Bad turn signal switch or something else? 1971 D22 Electrical

[Wilhelm7]

Situation: The 4-way flashers work except for the right front lamp. However, with the 4-way switch off, the right front and right rear turn signals work, but the left side front and rear don't work. BTW, some PO spliced in a fuse block/flasher socket to add to the mess behind the kick panel. Any ideas? Is this a typical occurrence in these rigs? The wires appear to follow the color code on the wiring diagram. I can get a hot rod turn signal switch from Amazon for $20 if need be. Thanks in advance. 

[Rickf1985]

It is going to be impossible for us to diagnose online due to the added circuits and not knowing why or where they go. The main problem I have is that you are working with the same wires and the same bulbs for both the 4 way and the turn signals unless they rewired the entire coach. That R/F turn signal works on the same wire and bulb as the R/F 4 way so they should both either work or not work, one or the other. You are going to have to trace out the added circuit and find out where it ties into those wires out to the lights. And try to figure out why that circuit was put in. I used to love the challenge of these jobs when I had my shop but then again, it was right there in front of me, much easier to diagnose when I can trace the wires in person.

[Wilhelm7]

Rickf1985, It looks like the original wiring schematic shares the bulbs. The service manual warns about potential feedback and says have no other 12v appliances on with the 4-ways. It's one surprise after another with this old beast. Thanks for your advice.

[legomybago]

I've been thrown through loops trying to figure out some "mystery" electrical issues kinda like you are describing, and it can be a bad turn signal switch. Test power coming out of your steering column/turn signal switch and trace it from there. That's where your signals originate from anyway....

[Wilhelm7]

Some PO, for whatever reason, ditched the original rear turn signal/brake light fixtures and installed red-yellow lens units that I suspect were intended for a system having separate brake lights and turn indicators. PO wired the red and yellow in parallel. Could the extra load of an additional bulb be causing problems? Whichever, I intend to remove the bulbs from the yellow lens sockets. Thanks anyone.

[Rickf1985]

The extra load would not cause any issues like that, all it would do is cause the flasher to flash faster if you do not have a heavy duty flasher. If that was "ALL" he did then the problem lies elsewhere. But make sure that from side to side the wires are tied together only at the turn signals for that side and not across the two sides.

[legomybago]

Some PO, for whatever reason, ditched the original rear turn signal/brake light fixtures and installed red-yellow lens units that I suspect were intended for a system having separate brake lights and turn indicators.

This is another clue that you may have turn signal switch issues...Usually when you see a rig with "after market" rear tail lights installed, is because they were having issues with the switch and didn't know it, then they tap in some funky lights to bypass the original setup which causes issues elsewhere...I've been down this road fixing someone else's junk.  W% Start from the beginning. Test power coming out of your steering column!!

[DaveVA78Chieftain]

Based on the Dodge Service Manual wiring diagrams, Dodge did not provide hazard flasher circuit on their motorhome chassis until 1972.  So, you first need to check the signals from the turn signal switch (LF, RF, LR, RR) at the base of the steering wheel.  The aftermarket hazard switch would have been in integrated after that switch.