Blinkers/flashers on 310 motorhome

[mayco]

Oh boy I need some help. My blinkers and emergency flashers are blowing a 15 amp fuse. This happened last fall on our last trip and stupidly I kinda forgot about it. I replaced the fuse last year and everything worked fine the rest of the way home. Really didnt drive it but maybe two times over the winter. Yesterday I took it out to fuel up for the up coming trip west to the Classic get together and the fuse blew again. I know that the flashers, blinkers, and cruise control are are lost when that fuse blows. So today I have replaced both flasher units, taken apart each light in the rear cluster and cleaned the sockets and replaced all the bulbs. Nothing obvious in the rear, some light corrosion in the sockets that I cleaned up with my Dremel. Took apart the two rectangular amber lights on the front and thought I had found the problem. One of those lights was wet and the bulb coroded to the socket. Got it out with some pliers and it cleaned up well with my dremel. I then blew it out real well with compressed air. So, with the new flashers in place key off, the hazards will blink about twice and the blows the fuse. The blinkers now do nothing, turn key to the on position, activate the arm and nothing happens, no blink, no fuse blows, nothing. The only difference is that I changed the flasher unit. Sounds to me like a dead short but havent seem anything behind the buckets or in the light that is obvious. Except that one with the moisture and corrosion but thats all cleaned up.....I know this really sucks but where would you guys go from here if you were me. Since the hazards blow the fuse I was kind thinking its not in the blinker switch but Im not sure about that. Cant make the trip west without getting this resolved ASAP.

Need help on where to go next on this.....what would the electric gurus do here.
Other than this the rig is ready to go......DOG GONE IT!!!! HELP, please, pretty please

[mayco]

If it means installing something temporary Im willing, really looking forward to this trip to Colorado for the get together AND see both my kids out there. Like those old units that clamped onto the column we used to put on old chevy pickups.

Mike

[mayco]

Which bulb in the rear cluster is the turn signal? I cant remember, I always have my wife in back when we do a lighting check.

[robert claus]

Just thinking out loud, but can you remove all the turn signal bulbs, then replace them one at a time and test the system each time to maybe isolate the problem to one corner?

[mayco]

Im not sure, I dont know if it will operate with bulbs removed. Hey good to hear from you Robert, youre headed across the pond here soon arent you?

[mayco]

I may give that a try here, see if it blows with no bulbs. Then like you said.

[mayco]

The brake lights and running lights are working

[mayco]

Made some headway thanks to Roberts suggestion. Pulled all the bulbs turned on the hazards and it began and continued to click the flasher. So I put each bulb in one by one and sure enough the one up front that was in the worst shape was the culprit. So the hazards are working except for the one.

The blinkers are still nada. Put a meter on each terminal where the flasher unit plugs in and I get nothing. No voltage. With or without the signal switch turned on.
The hazard switch flasher terminals were hot on one side regardless if the switch was on or not. So it looks like no voltage to the flasher unit for blinkers.

Does anyone know if there is a relay inline between the the flasher unit and the switch. Before I first changed the flasher units at least the turn signals were blowing a fuse, now nothing.......ANY IDEAS?

Thanks Mike

[Phoenix]

A couple of things to try:

• The cruise control is unlikely to be the cause. However, since it is easily unplugged, you might try disconnecting it, just to rule the cruise control out.
  
  
• Check the blinker/flasher that you bought to make sure it is the correct part for your motorhome. There are several types: For one of them, the flashing speed is determined by the amount of current drawn; and if a bulb is burned out, it will usually blink slowly or not at all. Another is designed for towing, and the blink rate is determined by an internal resistor (or probably some electronic circuit, these days); and it will blink at the same speed, regardless of whether a trailer, toad/towed, etc. is connected to hitch wiring or if bulbs are burned out. Just guessing, but you probably need the second type.
  
  Also, if you have some electronics experience, you might want to measure the current draw at the terminals for the blinker/flasher socket that drives the turn signals. For a circuit with a 15 amp fuse, you should measure less than 15 amps. If you have a second blinker/flasher for the emergency flashers, I'd check this one, too.
  
  
• Replace the bulb socket that was corroded. There could be some metal flakes or contamination that are causing a high-resistance or intermittent short.
  
