You are here:

Triumph Repair/Spitfire solenoid/ignition switch

Advertisement


Question
Solenoid.jpg
Solenoid.jpg  
QUESTION: I have a 74 Mk IV Spitfire that I am trying to get back on the road after a major rebuild. The car has been off the road for years before we bought it and completed the rebuild. It recently passed it's MoT.

Since then I have had problems starting. I have fitted a new solenoid and just today a new fuel pump. Today I can start the car but the starter continues to turn. In fact I now find that it is turning when I select the "on" position on the key (position 2) never mind when I select the start position (position 3). I am resigned to there being lots of problems as it starts to run again, but this sequence is getting me down.

My first guess is that the ignition switch is to be replaced but it could be the solenoid. I'm not entirely convinced of the correctness of the solenoid wiring contacts. They are currently as in the attached picture:

   A - Solenoid +ve to battery -big black
   B - Solenoid -ve to starter - big black
   C -Solenoid 2 to coil +ve - Brown
   D - coil -ve to distributor Cream/brown stripe
   E - solenoid 1 to wiring loom - Blue/white
   F - Solenoid 2 - to wiring loom - green/white
   G - resistor to coil+ve - black
   X - other wires that go into the loom - brown

Note that they are not the original wire colours. Can you see enough to decide if they are correct? Any ideas gratefully received.

If it is the ignition switch, how big a job is it to replace?

ANSWER: Hi Richard,

I can't make out much from your photo because many of the wires are home made. I can give you the wiring of a Triumph and you can then use a 12v test light to check which of your home made wires do what. Then you will be able to wire it so it works.

To start with your starter solenoid should have 4 posts. Two large and two small. One of the large should has several small spade connectors on it. The large post with the several small spade connectors should have the (+) battery cable on it and the small spade connectors should be 4 of them. 2 plain brown wires from your alternator, One plain brown wire to your fuse panel. And one plain brown wire as power TO your ignition switch.

There should be 2 small terminals on the solenoid (they were usually different size so you couldn't get the wires mixed up but some replacement solenoids had both small termainals the same size so we had to replace the wire end to be able to connect it. That smaller spade terminal had a White w/Yellow traceer wire on it that went to the coil and resistor wire for the coil. (This terminal on the solenoid supplied 12v power to the coil ONLY when the solenoid was activated as a bypass to supply direct power to the coil whan starting.)

The other small terminal on the solenoid was the "Trigger" wire from the ignition switch "Start" position. (only hot in the "Start" position) this wire was White w/Red tracer wire.

It sounds like who ever rewired your car got the wires mixed up. That could have happened at the back of the start/ignition switch also so check that too.

Let me know,

Howard

---------- FOLLOW-UP ----------

Solenoid 1
Solenoid 1  

Solenoid 2
Solenoid 2  
QUESTION: Howard

First - thanks for the reply and the info. I have taken a couple of days before I could get back and do some more - so apologies for the delay in re-posting and thanking you.

However, I'm no further forward. I have done some checks as per your suggestions and:
- The large connectors on the solenoid are connected correctly as far as I can see. One large wire to the starter on one large terminal. From the other large terminal there is a large wire coming in from the battery and 4 smaller brown wires - as per the various wiring diagrams and comments. I have assumed that they are all correctly routed as they haven't changed since it last worked all OK.
- one small terminal, on the drivers side, the right side looking forward (it is RHD car) - which is the larger of the 2 small terminals has 2 wires coming off it. One (brown) short wire goes to the +ve side of the coil. That then goes on via a white/black stripe wire to the distributor - again as per wiring diagrams. the other wire is the white and green wire that goes into the wiring loom. When this wire is touched to the battery input wire there is no response. So I presume it is the one which should be white with a yellow trace. These 2 wires connect to the solenoid via a "double" connector - i.e. one wire clips to the solenoid terminal and the other (the short brown one) connects to that. Note that this short brown cable is too short to reach to the other side of the solenoid and so (I guess must belong here).
- the other small terminal (the smaller of the 2), on the left side of the car looking forward, has the white and green wire connected to it. This does energize the solenoid when connected directly to the battery cable. So I presume it is the one that should be white with a red trace.

So - as far as I can see, they are correctly connected. I have attached 2 more pictures to (hopefully) make it clearer.

I did try to reverse the white/green and white/blue wires and when I did nothing happened when I turned the key.

When I move the key to position 1 (accessories), I get nothing. When I move it to position 2 (ignition), the starter turns. If I move it to 3 the engine fires (but I turn it back quickly).

I would be truly thankful for any ideas. It all worked fine before the new solenoid!

Don't you just love old cars as they are so simple to work on!!!

Answer
Richard, your photos are of no use because the wiring is home made and not Triumph.

All of the brown wires with the large eyelet ends do go on with the battery. So you should be ok there.

Remove the small wires off of the small terminals on the solenoid.
Now you need to know what wire does what and forget the color because it is all wrong anyway.
Now take a jumper wire and connect it to the battery terminal and take the other end of the wire and just touch it to one of the small terminals on the solenoid. And touch it to the other small terminal and only one of them will activate the starter motor. Label that pin the "Start" connection. Label the other one that did nothing "Coil" Power.

Now take either a 12v test light or a volt meter and connect the ground lead of you test light or Volt meter to a good ground and have someone turn the key to the "Start" position and test which of the loose wires is hot when the key is in the "Start" position ONLY (not the little short wire going to the coil in your photo. When you have found the wire that is HOT when ONLY in the "Start" position plug it onto the solenoid that you labeled as the "Start" pin. No other wire connects to that terminal. Now the other small terminal on the solenoid should get ONLY one wire and that goes to the Power side of the coil.

That will make it operate as the Triumph factory intended.

Let me know.

Howard

Triumph Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


Howard M. Fitzcharles III

Expertise

Triumph TR-4 up & Spitfire, and Engine theory

Experience

Dealership line mechanic on MG, Triumph, Jaguar for 15 years, Instructor in commercial mechanics school 2 yr. Product information manager for piston and valve manufacture, Instructor & hotline answer man for import car parts importer 15 yrs.

Organizations
Associate member SAE EAA member

Publications
Import Car magazine

Education/Credentials
ASE Master Auto with L-1 certification up to 2000

©2016 About.com. All rights reserved.