T-Series & Prewar Forum

With key on but not running !
Got all dash lights
Got fender lights
Got Fog Lights
BUT No HEADLIGHTS

Test lite shows
Both 2 Fuses have Power

But on V/R ( that's 5 poles)
Only the 1st 2 show power
0 on the other 3

Any Help ?

did they ever work? if so, when and what has transpired since that time with the electrical system?

Have a 51 TD
V/R has only 5 screws
Headlights and everything was good
Took it around a big block and I smelled something funny
Got home and in garage ( No Fire /Thank God )
Checked things and wires going into the 2 holder fuses looked kinda burnt and smoking a little
Took wires loose / unhooked battery
The L horn smelled bad took cap off and it was kinda fried
Then I took the H horn off and it was worse
So than I took the Horn button switch out and it was fried too !
Got horns coming
Got a new Horn Switch like the 1 Moss sells with the 4 wires
Today I got switch in (horn) and temp wired together
Key off
I had power to the 1st 2 screws on V/R and only 1 fuse on ( holder of 2 )
Key On
Red light on, fuel pump could hear pumping
All dash lites on (with lever turned on in switch)
Fender lies on
Turn fog lites on
BUT NO Headlights
So I unhooked battery, disconnected wires on new switch AND Still No Headlights
So now asking for help
Did take cover off V/R and top wire kinda that goes into it at top was dark ( burnt ? )
Oh, the L horn light wire that has 2 holes it was hot,the other pigtail wire wasn't !
On the H horn light wire with 2 holes was no power , but the Pigtail one was hot !
That's all I can remember
Sorry about book 82/and Deaf !

First thing you should know is the lights are not fused. Another important thing to note is that the combo horn/ light switch should be checked to make sure the wiring is correct. I bought a new one for my TD a number of years ago and the wiring was not correct. First time I tried the horn after the installation I released some valuable Lucas smoke from the wiring. I found out later that I wasn't the only one that got an incorrectly wired switch. If the windings are not fried on your horns ten they may be salvagable so don't throw them out just yet.


Since I can't see your dash I assume you have the headlight/park lights on the key switch. I would then assume that the hi low beam switch is built into the horn switch. The key does not need to be on to operate either the horns or the lights. The horns do go through the fuse which is hot all of the time. The other fuse runs hot only when the key is on.

To trouble shoot the issues,,,,, leave the fuses out for now. start by checking the wiring on the back side of the headlight ignition switch. Most likely you will have to remove the center dash panel to see whats going on. Use the wiring diagram and check all of the wires are in place and are going to and from the switch to the correct locations. Something may be loose . Check the terminals and the color of the wires coming out of your new horn switch. On the one I had all of the wires (by color) were off one pole counter clockwise as seen in this photo. The end result was when I pushed the horn button it created a dead short and things got ugly real quick. Notice the wire missing the bullet connector. It melted the solder and the bullet end came right off. I moved all of the wires one terminal in a clockwise direction so the blue wire is in the position of where the blue white wire is in this photo. Just make sure your new switch wired correctly. The power for the head lights comes from the key switch through that solid blue wire and is then directed with the switch handle to either the high or low beams which are the blue/white wire and the blue/red wire. The brown wire goes to the horns and when pushed provides a ground for the horns.

Once you have the headlights figured out, move onto the horns. The fuse should have blown before damaging the wiring. That is what they are there for. The horn fuse should have been a 50 amp Lucas type fuse. Not to be confused with a 50 amp American type fuse from your local parts house. The other fuse which runs through the key switch should be a 35 amp Lucas type fuse. If somebody put American type fuses in there then the wiring will burn up before the fuse blows as the American type fuses will take about twice as much amperage to blow verses the Lucas fuses.

Good luck.

The picture looks like mine ! I need to take it out to make sure was really hard to get the nuts on !
I've read where Moss had wires wrong and caused fires
So take fuses out to play safe ? Will I still have power to turn on Red light and lights ?
Think.so got my work cut out !
THANKS !!!