  
• Check all bulbs to ensure they are the correct ones for each application. Incandescent bulbs come in several types: A dim bulb for running lights, a bright bulb for turn signals and brake lights, and perhaps a really bright bulb for who knows what. All of these may be similar in size and have the same base, but the current draw (amperage) can differ significantly. If you have a brighter bulb than is specified for a socket, you could be drawing more total amps than the circuit is rated for. This can happen if someone substituted a brighter bulb than was necessary; perhaps, because that's all they had at the time, or they didn't realize that it was the wrong replacement bulb.
  
  
• Replace the 15 amp "standard" or "fast-blow" fuse with a "slow-blow" fuse with the same amp rating. If there is a spike when the lights are switched on, this may allow the fuse to survive a brief surge in current. However, even if this works, you probably still have a problem somewhere; as the fuses for a circuit are usually spec'd at a slightly higher amp rating than is actually necessary, and a regular fuse should work OK.
  
  
• This is an expensive bandaid: Replace a few of the incandescent bulbs with LEDs, until the fuse doesn't blow. This in no way fixes the problem, but it might allow you to temporarily use your motorhome until this problem can be properly troubleshot and repaired.

[Phoenix]

An additional thought:

Troubleshooting often boils down to "what changed". If your lights were working, and then they suddenly quit -- what changed?

If you can recall the moment when they stopped working, do you remember doing something or anything happening at that time?

For example, did you install or replace any lights, sockets, or bulbs? Any small fender-benders, drove over a big rock, or backed into a post?

Try to think back and remember if something happened, something broke, or you repaired, modified or replaced a part. You may recall an incident that will clue you into where to look for a shorted wire or something like that.

Just a thought...

[robert claus]

If the trip is imminent, leave the one bulb out and go without a turn signal on that corner. Figure it out later when you have some time. Make Lynn a sign with a big arrow that she waves out the window every time you need to turn in that direction.

Headed to Austria in June. Planning to get some Camping in before then - maybe down your way!

[mayco]

Thanks for the ideas Phoenix. The flasher I bought is a 552 which was what was in there but who knows if it was correct to start with. Searched quite a bit on line and the results were a bit inconclusive as to what should be the right one. Same one in the hazards and they are working now.

Robert, yes. I have no problem driving on this trip with the one socket not working and if it comes down to that I will. I can probably find a replacement though.

So I got the hazards working but the turn signals are not doing anything. I measured 0 voltage at terminals of the flasher unit. If the flasher is after the turn signal switch maybe a bad switch? The hazards had 12 volts at the flasher terminal with the switch in the off position so I was thinking that the turn signals would be the same. But Im getting 0 volts at the turn signal flasher terminals.

So I guess my question is what do you think could be causing no voltage at the turn signal flasher. Is this the sign of a bad turn signal switch? Im no longer blowing the fuse, hazards are working, but the turn signals are doing nothing. Is there anything inline that could cause this or should I replace the turn signal switch.

[mayco]

Well I found and hopefully cured the problem. First of all the hazards and the turn signals are on 2 different circuits,
I didnt realize that. So TWO fuses had blown not just the one.....duhhhhhhh. The culprit for both though was the same. It was both of the little front side lights right behind the bumper on both sides. I guess I didnt realize these were turn signal/hazard lights. There are two on the rear also, front amber rear red. Took those apart and the sockets were toast, both of them. Looked like moisture. Will have to find replacements but for now I just removed the bulbs. Upgraded the flasher units to electronic rather than the cheapo thermal that I had bought yesterday. Let the flashers and both sides of the turn signals run for 5 minutes each.....YEEEEEEHAWWWWWW. Feel kinda stupid but 12 volt systems drive me nuts. Im much better at diagnosing 120v than 12volt. Oh well, got r done thats what counts.

[dadstoy]

Awesome job Mike. Glad you got it fixed. Great info for the rest of us when this happens in the future!

[mayco]

Thanks for that Dean. With every trial there is a silver lining right? First if all it happened at home and not on the road to Colorado. Second, Ive now gone through all those light sockets and cleaned them all up and replaced all bulbs with new. Third, if indeed it helps someone else down the road then its all worth it. I believe that if I look hard enough at just about any situation I can always find SOMETHING to be grateful for. (Even though at the time Im rapidly filling the cuss jar)

[robert claus]

Have a great trip!

[mayco]

You too Robert, that sounds like a really great trip to europe, AND you get to see a road race!!! Too cool

[tevake]

Way to rally guys. This a great thing about this forum, lots of diverse knowledge and willingness to share it.

Electrics is all smoke and mirrors to me.

Glad you got it sorted Mike, good work!

See you in Colorado, soon. :-)

Cheers Richard