And the price was?????

Still got the MM?

 

Main reason I have two trucks(not discos). My alt went out a while back, got one from oriley auto. It has worked fine, no issues. Once my rover is right I'll work on my 4runner, bitch is a tank.

 

So my EE buddy Lew put a voltmeter on with long leads so I can read the VM while driving, and we first connected it to the battery terminals, and then to the excitation wire off the back ofthe alternator under the removable plastic cover on my Bosch. The battery is being charged at 14.4 volts when all is well, then the battery voltage drops to 11.4 or so immediately the system fails as indicated by no tach, no temp, and the battery light beign on (my failure is intermittant, failed about 40% of the time on any drive). The excitation voltage is 13.4 volts, unless the battery light is on, then it is 2.9 to 3 volts.

Does this mean that the problem is in the truck wiring rather than the alternator?

 

One question I have is regarding the tach signal. Would replacement of the voltage reg module also include the source of the tach signal?

 

If anyone removes an original MM alternator, please let me know. Instead of returning it to get a small core deposit back, please send it to me and I will be more than happy to do an exploratory analysis and document the results.

As A Group, we should all try to benefit from the collective knowledge and abilities of the members. I am more than willing to do whatever I can toward those ends.

If I made anyone mad with what or how I said anything, please click on the appropriate link in my signature. Also If you never have clicked on my links, I invite all of you to do so. Happy Trails.

 

Mine has a cracked case, but works. Want to dissect it?

 

Hell yes. They will fit in a large flat rate USPS box. I used to do failure analysis on Cruise Missile Parts and subassemblies for McDonnell Douglas as a Reliability Engineer. Before that I was a Manufacturing Methods Engineer and a Aviation Electrician before that. So I have a little different background than most people and a perspective that grew from those experiences in addition to being a true Southern Born Redneck.

I would love to tear it apart and see what it tells us.

 

Hey Danny, why dont you figure out how to rebuild these things and you could make some money.

 

Folks, I've got my '95 RR County LWB running by running a lead with a switch and a fuse from the battery to the excitation lead on the back of the alternator. Truck runs great with steady excitation voltage. Now my EE buddy Lew and I need to track down what vehicle wiring harness component is screwing up the excitation voltage (the alt is fine with voltage). Does ANYBODY have a wiring diagram? Could you tell me where the wire that goes to the excitation post on the alternator comes from? What is upstream?

HELP!

 

I would be happy to rebuild these alternators. Do not turn in an orignal MM for a small core fee, let's recycle them within the forum members.