Just purchased an RV... with 22,201 original miles. Yes, it is true miles... we were first to see it when it got posted on Craigslist. All stoked, but...

1) Electrical gauge bounces back and forth, from the middle of the gauge to the far right ("okay" to charging maximum). It never reads in a Discharge position when the engine is running.

2) ALL lights flicker, in an "on-and-off" mode, while the engine is running... whether at idle or under load running down the road.The lights do not actually go completely on and off, but have a noticeable flash - as if you see an ambulance heading in your directing with "wig-wag" style headlights operating, and the interior has a mild disco lighting effect happening.

3) At the battery, with the engine idling or revving, the meter will read between 14.7 and 15.4 volts (fluctuating rapidly - as if to the beat of the flickering lights).

4) The battery is brand new, and reads 13 volts when the engine is off (oddly enough, the alternator appears to be about the only item replaced on this van)... Auxiliary RV Battery also reads 13 volts.

5) Cannot locate any problematic wiring (loose grounds)... in fact, all wiring appears to be undisturbed, without anyone having altered anything.

6) "Oh, it's gotta be the Voltage Regulator"... sweet, but this van no longer has an external VR (I am told 1986 was/is a "changeover" year).

7) All other electrical items work properly (Dash A/C, Radio, Horn, CC, PW, PDL, Exterior lights)... EXCEPT for turn signals/ flashers which failed two nights ago - when this issue cropped up [maybe just a coincidence?] (will replace the flasher this a.m.).

7) Before I remove and replace the alternator, can anyone else (with more electrical experience than I) say that I am chasing the wrong cat up the wrong tree?


Thanks for all of your input...


351 V8
4 BBL
Automatic
[Group 65/ 1000CCA/ Costco] Single Battery setup for the chassis
Auxiliary RV Battery, located in rear of van

 

Check for a battery isolator between the alt and the batteries.

Follow every last battery cable, put your hands on every inch of every positive cable. It may be rubbing through somewhere. I mean it.

Test alternator in chassis. Take it to autozone, they have a reistance/load based tester that is quite good. You can also just connect a voltmeter up to the battery terminals, it should not pulse up and down. If/when you DO pull the alternator, have it tested on the parts stores machine before just buying a new one. If you are gonna drive the RV a lot you might want to look into upgrading the alternator to a 3g alternator. They catch fire less often. You CAN have an externally regulated alternator if you have a 351W with the high output alternator option.

I just remembered. To pull the alternator you MIGHT have to remove the radiator. There is a long bolt that gets in the way.

 

Before I go any further I will have an Auto Electrical Mechanic check it out... there is an old guy here in East L.A. (I think it's "Lenko's") that knows his craft.

I'm not an expert... he found a short in my steering column on an '85 FJ60 that I had... in less than 2 hours he had me picking it up (I can bet the bank that Toyota would have spent many more hours, and charged me a wad for the same). The rig would simply die on the freeway - without warning. I would have never guessed to look at the steering column for resolution.

I will upgrade... but at a later date... considering something like the "Green Machine", or whatever it's called... along with a third battery. For now I want to keep it stock - and as simple as possible.

To further the symptoms/issues... when the vehicle is OFF there is zero flickering. Though I have yet to thoroughly check out the Battery Isolator, I have tried to check all connections, where I can locate them.

There is no apparent drain... the flickering only occurs when the vehicle is running.

I keep coming back to the internal Voltage Regulator... but, again, I'm no expert. Thanks for your input/advice.

 

Pics of said vehicle or this all happened in a dream that started out wonderfully and ended, continued, ended, continued, ended, continued..........

 

Okay Rico...

Yes, it exists...

No, I can't do the pics yet...

A) Because someone has "fixed" my computer - and now I can't simply download the SD Card.

B) Because someone has stored my camera's computer cable - for safe keeping - in God knows where-land.

C) Someone will be picking up a new cable for my computer or someone will find me really making a mess everywhere I go around this house.

Anyways, I will be posting pics ASAP... It really is - almost - as nice as the low miles indicate. Save for the typical sun wear on exterior surfaces it is as pretty as they come.

Would love some more input on this alternator issue...

 

Sounds to me like the alternator has a bad diode in it. Getting it checked out at an auto parts store would let you know.