ROG100

Alan,
Just for the record this is a Bosch Premium remanufactured unit not a rebuilt unit, big difference - "Bosch Professional Preferred Remanufactured Alternators are built especially for extremes of heat, cold and high demand. They are built to last using the highest quality materials and the most technologically advanced processes. Every component is 100% factory tested prior to and during remanufacturing to assure that it meets or exceeds original equipment specifications. And all units are full-load tested to guarantee compliance with Bosch's strict performance specifications."

Now, as you know, I am not saying it is not a bad one as that can happen, we will see when we fit another new one.

If this were an alternator that had been rebuilt - tested and only a small number of the parts replaced - I would accept that it was the alternator. We have now had the same failure with two alternators and about to fit a third. Three with the same failure mode would be strange me thinks.

Just thinking out loud.

JP Rodkey

The problem is in the wiring - likely engine harness as Jim Bailey suggested, IMO.

84totheFloor, check your PM's.

Alan

It seems to me the exciter wire works correctly except when its connected to the alternator. That tells me its less likely to be the wiring. However there have been many confusing readings measurement methods etc and its all a bit fuzzy trying to decifer whats what.

Tim given the previous "issues" with measurement methods it would be good to confirm the following.

With exciter wire disconnected from the alternator - measure the voltage on the dangling wire to chassis ground.

I think you have said at various times:

0v with ignition off
12v with ignition on
Ground the wire and the dash (non) charging light comes on

Correct? This is all normal

Seems the oddball stuff only happens when the alternator is actually connected.

Alan

85fortheDrive

I spoke with Andre about this. I think it would be cool if we could pool some time, talent, and resources to find a way to make NEW pcb's for our cars.

JP - It was great to speak with you. At present, I concur that a faulty alternator is quite unlikely and that the 1-pin blue wire from the jump post harness should be investigated. Just had a TB job done on the car and so I'm curious about wire harness components overheating and changing their resistance.

Alan, the above is all correct - with wire NOT connected.
When I connect the exciter wire to its terminal, I get 0.25V with key out and with key to ignition point.

85fortheDrive

With the second replacement alternator due in from (ever-generous) Roger tomorrow, I ran a few more tests this evening.

I popped the plastic top off of the wiring harness at the jump post and found almost 0 ohms of resistance through the exciter wire from there to the alternator. Thanks JP for that suggestion. Note that the wires are cold at this point.

I then reassembled and reattached the alternator, leaving the intake hosing off, and started the old boy up. For the first time ever, I actually saw 13.5V on the gauge! I ran the car for about five minutes, revving to 2K rpm and turned the lights on. Voltage dropped to about 13V then. Then I shut the car off and restarted it. Same readings for five minutes.

Still some tests to do, but it seems like the car is feeling a bit better.

Too early still for excited icons, but I was happy.
Continued thanks.
Tim

j.kenzie@sbcglobal.net

Sounds like a good start. Looks like you'll have to give it 60 minutes of running to see if you can reproduce the old failure pattern. Maybe you fixed something. I must admit, Roger's alternators sound like good units. Good luck.

Alan

So finally this sounds like about the correct behaviour (not sure on the 0.25v with key out...) - but what changed...??

Keep us updated about long term driving results...

Alan

85fortheDrive

This is the pudding in which the proof will be found. I hope to get the OB out this weekend to see how things behave after the engine and wires start to heat up.

I do think we're getting closer to driveability because we're due to have snow this evening.

ROG100

Tim,
I've got my fingers crossed you have fixed it.
I see the second alternator arrived in time for Turkey 8>)
I will be open for calls tomorrow - just do not expect me to answer when the COWBOYS are playing.
Roger

85fortheDrive

Roger,

I am going to return to the OB on Saturday, with the intention of leaving the current new alternator in place. Your second new one arrived today as you said. I'll leave that in the box until I get the old boy out for a decent spin.

I will be rooting for the Packers and Cowboys tomorrow. The only call I will make to you will be to wish you and yours a Happy Thanksgiving.

Peace,
Tim

85fortheDrive

Got the OB back on the road today. Seem to be getting a pretty consistent 13V. Still has Roger's first replacement alternator in it.

Interesting note. The central warning system now works for the first time. It never activated before.
The seat belt light comes on now too; never before.

I have always had a Tail Light indicator come on when the headlights are turned on. Still does, now accompanied by the central warning light. (I get to push the ! button to deactivate the warning light now.)

So I decide to see what the deal is with the tail light. I remove the two back side lights and pull the ground wire off of one of them. Then I turn the key to the second position and WHOA, the alternator light does not come on. When I start the car, I get only 10V.

This is indeed an interesting electrical system.

Thanks again sooooo much!

Mrmerlin

your light problem will most likely be either of these first check all of the grounds, Second make sure that all of the bulbs are matched from side to side and that they are of the correct rating, usually indicated near the bulb receptical, also make sure the side marker lights all have the same bulbs.