I have a 1990 5.9 Cummins from a 91 Dodge. I installed it in a 72 GMC truck.

When I,m driving the headlights and the cab lights "pulse". The pulsing is faster with RPMS.

I checked the Alternator and the brushes do not appear to be worn.
I installed the Voltage regulator from the Dodge donor truck.
I double checked and added a few more grounds from the engine to the cab and the cab to the frame. The engine is already grounded to the frame.

I understand this is a common Dodge problem. Anybody know the cure?

A Diode problem in the alternator?

Thanks

How would I check the Diode? Set the meter on AC I assume or is it after the conversion to DC?


I don't know diddly about Alternators.

Read this:

http://www.pirate4x4.com/forum/showthread.php?t=512783

Read this:

http://www.pirate4x4.com/forum/showthread.php?t=512783


Thanks for the heads up.




If you follow the links, Dodge is an option, the next option is Tech Talk.


I have asked a moderator to move this to what ever section it is supose to be in.

Sorry about posting in the wrong section.


Who "Hardcore" Wheels a 100% Dodge Vehicle?

I know when my grid heater comes on and and off in my 98 CTD, the lights pulse - but not with RPM...

I think I'll move this to the tow rig forum, that's probably your best place to get a good answer.

Who "Hardcore" Wheels a 100% Dodge Vehicle?

A lot of us do. Actually hang out in the Dodge section and youll see. As far as pulsing lights, my 85 gasser does it too so ill be watching this thread.

Duane

Thank You.


I think I'll move this to the tow rig forum, that's probably your best place to get a good answer.


Here is a picture of the rig.

72GMC Sierra Grande 1-Ton 4x4.

Cummins 5.9 from 1991 Dodge Truck.
Getrag 5-speed
NP205
Dana 60HD up Front with 4:11's.
Dana 70 U in the rear with Detroit locker with 4:11's.
35" Procomps.

It is not 100% done yet.I have to rhino line the bed. Finish putting the chrome on, get a few wiring gremlins figured out, etc.

Try a new voltage regulator?
Disconnect the intake grid heater relay and see if it still does it?

Its a Dodge regulator thing Dan.... You can try a different reg with better/worse results (hit and miss) to try and make it better. Also, try running a different battery and see if its better. You may have a weak one. Ive got a spare alt if you want to try that as well...


Chris:cool2:

Thanks

The regulator seems to have a special conector on it. Is there a better/different regulator I can get? I went to the auto parts store and they refered me to a Dodge dealer since they would not take back electrica stuff. The dodge dealer asked for my Vin#. :eek:

I'm running dual redtop Optimas that were bought new together about 8 months ago.


Its a Dodge regulator thing Dan.... You can try a different reg with better/worse results (hit and miss) to try and make it better. Also, try running a different battery and see if its better. You may have a weak one. Ive got a spare alt if you want to try that as well...


Chris:cool2:

when it comes to cummins you always have to have the VIN or the block number for them to hunt down parts. I cant say I had this problem on my 92 but your 72 retro tow rig is BAD ASS Looking

Thanks

The regulator seems to have a special conector on it. Is there a better/different regulator I can get? I went to the auto parts store and they refered me to a Dodge dealer since they would not take back electrica stuff. The dodge dealer asked for my Vin#. :eek:

I'm running dual redtop Optimas that were bought new together about 8 months ago.


Is the regulator connector triangular shaped with two wires going into it? (A Green and a Blue?) If so, the blue wire is hot with the ign. telling the regulator to turn "on" and the green wire is the ground side of the field windings in the alt.


Again, if you want to try a couple other parts to see if it can be better your welcome to what I have. (Try a fresh battery first...)


Chris:cool2:


Edit: just re-read that you have new batteries. Try disconnecting one and see if that helps just for giggles.

Is the regulator connector triangular shaped with two wires going into it? (A Green and a Blue?) If so, the blue wire is hot with the ign. telling the regulator to turn "on" and the green wire is the ground side of the field windings in the alt.


Again, if you want to try a couple other parts to see if it can be better your welcome to what I have. (Try a fresh battery first...)


Chris:cool2:


Edit: just re-read that you have new batteries. Try disconnecting one and see if that helps just for giggles.


Thanks

I may just come up to your place and try to de-bug this. It is going to be something really simple that I am overlooking or something really strange.

Well I found out that the alternator it is putting out 19.8 volts when checked correctly :eek:

I guess I did not know it was internally regulated and I hooked it up through a regulator. The Optima Red Tops took most of the abuse and are holding up well.


A Diode problem in the alternator?