Turn signal problem

[Michael Oritt]

I am having a problem with the turn signal circuit on my BN1. A little background info: First, the flashers are energized through their own fused circuit separate from any other load. Second, several years back I installed bulb holders in the rear reflector pods and ran the turn signal wiring to them. In other words the stock tail lights are only doing duty for running/side lights and brake lights.

In any case, when I activate the trafficator the front and rear turn signals and indicator light on the dash work, though they blink fast--about two times per second. And invariably after 10-15 minutes of driving the fuse blows and the turn signals become inoperable. When I replace the fuse the signals work again but after a few more minutes of driving the fuse blows again, ad nauseum. This happens with all size fuses up to 30 amps, so clearly something is going to dead ground.

Thinking that the problem might be from the wires in the steering column I have jacked the car up and turned the steering wheel from lock to lock while the signals are on, but I cannot replicate the failure mode. I have also jiggled all the lights and wiring at all the fixtures and at the base of the steering column while the flashers were operating but--of ours--everything was fine. The fuse only blows when I am driving the car. I have not taken the fixtures themselves apart.

Obviously I am dealing with some intermittent short but prior to tearing everything apart I wonder if some listers can me suggestions on how to approach this problem.

 

[Keoke]

In any case, when I activate the trafficator the front and rear turn signals and indicator light on the dash work, though they blink fast--about two times per second. And invariably after 10-15 minutes of driving the fuse blows and the turn signals become inoperable. When I replace the fuse the signals work again but after a few more minutes of driving the fuse blows again, ad nauseum. This happens with all size fuses up to 30 amps, so clearly something is going to dead ground.

Well Michael an additional three things that come to mind here:

1] The duty cycle [ Flaser Rate ] is too high and over the
rest time interval the fuse can not cool. Consequently, it continues to heat ubtil it fails.

2] for some reason the circuit looks inductive and a standard fuse will not survive the average peak power generated in the circuit.

3]the applied voltage perhaps because of a faulty regulator may be going too high..

A potential solution to the problem might be to replace the fuse with a slow blow type----Fwiw--Keoke

 

[57_BN4]

You can use a spare indicator or headlight bulb with a couple of feet of wire attached for fault finding. Put an already blown fuse in the holder but trap the ends of the test-light wire under each end of the fuse and run the wire out of the bonnet so you can see the light come on while driving. The indicators won't work of course.

Instead of blowing the fuse, the fault will now light the bulb with no danger of damage to wiring as the current is limited by the bulb.

Pull over when the bulb lights up and wiggle around on things until it flickers or goes off again. Works a treat for narrowing down random faults.

Andy.

 

[RAC68]

Hi Mike,

My initial thought is that you are experiencing a Constant low lever amperage draw that is accelerating the heat cycle of the bi-metallic flasher switch and retarding it’s cooling. Eventually, the heat build-up within the flasher causes sufficient resistance to burn the fuse.

To verify, are you having the problem when setting the directionals to either side? If yes, and since the flasher is the source of power for either side of the directional system, I would look to a faulty flasher or a low level power draw in the trafficator or lines leading between. If you are experiencing the problem only when the trafficator is set to one direction, then the flasher box, bulbs/fixtures, and lines in-between are harboring your low level short.

Again, my thought is that you are experiencing a continuous circuit draw as a result of a hot line hitting a ground. I don’t think yours is a dead short so it must be one where current is leaking through thinly warn insulation. Also, is must be a location having constant power flow for the reasons initially presented.

No solution but I hope this helps.

Good luck,
Ray (64BJ8P1

 

[RAC68]

Hi again Michael,

Do you have the problem when the engine is not running?

If not, I am inclined to agree with Keoke in that your problem could be the result of Over Voltage. Since the flasher rate will increase from over-voltage and your fuse will only protect against over amperage, you should not experience a blown fuse upon initial activation of you directionals. Over a period, the fuse will eventually blow as a result of increased resistance caused by heat build-up within the flasher. At this point, a runaway regulator seems to be a good candidate for the cause of your problem. If you are experiencing the problem on both directional circuits, and if the problem only happens with the engine running, I would definitely do a fast running voltage check.

