• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.

    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Spitfire Starter problem, 78 Spitfire

Joe_Pinehill

Jedi Hopeful
Offline
I went for gasoline, and when I tried restarting, the starter did not budge, I was able to have the attendent push me and poped in gear and it started right off.

When I got home, I check connections from the key switch, look ok.

Checked solenoid, (it looks original) when i probed both of the high current posts, I got 12 volts without the key in, Is this is a sign of the solenoid pulled in, and chared surface is enough to pass voltage but at low current?

When I used a jumper cable and touched the negative high current solenoid post to the positive battery post, the starter turned.

Ive disconnected the battery and plan on picking up a solenoid. The Moss catalog has an after market for 13 and lucas for 39, is it worth the extra money for a Lucas?
 
My 75 has the original solonoid and it doesn't have the push button. I think it was on ealier models only.
I can't think of a good reason to have 12 volts on both posts of the solonoid when it it not engaged.
Another place to look for trouble is the start interlock relay.
This relay is part of the Smiths Module circuit. Most cars have the Smiths Module disconnected but the start interlock relay still has to work.
I had the same thing happen as you Joe. It turned out the solonoid was fine but I had to clean the contacts in the start interlock relay.
When you turned the kay to start, did you get any sound at all? If you got a click then the start interlock relay was pulling in if you got no noise at all then I wouldn't change the solonoid just yet.
You can also substitute some american car solonoids if you want to just go down to the local auto parts store and not wait for shipping.
 
If its a round relay, near the solenoid, my starter relay was overriden by the PO, he left it in place, Im away this weekend, just ordered the part from MOSS and hopefully can play with it on Monday
 
The starter relay is rectangular and mounted behind the coil. If the new solonoid doesn't solve the problem let me know. Have a good weekend.
 
Joe, before you spend money on any solenoid, remove, thoroughly clean and reinstall both ends of each battery cable and the connections to the solenoid and the starter (and any earthing strap present from engine to chassis). It might be as simple as dirty connections causing the problem you have, and it's worth the 15 minutes' work to find out!
 
I did sand paper all the leads and ground. No change. I have a solenoid with a button in the middle, is this supposed to move when you press it? Mine is solid in place.
 
Joe_Pinehill said:
when i probed both of the high current posts, I got 12 volts without the key in,
Just curious, was the starter still connected at that point?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I have a solenoid with a button in the middle, is this supposed to move when you press it? Mine is solid in place.[/QUOTE]
I'm not certain, but I believe Lucas made them in both flavors. On some units (earlier, perhaps), the "button" is a rubber cover that lets you press against the armature inside and thus activate the starter. On other units (later I think), the molded plastic part sticks out into the same size and shape, but is solid and does not move. The two types are otherwise nearly identical.

But the diagram I have for a 78 US-spec Spit shows a "4 terminal" solenoid, and I've never seen one of those with the rubber button. (Not that I've looked much
grin.gif
)
 
Joe_Pinehill said:
yes, the starter was still connected
In that case, it seems to me that you must have another problem besides the solenoid (if it is bad at all). 12v on the load side post should make the starter motor run.

If you can find 12v on that post again, try chasing it towards the starter. If it goes away before reaching the starter post, you've got a bad connection somewhere. If the starter post has 12v and the starter is not running, then the starter motor is bad or not grounded.

They do sometimes go intermittant : there is a Stag starter laying on my garage floor that would sometimes refuse to run and then later seem to work just fine. It turned out to have some bad segments on the commutator, making it weak only when it happened to stop with a bad spot under one of the brushes. Apparently there was exactly one position where bad spots would line up with two brushes, disabling it completely.
 
I'm away for the weekend, and cant troubeshoot. I'm going to start with the solenoid, for $15 that takes its out of the equation. It does look very very old, if its not the original. After 32 years it deserves a new one.

I have had solenoids pull in, but be chared enough on the contacts, to have very high resistance, let some low current pass, but not enough to turn a starter.
 
Don't forget to check the ground cable. Mine was not making a good connection to the bell housing. I ended up making a cable that goes from the battery straight to the starter mount bolt.
 
Update, New solenoid did not fix it, the ignition swith is shorting somewhere . I dont want to spend the money for a new switch now, so i ran new wires to the low current side of the solenoid, and fused it, and have a push button swith to start. works fine.
 
Back
Top