surging voltage

[dodgeville]

Our 1969 dodge travco 22 footer with the 318 semi hemi is doing a rythmic power surge. Does it at idle and under power. The lites dim and brighten with it. I've put a new voltage regulator on and checked all connections, especially grounds. Rig is all original with the ballast resistor and original distributor.
Any ideas would be appreciated. Oh and I've tried a hammer already.ha

[Rich Thomas]

I think Id pull the alternator and have it load tested. most auto zones, o-rely and advanced stores will test them for you. it sounds like a bad field winding or segment. Something else you can look at is ( and this may seem stupid but) check the v belt for ware. It may just have a worn spot that slips each time around. Many a good battery has been trashed because of faulty or loose alternator belts.    

[jeff york]

one more thing. Most alternators have a single wire charge lead. Its usually about a 10 gauge wire. Very important for this wire to be perfect. 

[jeff york]

Do you have an alternator or actually a generator. Most alternators , I believe all modern alternators have a built in voltage regulator by way of a built in bridge rectifier. I say I think because I do not know all alternators out there. Assuming all your connections are clean and with out corrosion and very tight ( I suspect a ground wire issue) then as someone already mentioned, it sounds like a worn out alternator. yours is a 69 so I am still suspecting a corroded connection even with a new regulator. did you clean all of the connections ? The problem as I see it is with all of the testing you do you may be looking at continuity and voltage but that wont help if your issue is current load and with surging, that sounds like a current load issue. What is the rated current ( amps ) output of your Alternator ? is it putting that out ? Have you added anything to your systems that requires a greater current draw then your alternator can provide ? Have you tested or had you battery(s) tested under a load test to see if you do not have a battery that has a bad cell causing an excessive draw from your alternator ? Are your battery cables # 2 gauge or larger from battery to end point with no splices or interruptions ?  It only takes the very slightest of loose or corroded connections on a high amperage system to cause a dramatic increase in circuit resistance which will cause electrical issues. Test each battery cable for battery to end point for OHM resistance. There should be no more than 1 ohm of resistance. If there is, replace it. Assuming again that it very tight. I just got a great refresher in all of this with my electrical issues and it caused me to get the cob webs out of my over assuming many years experience as an electrical engineer. I elt pretty stupid in the end after Rich reminded me over and over to go back to the battery and the cables especially the ground and work my way forward. I found a hidden splice in my #2 gauge ground wire that was tucked and hidden away. I assumed a lot of things and that only caused me issues. 

[R. Randall Halton]

I have no idea. Could there be something wired into the power line somewhere or a possible miss wiring. What I have found is that the Travco web sites seem to refer to the Mopar web sites for OEM technical info about wiring/electrical & power train. What is sad is that most of the expert mechanics pre-ECM era are passing away. Any of the Mopar mechanics know just about everything about these issues. And most knew of the Travco coaches intricacies and tricks of various issues. I'm going Cummings on my 270 & I know nothing about diesel. Check the MOPAR sites, allot of interesting topics on the 318.

[Russell E Johnson]

Hammer -- ROFL it is my first choice also.  Anyway, is the regulator connected to the alternator or separate?  If separate, you may have an alternator that is going bad.  At idle and under power there is most request for power whereas at a steady speed there is minimum request for electrical power.  Check the output of your alternator and see what is going on there at idle and at a higher RPM.