TRExp

TR6 Tech Forum

Red ignition light comes on when either the parking or headlights are on.

Moss Motors
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor

nync Glenn Meteer
Charlotte, North Carolina, USA   USA
I have all the lights working now, but the red ignition light comes on when the parking or headlights are on. Also, the blue highbeam light is on whether in high beam or low beam. The green oil light and red ignition lights come on when starting, but go out when it fires up. All the instument lights work. It has a new battery.
Any ideas out there what could be causing this light to come on when the lights are on?

Could this be the alternator starting to fail?



Edited 1 time(s). Last edit at 2017-09-12 08:15 PM by nync.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Krom Avatar
Krom Paul K
San Rafael, CA, USA   USA
Glenn- a couple of thoughts/questions: does the ignition light go out when the headlamps are on and you increase revs? Does the intensity of the read light vary with engine speed? You didn't mention the year of your car. Do you have an ammeter? The fact that your high beam indicator is whether in high or low beam mode indicates you have some wires misconnected. Someone in this forum with more knowledge than I (who doesn't!) can guide you about testing the output from your alternator. You didn't by any chance recently remove a battery cable while the engine was running? PK

nync Glenn Meteer
Charlotte, North Carolina, USA   USA
Paul, thanks for your response. It is an original, low CC# 1969 TR6. The red light comes on when the lights are on (either parking or headlights) and the intensity of the light does not change with the RPM's. Last night the light was on at idle and all the way to 4000 RPM. The ammeter is the original Smiths 30 - 0-30 gauge. It has an new battery but the battery cables were never removed while the ignition was on. The alternator is an older rebuilt Lucas, unknown output.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
tapkaJohnD Avatar
tapkaJohnD John Davies
Lancaster, Lancashire, UK   GBR
Glen,
the red light shows that the voltage at the alternator is greater than that at the battery, in other words if the battery is being charged or not.
It's red when you turn the ignition on, as the battrey is supplying all the cars needs, mainly ignition, but goes out when the engine starts as it takes over supplying all the car's electrical needs.

So if it comes back on when the lights are turned on, then that extra load on the electrical system is tipping the balance towards supply from the battery - the alternator is inadequate.

But it might not be alternator failure. A loaded alt. needs quite a torque to turn. Have you checked the fan belt, that turns the water pump (and fan) and the alt?
On the longest run of the belt (alt to crank pulley) you should not be able to deflect it more than 1" (1/2" each way) If more tighten it.
Also inspect the belt sides - is it polished and worn? A new belt might help.

If these all satisfactory, theh there are simple testing methods in the TR6 WSM to check the function of the capacity of, and control unit in the alt.

Good luck!
John



Edited 1 time(s). Last edit at 2017-09-13 03:57 PM by tapkaJohnD.

nync Glenn Meteer
Charlotte, North Carolina, USA   USA
Thanks John. I tightened the belt, it was a little loose. As I check the bullet connectors on the headlight switch, one double connector crumbled in my hand, little metal pieces fell out. So I ordered some new connectors. I guess a 48 year old car has aging parts in many places!

Krom Avatar
Krom Paul K
San Rafael, CA, USA   USA
Glenn- ah yes, the wonders of the TR electrical system! Sounds like a series of checks may be in order. If your wiring harness is original, you may want to do some extensive checking of connections with particular attention to the system grounds. Buying new connectors (the black sockets into which the bullet connectors fit) and using emery cloth or other abrasive to clean up the bullets is advised. If you don't have a capable ohm meter, invest in one to check continuity. This is a constant issue with an old set of circuits. A pack of new connectors and a soldering iron is pretty much a given as some of the connections will be shot. Glad you are making some progress. Depending on your budget and time, you may want to investigate a new harness...PK

ng19delta Avatar
ng19delta Scott Roberts
Merchantville, NJ, USA   USA
1974 Triumph TR6 "Not Sure At The Moment..."
Sure you don't have the gauge illumination lamps in the wrong places? Just thinking out loud...

Scott

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
nync Glenn Meteer
Charlotte, North Carolina, USA   USA
Scott, thanks for the idea. Tonight I took the car out and carefully observed the instruments. This is after I replaced some connectors and followed the wiring diagrams. Result: ( I am a little sheepish to admit) one of the speedo lights was in the high beam hole, switched them aound and it now works correctly. The issue with the ignition light coming on is actually light from the tach bleeding through to the oil light and the ignition jewels, so they appear to be on whenever the lights are on! I wonder if when the tach was rebuilt they didn't replace the light shields (if there is such a thing)? So I will just live with it. I pulled the ignition light out and it was still unlit, I put it back, no change except when starting (it got brighter) Thanks for all the suggestions! I appreciate all y'alls responding to my posts!



Edited 1 time(s). Last edit at 2017-09-17 08:21 PM by nync.

ng19delta Avatar
ng19delta Scott Roberts
Merchantville, NJ, USA   USA
1974 Triumph TR6 "Not Sure At The Moment..."
In reply to # 1485909 by nync Scott, thanks for the idea. Tonight I took the car out and carefully observed the instruments. This is after I replaced some connectors and followed the wiring diagrams. Result: ( I am a little sheepish to admit) one of the speedo lights was in the high beam hole, switched them aound and it now works correctly. The issue with the ignition light coming on is actually light from the tach bleeding through to the oil light and the ignition jewels, so they appear to be on whenever the lights are on! I wonder if when the tach was rebuilt they didn't replace the light shields (if there is such a thing)? So I will just live with it. I pulled the ignition light out and it was still unlit, I put it back, no change except when starting (it got brighter) Thanks for all the suggestions! I appreciate all y'alls responding to my posts!

winking smiley It happens... Lots of same size holes back there, and hard to see which wire is which...

Scott

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
. Hide banner ads & support this website by becoming a > Gold Supporting Member <

To add your reply, or post your own questions

Members Sign In   or   Create an Account

Registration is FREE and takes less than a minute!


Having trouble posting or changing forum settings?
Read the Forum Help (FAQ) or contact the webmaster