As an aside, I had cut the leads on my inexpensive multi-meter and installed spade connectors. This change allowed me to create a number of attachments (long lines, alligator clips, power take-off plug, etc.) that make the meter more flexible to use. I have used the power take-off plug, in a socket installed on my Healey, to monitor voltage levels when on a run. This had been very helpful in identifying a generation problem that turned out to be caused by hot-engine fan belt slippage.

Good luck,
Ray (64BJ8P1)

 

[Michael Oritt]

Fellas--

Regarding Ray's question as to whether this happens when the engine is not running: I cannot answer that as I have not tested that condition yet, but I am pretty certain that the dash-mounted voltmeter has not indicated more than 14 VDC during any recent drives, though I will double check this.

Yesterday I attempted to determine whether the problem would occur in a static situation with engine off and carried power to the wire that runs off the problem fuse, but apparently the control box or some other part of the circuit also gets power and the flashers would not come on. Tomorrow I will disconnect the fuel pump and electronic ignition circuits and then will be able to answer this question--certainly if the fuse blows while the cart is sitting still then Keoke's suggestion that the flasher is causing the problem would be likely.

As always thanks for the input and I will begin to address things tomorrow starting with the above test and perhaps changing the fast flasher relay may provide a simple fix.

 

[Randy Forbes]

As a quick <span style="font-style: italic">process of elimination</span> trick, try driving the car (as is) with the green wire going up the steering colunm disconnected.

That's the power feed to the trafficator switch.

In years past, I've seen a variety of shorted colunm wiring mysteries. The most boggling was the BJ8 that couldn't be shut off; the horn circuit (hot to the horns, with their ground running up the column) had shorted to the green wire, leaving the ignition circuit energized.

If you car still has the original (or even 70s era) column wiring, it's due for replacement.

If I can think of anything else, I'll let you know...

 

[1965AH3000]

1). Get a volt meter, and check the DC voltage across the battery with
ignition off (12.5 -13 VDC) and again with motor running at 2000 RPM
(13-14VDC). If you are within these limits give or take 1/2 volt your basic charging system is OK.

2). I=E/R so I= current E= voltage and R = resistance. Resistance is = to the filaments in the bulbs plus any poor connections. So, if the resistance stays the same and voltage goes way up, the current rises. A decrease in resistance I.E. a short or wire touching ground increases current.

3). You can purchase a small volt/ohm meter at Harbor Freight or other supplier
really cheap. I recommend any owner of an old car get one and learn how to use it.

 

[Keoke]

I=E/R so I= current E= voltage and R = resistance. Resistance is = to the filaments in the bulbs plus any poor connections.

Well yes 1965AH3000 that is true.

When a current is passed through a conductor, heat is generated, This is the principle which operates in FUSES.

So in this case we are more concerned with the heat { W } produced in the fuse which is expressed by:

W = I the current squared, multiplied by R the resistance and T which is time.

Therefore, if I and R remain constant, positive values , but allow T to be an increasing non zero variable, then given sufficient TIME we will eventually produce enough heat causing the fuse to blow.Fwiw--Keoke

 

[RAC68]

Michael,

The first thing I would do is try another flasher.

I am not sure how you have rigged your directionals but, in standard form, Power is directed from the fuse box to the flasher and trafficator. Since power for this application is drawn through the ignition switch, the key must be on (but the engine can remain off) to activate the directionals.

Since you have your rear directionals only presented through the reflectors, have you wired your rear lighting as per the BJ8P2 or have you redirected the directional wiring from the flasher relay box and wired your break lights from the brake switch?

If you are using the flasher relay box, as I suspect you are, and a horn short inappropriately powers the trafficator switch at either of the directional posts leading to the flasher relay, no problem will be indicated when switching the trafficator to the direction of the short but could create and electrical issue when powering the non-shorted side as you will be applying power to both sides of the relay. If the horn shorts on the center portion of the switch, the only change you will notice is that the directionals will work with the ignition key off (as the horn circuit always has power). If you have not noticed any of these odd responses, I would suggest that your flasher is faulty.

Good luck,
Ray(64BJ8P1)

 

[Michael Oritt]

At the suggestion of several folks I replaced the flasher with a new unit and as expected the flashing interval went back to normal--about once per second. Then, prior to taking the car for a ride I started the car and with the engine at idle I tested the flashers both right and left and everything was fine. BTW the voltage is 13.8 running--I have an alternator.

