these ECU's on hand in the back and are trying to unload it finally. I've worked a parts shop that had plenty of old stock that we were thrilled to get rid of any chance we got. Legit sales, of course, but you never know with shady mechanic shops.

 

[exdeath]

The voltage regulator in those old Rams is INSIDE the PCM, if memory serves.

Well I'll be damned. I just did some quick Google searching and found references to regulators built into the engine computer as well as methods to convert to external regulators. 😵

The Electronic Voltage Regulator (EVR) is not a separate component. The voltage regulator is actually a voltage regulating circuit located within the Powertrain Control Module (PCM). The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.

So OP's case is legit. You'll need a new PCM, but you should not be paying for the misdiagnosed alternator. It appears they made the same mistake I did initially in assuming the regulator replaced with the alternator (though it should have occurred to them something didn't quite look right with the alternator as soon as they went to remove it). The setup you have isn't very common; the majority of cars made from the 90s to today have the regulator built into the alternator and it's all replaced when changing the alternator out to address lack of charging.

Due to the cost of a replacement PCM and this exact issue, there is lots of info on the web regarding using a replaceable lower cost external regulator. Might be something to look into.

http://www.dieseltruckresource.com/faq/faq.php?display=faq&nr=161&catnr=20&prog=1&lang=en
http://www.thedieselgarage.com/forums/showthread.php?t=58251

Just found these for the diesels, but should be similar. The external regulator is connected to the electrical system via ground and +12v to sense system demand and uses that to control the field current via the two wires going to the alternator. Should save you some $. Looks about like $10 for the regulator from any previous generation externally regulated Chrysler and $3 for a spool of 12 gauge wire, and some screws and washers from the hardware store to secure it to the fender/firewall.

http://cgi.ebay.com/ebaymotors/Chry...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

If you want to go this route, ask them to remove the new parts and just pay for their time and diagnostic services, or even see if they can install the external regulator for you. It is just a beater.