Hello All I hope this is the right place to post. Ok here goes. I have an older 1985 Beaver 36 motorhome it is a DP. The issue i am having is with the tail lights running lights brake lights. Head lights work, blinkers work both front rear and sides. No running lights front cap rear cap or sides. I tested each wire going to the brake lights and every one seems to have continuity to ground. even the blinker.
According to the wireing diagram i have the following shows
there are three tail lighs on each side.
looking at the back of the rv
right lite set is a follows
right tail/turn/brake = red, brown, white
center light backup = black, white
left tail/turn/brake = yellow, brown, white
right tail/turn/brake = red, brown, white
center backup = white, black
left tail/turn/brake = yellow brown, white.
White is ground.
all wires show continuity to ground. I am asuming this is due to the lights beeing in the sockets? please help
Thanks for all the info. My fused are the old style not glass but rectangle cubes. with post. I have tested all the fuses and there is continuity and 12 v across them all. I have also replaced the light switch. an old GM style and validated power transfers across the correct connections. the prior owner had the headlights connected to the first pull on the switch. witch i corrected to the second pull. I also validated I had power +12v tot he relay coming from the light switch and power. The relay also clicks and and transfers 12v to 87/87 since this is a dual 87 relay hope that makes sense. I will try the other recommendation you have very good info. I am somewhat teki. but its been a while.
It sounds like you have a standard Bosch type relay?
If it has 87 and 87A, the 87 is the normally open relay contact which is switched to closed by the relay's magnetic coil. 87A is the normally closed contact which is opened by the action of the relay's magnetic coil. Some of these relays do not have the 87A contact because this is not required for the application.
In case you are not aware of the operation of these relays, 30 is the common (moveable) contact which is switched between 87A and 87 in order to complete or open the circuit.
85 & 86 are the magnetic coil terminals. If the relay "clicks" in response to the operation of the headlight switch, then it is almost certain that the relay is moving the contact 30 from 87A to 87. You may wish to ensure that you have power at 30 and that 87 is powered when the relay is operated (clicks). If your application has the 87A used, this would be unusual for operation of the running lights.
You may also wish to do a simple but relable test by unplugging the relay and connecting a jumper wire between terminal 30 and terminal 87 which should power the running lights. If it does so and the relay clicks when the switch is turned on and off, it is quite conclusive that the relay has failed contacts or other internal circuit issues and should be replaced. This is not a unusual failure.
Thanks for mentioning the presence of the relay as I didn't recall the use of a relay as OEM on GM chassis vehicles of that age range.
Hope it is solved but otherwise will check back to see if anything else can be offered.
Continuity to ground will be normal as you stated. If you are using an ohmmeter to identify that the circuit is grounded, the reading isn't a reliable indication that the ground circuit is useful to the load. In the trade, we never use an ohmmeter for this purpose, JFWIW.
No running lights means: no power to the headlight switch, a problem with the running light circuit within the headlight switch, open circuit in the wiring between headlight switch and lamp sockets, poor bulb connection in the lamp socket, or open circuit in the ground. I'll go the long way around on this as it is generally better to have more information than less.
Since you have several/all running lights not operating, it is reasonable to assume tha the problem is not a ground issue because the lights ground to separate locations. I have seen a few trailers and motorhomes where sections of the body skin no longer made connection with their neighbor or the attachments but this is unlikely for all.
Assuming that you have a voltmeter?
First place to check is the fuse box, but imagine that you have already done so?
Just in case, take your voltmeter and check for power between ground and each of the two fuse clips which secure the fuse. This must be with the headlight switch on. If you have power at one end and not the other, the fuse is open/blown despite that it may look good. Test for voltage between the two ends of the fuse. There should be less than 0.1 volt between the two ends of the fuse.
If there is a decent voltage (say 10 volts+) between either of the fuse end clips and ground, then it is safe to assume that there is power to the fuse and that the fuse is good.
I assume that your rig has the older style glass "Buss" fuses as these are most common for that era. If not, the same tests are valid.
Next step is to access the headlight switch which I think is in the dash to the side of the steering column on that era rig?
Another assumption if that you have owned this rig for some time and know that someone has not installed an extra switch to allow the running/tail/clearance lights to be switched off separately? People do all kinds of things, sometimes for silly reasons and sometimes for excellent ones which we do not recognize.
If you know how to remove the headlight switch, then drop it out and check for power across the tail light switched circuit. If not, post back and someone can describe removal.
A "RV park emergency fix" could be to use a jumper wire with 15 amp fuse to connect from battery + to one of the park light/running light/tail light/clearance light wires. In this event all these lights should come on. Do this with the headlight switch off. If all these lights come on, then you know that the circuit between all junctions and the lights is in existence so the problem will lie before the last junction.