Thanks again ,I understand the 2 fuses now !
What about the 5 pole or screw voltage Regulator
I only have the 2 shows that they are hot !
Should the other 3 be hot too ?
Maybe I'll take Horn switch out
Can I hook the wires to it out of the hole in dash or does that ground the switch ?
They ( people) I bought it from had a switch like this , not sure if color code is the same tho
It had the 4 wires plugged into switch
They had 3 wires connected to 3 and than I think the 1 wire from the key switch was connected to 1 of the wires ( not sure if I have it connected right )
Seems like it (a wire from horn switch should go to ignition switch for power )
Thanks for help Pete !

Pictures of what you have would be a big help

When you were removing wires from the grub screws were any of the screws loose. This will cause increased resistance and cause the wires to fry. You’ll need to go through the horn and headlight wiring thoroughly and replace / insulate all fired wiring. Pay attention to where the wires go through the front wings there should be grommets on the wings for the loom to pass through the wires could potentially have been cut if the grommets were missing or rotted. This is also true for the firewall grommets. If you have an original harness that is old and the sheathing deteriorated and wiring is brittle it’s high time to replace the harness in it’s entirely. There have been too many horror stories on owners loosing their cars to electrical fires. When you experienced the wiring failures where you using the headlights at that time or operating the horn? It was this a spontaneous event. Had you changed or manipulated the harness in any way prior to the event? Check every grub screw connection on the harness for loose connections. Check the wiring as it travels through the headlight mounting brackets and into the buckets check the connections within the buckets. This has become a regular maintenance item for me. I check my harness connections annually after having an event such as yours even with a new harness in place.

If you still have the underdash panel in place remove it so you have immediate access to the underdash wiring at all times. I highly recommend that you also purchase a halon or FireStick type of extinguisher and have it handy for the future.

---

Bill Chasser
TD-4834
TD-5779
TD/c-8151
TD/c-16920
TD-19408
TD-24060

TF-8200



Edited 1 time(s). Last edit at 2024-04-16 03:31 AM by TD4834.

vintage body styles from the mid-thirties and older with separate headlight buckets are susceptible, by design but not intent, to grounding problems. sometimes, running a temporary ground wire directly from the bucket to the ground on the battery can help in diagnosing problems.

I don’t mean to high jack this thread but I’ve got a similar situation. I also have a 51 and I’ve got 12 volts at the headlight bucket. Only one of the power wires has juice depending on which way the dip switch is set and the ground seems to be working per the voltage meter. I can get the sealed beam to light if wired directly to the battery but no joy when hooked to the wires at the bucket.

The sealed beam is an off the shelf from auto zone. Would it require me to have a relay for it to work?

Thanks
Have a Fire Extinguisher , need to check it and make sure it works !

Thanks
Think I got my work cut out!
Hopefully I can get it fixed before getting really nice out
Deaf Pete

Yes, wife let me sleep in, got farm dogs to walk and got to see Doc at 11, but I'll try getting pictures !
1 big thing , got new 4 wire horn button switch from Abingdon Spares
The end of 4 wires had big male pig tails and couldn't find a female end to fit over them so I had to make shift the piecesetc
Going to start all over and go to Electrical store today andsee if they sell them
Thanks Deaf Pete

You are very unlikely to find the bullet connector ends locally. They can be purchased from nearly all of the British car part vendors. I have a number of old harness's in a big tote that I remove the soldered connectors from when needed. Some are crimped and not useful to me for that purpose. Same goes for the connectors.

Thanks
I just ordered the parts from Moss but they were less than 10 so I had to order more to meet their order $
So if you need any let me know
I even went to the Big Electrical Co. here in Lafayette , they said it would take 2 weeks or longer and take a long time to just get cost for each plus ship etc.Anyway old and deaf but THANKS
If you need the bigger female ends let me know
Thanks Again Pete
I see you are help a lot of people like me , even if we don't say thanks we mean Thanks
Guy in Calif, like you restoring his TD , I don't see how he gets anything done with me bugging him (Bruce Cunhan)
Thanks Deaf Pete