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Still Won't Crank Over

jhorton3

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Today's the first day I've had more than 15 minutes to myself, so I worked on Midgie. I've swapped ignition switches, and starter solenoid, but I still cannot turn the engine over with the key. There's not even a click from the solenoid. I can connect my remote starter switch to either solenoid and crank the engine over. What other component could be creating this gremlin for me?
 
Jeff-Funny thing is it worked for a while with the replacement switch, then stopped. I checked and I'm getting power. Could the voltage regulator close by the solenoid contribute to this? What about the starter motor itself? I would think even if the starter was bad that the solenoid would at least click.
 
Try running a jumper wire directly from the battery to the start terminal on the solenoid.(The small wire.) It's possible that you have a broken wire between the switch and the solenoid, making intermittent contact, or very high resistance in that portion of the circuit.
Jeff
 
It is also possible that the big wire (or an end) from the battery to the solenoid has a break in it. Try running the jumper from the battery to the solenoid and try the key.
Bill
 
Just ring the whole starting system, you know it is the switch, relay, or starter or wireing from one to the other.

Assumes battery is OK.
 
To add to the good advice above, don't forget that the solenoid on LBCs needs a really good ground. Consider at least temporarily putting a ground wire under one of the solenoid mounting screws and anchoring the other end to some good earthing spot on the engine. Speaking of that... does the engine still have a good earth strap to the chassis? make sure it does or you may melt your choke and throttle cables.
 
I took my remote starter switch, attached one lead to the post on the starter solenoid where the positive battery cable connects, and the other lead to the tab where the white/brown wire connects. It'll turn the engine over just fine, so I believe battery is good. Headlights and other lights are bright too when switches are on. Also, this has a new ground strap attached to a bare metal patch on the body/chassis side and the other to one of the transmission/starer bolts.

Doesn't make sense that this worked just fine before I bled my clutch and brake system.
 
Ok then, that starter remote check proved that the solenoid is fine and the wireing from there to the starter and the battery and its wireing.

So, the prob is between the solenoid and the starter switch. If the headlights and such work you know the switch is getting juice.

Check the wire from the switch to the solenoid and make sure you have juice coming into the switch. It is a push button is it not? Is it loose at the starter switch end?? Did it fall off, operator error? If that is not it I would suggest that it is internal to the switch providing you have juice in.
 
Hello Jim,

it's possible that you have your wiring mixed up, the solenoid feed from the ignition switch is white\red, not white\brown. White\brown also sounds wrong are you sure its not brown\white, which probably belongs to the regulator?

Alec
 
Hello Jim,

I did a double check, if it is white\brown that is for the oil pressure switch or from the oil pressure switch to starter relay. I've never seen an oil pressure switch relay for a starter but maybe some US spec cars had them?
Whatever, the white\red is the correct colour for the starter solenoid energising connector.

Alec
 
tosoutherncars said:
jhorton3 said:
I hope that's not the case. This is a new wiring harness.

Aha! Always be doubly suspicious of anything new...


Absolutely, 1000% true. This is fundamental to reliability engineering: the times when something is most likely to fail are (1) when it's old and wearing out, but also (2) when it's new. People always seem to assume that something new will be reliable, but that's not really true. Something new that has some hours of use on it, enough to prove that there are no flaws in manufacturing that might lead to failure, is what's most reliable.

As for the problem at hand, I repeat my usual admonition: buy an inexpensive multimeter, and you can track down problems like this in minutes. Just check the voltage at the important points in the circuit, and you can see exactly where you're losing it.
 
On a '74 USA car the wiring diagram shows white brown coming from a relay the is fed by some other wire(most likely a neutral safety switch)
 
I added another ground strap tonight thinking it might be a ground issue. That didn't help. I'm suspecting this metal covered relay by the starter solenoid. With the test light I checked power to the solid brown wire going in and it tests fine. I checked the white/brown wire for power and it's dead.

I guess curiosity got the better of me and I took the cover off the relay. Very simple inside. Thin wire winding and something that looks very similar to points in a distributor. Cleaned the contacts, but still no go.

Looking at Moss & VB I don't see a part # listed for this. I do see something similar in the MGB part #542-235. I'm wondering if I can just bridge the brown wire that goes into this relay with the white/brown and see if that makes a difference.
 
Did you have the starter switch engaged when you checked the white brown wire?
 
Yep. I turned the switch to run and start with no indication of power on white/brown.
 
As others have already said- the trigger wire to the solenoid should be white/red. If you have a white/red wire in the area you may want to see if it is activated by the starter switch.
Bill
 
Bill-No white/red wire in the engine bay. It's white/brown for this car. The ignition switch has a white/red wire and attaches to a white/red in the wiring harness, but that connects to the black box under the dash in a multi port connection. The black box is/was for the seatbelt system.
 
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