You can do this additional, "RV park" test without pulling the headlight switch also: with the fused jumper wire still in place and the running lights on, operate the headlight switch to the running light position and check for voltage at the running light (park light, tail light, clearance light, what ever of these names they happened to use on your fuse box) fuse to ground. I expect that there will not be power or your previous test showing that there was no voltage at this fuse is incorrect.
If there is no power in the last test to the fuse, the lights work when
jumpered to power, you will have to pull (remove) the headlight switch to determine whether the problem lies in the switch (likely), between switch and the first wiring junction point (likely) or between the switch and fuse box (less likely).
I find that this becomes too much for people so advise as to results, indicate where you require clarification and will try to help further. This will seem like a more involved process than it is because you are unfamiliar with the system but take time and you can get there. There are "work around" solutions, and other possibilities if the problem is an open circuit such as a broken wire within the wiring harness between headlight switch and the junction point.
It is sometimes more practical to connect a new wire into the circuit at a more accessible point but this needs be done properly.
This is an 87/87 not 87/87a both 87s are tied together not like the 87/87a where it switched from 87 to 87a both 87s are powered at the same time. power does transfer when power is supplied to pins 87.
Pin 86 ground tested good to ground. pin 85 test 0v then 12v when light switch in pulled to position 1 or 2, pin 30 test 0v then 12v when light switch moved to position 1 or 2. first pin 87 has two wires second pin 87 has 1 wire. all are brown. brown single wire is saposed to supply power to TM/ICC lights I.E. Tail lights second brown to same pin goes to front cap and rear cap ICC lights. Single brown goes to front running lights. this is according the the wireing diagram I have. Thanks I will br trying some of the RV Park tests. tommarow.
What voltages are you showing at the 87 terminals?
The relay is wired in reverse to that typically used as 30 is usually to power (12 volts +) with 87 being the load or lights. This is not a problem as the switch works the same way regardless but am intrigued by all the wires on the 87. It seems that the relay is operating correctly as 30 is not powered until the switch is operated and then it is powered.
I don't think that the "RV Park" tests will take you further than you are because I was suggesting these in case you were not able to use the meter tests. We seem to have a difference in how we label that someone is not electrically experienced as you clearly understand testing procedures. Sorry for so many details as thought you were working from a much more basic level.
It would seem from your test results that 30 is being switched as it should be. I just want to confirm to ensure that I am not misunderstanding:
30 does show power of around 12 volts when the headlight switch is on in either park or headlight positions? If it has power when the light switch is off and then drops to zero when the headlight switch is on in either position, the 30 is powered from 12 volts + and it has a bad connection/high resistance.
I don't want to lead you in the wrong direction as is so easy to do by remote.
If my understanding is correct, there would seem to be an open circuit between 30 and the first running lights (park, tail, clearance). It may be possible to physically trace/follow the wire while looking for a damaged area, connection or splice which can be opened up to check for voltage/corrosion.
Have to go as driving DW to medical appointments but will check back later when able.
I did a quick search for "Scotchlok problems" and this is the first link which came up: http://www.youtube.com/watch?v=PAgrevpkKJs
Haven't had time to watch through but it does show the type. The point is that these things should be avoided like the plague! Vehicle wiring usually has some exposure to moisture and since these connectors are both open and make only small area contact, they are prone to problems. Sealing them is difficult and makes for bulky connections which have relatively poor area to conduct power.
Look, especially, for one or more of these as you trace the wiring. They are typically installed by home do-it-yourself trailer wiring installers and any electrical specialist will relate what a huge problem this is. They turn to rotten junk on no time.
Not a problem with all the details, it good. Like i said its been a while since i have applied them. Yes 30 is being switched as it should be when the headlight switch is pulled to running lights. Postion 2 on the head light switch would be running lites and headlights. No problem on the the label confution. I kind of look at it both ways. ICC lites to me are non blinking lights like the roof caps side markers. Tail lights brake lites and blinkers to me are tail lights front lights not head lights. I look at them as running lites.
Again thank you for your help you have helped quite a bit. I am still going to run the RV test. I already started to trace the wired from the front of the rv but there run up inside the front pillars and there is no way to access them from there. This is one of those cases where they guy I got it from just did a few things to just make them work. and i'm trying to fix them right. I am also looking for any switched that may have been installed under the dash or anywhere else that may be affecting it. I just don't see someone installing a switch so the brake lites don't work. FYI I also tested and replaced the brake lit switch in the brake peddle it was bad