What ND alternator will fit the GLH?

[ajakeski]

I'm running an underdrive pulley on the GLH and I've had the battery go dead twice now. I have the stock 78 amp chrysler alt on it now. Will a ND style 120 amp unit from a later model omni work?
Bolt on is preferred.
Thanks.

[turbovanman²]

Any ND non internal reg engine will fit-cars, trucks with the 3.9/5.2/5.9. Try a larger pulley, I had too.

http://www.turbo-mopar.com/forums/sh...ad.php?t=50896

[cordes]

Why would the battery go dead on account of the under drive pulley and normal GLH alt? Myself and many others have run that combination successfully. No doubt the ND units are better, but I don't believe your battery should be dieing from using the Bosh in combination with the UD pulley.

[turbovanman²]

Why would the battery go dead on account of the under drive pulley and normal GLH alt? Myself and many others have run that combination successfully. No doubt the ND units are better, but I don't believe your battery should be dieing from using the Bosh in combination with the UD pulley.

It doesn't charge very well at idle and if he's got a thumper stereo, the battery won't get charged.

[ajakeski]

No noisy stereo, just the OEM unit.
I don't know why it's not charging. I have to get on it with the multi meter and see what it's putting out. Right now I'm guessing.

[cordes]

No noisy stereo, just the OEM unit.
I don't know why it's not charging. I have to get on it with the multi meter and see what it's putting out. Right now I'm guessing.

That would be the first thing I would look at.

[ajakeski]

Field voltage is around 10 v all the time. Load makes no difference.
Charging voltage is around 11.8-12.

[turbovanman²]

Field voltage is around 10 v all the time. Load makes no difference.
Charging voltage is around 11.8-12.

Ok, so do this, undo your field wires, put one to 12 volts, then run it, ground the other terminal, if you don't get 13.5+ volts and low amps, you simply need an alternator.

[Turbodave]

It sounds like your field voltage is ok, should be around 5v with no load and 10v with a load on the system. I'm guessing that if the alternator output is low like your seeing the voltage regulator is going to keep trying to get more out of the alternator, thus the constant 10v. Was that measurement just at idle? If the issue was the underdrive pulley the voltage should go up once the engine speed is increased. Normally should be high 13.X low 14.x voltage coming off the alternator when it's running.

Has it been in traffic or idling a lot when it pulled the battery down? Any issues with the drive out to Belvidere and back the other day?


The ND alternators will bolt on, but they require a different lower bracket and some modification to the harness. I've also heard of some issues with the stock alternator wiring being able to have the current an ND can put out, so an upgrade to the main feed wire could be needed if you decide to convert.

[cordes]

It sounds like your field voltage is ok, should be around 5v with no load and 10v with a load on the system. I'm guessing that if the alternator output is low like your seeing the voltage regulator is going to keep trying to get more out of the alternator, thus the constant 10v. Was that measurement just at idle? If the issue was the underdrive pulley the voltage should go up once the engine speed is increased. Normally should be high 13.X low 14.x voltage coming off the alternator when it's running.

Has it been in traffic or idling a lot when it pulled the battery down? Any issues with the drive out to Belvidere and back the other day?


The ND alternators will bolt on, but they require a different lower bracket and some modification to the harness. I've also heard of some issues with the stock alternator wiring being able to have the current an ND can put out, so an upgrade to the main feed wire could be needed if you decide to convert.

Some of the water pump housings won't work with the ND alt bracket either. Jon Trotter's WP housing on his GLHS wouldn't allow it to bolt up for the ND unit.

[Turbodave]

Some of the water pump housings won't work with the ND alt bracket either. Jon Trotter's WP housing on his GLHS wouldn't allow it to bolt up for the ND unit.

Good point, the only L-body ND swap I've done was on a car that had a common block engine in it, so different water pump housing.

[ajakeski]

I found something else that could be part of the problem. The 14 ga. red fusible link by the left strut tower has most of it's insulation peeling off.the fusible link wire is intact, but pretty corroded. I don't have my manual with me, but I think it goes to the ignition feed.

[ajakeski]

Has it been in traffic or idling a lot when it pulled the battery down? Any issues with the drive out to Belvidere and back the other .

No problems on the way there, but on the way home the meter was in the red showing that it was not charging at idle. By the time I got home, it would not stay running with the lights and air on. I had to turn off everything to keep the car from stalling.
Once I shut it off, it would not start. All it did was click. Like a dead battery.
That's why I was blaming the alternator. Now I'm leaning toward the fusible link. I'll change it tomorrow.

[Turbodave]

I found something else that could be part of the problem. The 14 ga. red fusible link by the left strut tower has most of it's insulation peeling off.the fusible link wire is intact, but pretty corroded. I don't have my manual with me, but I think it goes to the ignition feed.

From your description that sounds like the power wire to the alternator (R6), here's the diagrams from the manual:

http://www.turbo-mopar.com/forums/ph...php?photo=6958

http://www.turbo-mopar.com/forums/ph...php?photo=6959

[ajakeski]

That's the one!
Thanks again for all the help.

[Turbodave]

That's the one!
Thanks again for all the help.

Cool, let us know if that solves the problem.

[ajakeski]

Fixed. 13.6 volts at idle with nothing running. 12.7 volts with the lights and air on.
I had half the engine bay apart to get at the wires.
Lesson learned for next time. I'm replacing all the fusible links while the harness is out.