I then took the car out on the road and put the flashers on--both right and left side--and both cancelled them manually as well as by making turns both left and right. After about five minutes of running when I went to put them on again the flashers would not come on. I pulled over and checked the fuse and it (15 amps) was blown. Though I was not certain, it seemed to me that the flashers were working until I cancelled them and the fuse did not blow when they were operating.

I replaced the fuse--this time with a 30 amp unit--and resumed driving, again putting the flashers through their paces, both making turns and letting them auto-cancel as well as cancelling them manually. After a couple of minutes they stopped working--and it seemed to me that there was a loud click (louder than normal) from the trafficator when they cancelled.

Again I replaced the fuse (30 Amp) and started doing the same exercises. I drove for perhaps 20 minutes, went through multiple cycles with the flashers to both sides and now everything worked just as it is supposed to--no blown fuse--despite driving on rough roads, making lots of turns, etc. and using the flashers alot. On returning to the garage I again let the car idle with the flashers on--it just sat there happily blinking away like the cat that ate the canary! So I'm stumped, but I do believe that there may be something going on in the trafficator unit as I clearly remember it having made a louder noise a few times when cancelling, almost like something inside it was catching.

Does anyone have any observations or further suggestions--can anyone think of a scenario where a short or overload would be caused when the trafficator cancels? I am not inclined to take it apart on a recreational basis!

In the meantime we are in for a bout of nice weather here in MD and I will try to do some more driving in the next few days to see if a Healey really has the power to heal itself!

 

[Keoke]

Whew!!!!-----------Great----Keoke-- :laugh:

 

[Randy Forbes]

You've got to love intermittant electrical problems; you just know they'll rear their ugly head at the worst possible time!

Might as well sign yourself up for trafficator therapy :wink:

Good luck!

 

[RAC68]

Michael,

Just a thought. The louder-than-usual click could be the result of fusing contacts being forced apart by the directional return mechanism further amplified when the return springs snap back.

Within the trafficator head are (5) connection studs. Two contacts provide left and right directional activation to the flasher relay with a third delivering power to the lever. Two additional contacts, residing within the same area, provide power and ground to the split rings of the horn button. If one or more of the studs or wire should loosen, it is more than possible that a cross connection is made. Also, since all wires are carried through the stator tube, fraying wire could also result in the same fault condition.

Good luck,
Ray (64BJ8P1)

 

[Michael Oritt]

Keoke--

There is NOTHING great about the fact that I cannot now replicate the situation as even if I were able to fix it I don't know what to fix! But as Randy points out it will probably come back at the worst time such as when I am being followed by a cop who is looking for a reason to pull me over.

As an aside I had such a problem with my boat (now sold) which had a single diesel engine with suction feed fuel lines. There was an intermittent air leak somewhere in the system and at the most inopportune moments such as when entering a harbor from the sea, approaching a bridge or coming to a dock the engine would lose prime and shut down. Since fuel did not leak out but air leaked in it was very difficult to find and I finally had to pressurize the whole system to discover the leak.

Anyway I appreciate all the good suggestions and when (not if) the problem rears its ugly head again "I'll be back".

 

[Keoke]

OH Just consider it has been blessed. Exorcised --Keoke--

 

[mjobrien]

I think I found the fix to your problem.... One of these in arm's reach should keep you out of trouble!

Sorry could not resist!!!!

 

[Michael Oritt]

Mike--

I took the car for a ride today--the fuse blew within 20 minutes, never while the lights were flashing but either when they were cancelling or just not on.

I'm going to the gym to work on my biceps....

 

[Keoke]

Well it look like you had more en one devil in the circuit.
This time the devil is a high resistance short to ground which over the time interval "T"= 20 Min , produces enough heat to blow the fuse. A megger would be very helpful in locating this one.--Fwiw--Keoke

 

[RAC68]

Hi Michael,

If you haven’t resolved your directional problem and still would like some ideas, I have a few questions.

You indicated modifying your directional circuits but never stated how. Your original directionals (flasher and trafficator) receive power from the original fuse that gains power from the ignition switch. Also, your Healey’s directionals incorporated the flasher relay box.

1. How are your circuits fused?
2. How have you incorporated your reflectors as part of the directional circuit (redirected wiring from the flasher relay box or through circuits similar to the BJ8P2)?

Ray (64BJ8P1)