Spitfire Supositions Wanted - '72 Spitfire Charging/Not-Charging Issue

[dklawson]

Yesterday I got a call from #1 son that his '72 Spitfire will not start. He said that the dash warning lights would come on and he could hear the electric fuel pump running but when he turns the key to the start position they all go out and the pump goes silent. Since he didn't have a volt meter I told him to check to see if the headlights came on, which they don't. I then suggested he turn the key to the run position so the dash lights and fuel pump were on, then turn on the lights to see what happens. The lights and pump shut off.

That tells me the battery is totally flat. I suggested he have a friend jump start the car. When they tried this he said the car still wouldn't turn over and that now the ignition warning light didn't even come on. I asked if they hooked the jumper cables up "backwards" but he assures me they didn't. We will see.

I am headed to the university today with a trunk full of tools, parts, and the battery from the GT6. I suspect it is the generic aftermarket alternator that is on the car as the battery was replaced in the spring. We had to install the aftermarket alternator (which was a spare supplied by the PO when we bought the car) when the original Lucas 5-wire alternator died through some failed diodes (badly assembled rectifier plate... not apparently a true electric issue). I am taking a Ford Fiesta alternator with me. I bought the Fiesta alternator to have as a spare for the Mini and the Spitfire but I have never tested it. Hopefully it was rebuilt properly, works, and can use the same belt.

We had the aftermarket alternator installed before and I removed it when some intermittent charging problems surfaced. Hopefully that is all that has happend again. I plan to do a few basic tests, then install the GT6 battery, hopefully start the car, and make some voltage measurements. The Fiesta alternator may happen in the parking lot if necessary should the voltage tests dictate it.

I know we'll get this sorted quickly but I am looking for other things to check when I get to the car today. It's raining a bit outside and I am getting older and don't enjoy working in the cool damp weather. If you have other ideas for things to check I welcome your suggestions.

 

[TomMull]

First thing I'd check is the battery terminals. May not be an alternator issue. Tom

 

[TR3driver]

Assuming they had the jumper cables hooked up at all, then it sounds more like a bad connection somewhere between the battery and the car. Maybe a loose bolt at the ground strap, or something like that. Even with the battery totally dead, they should have been able to get at least dash lights from just the jumper cables.

If I was anxious to get out of the rain, I'd start by repeating the experiment with the jumper cables. If you still get no lights with 12v supplied to the battery clamps; then changing the battery or even the alternator is not going to help and is just time wasted that you could have spent finding and fixing the problem.

BTW, HF has their cheapest DMM on sale right now for $3. I carry one in every car, even the "modern" car. Put it in a baggie and drop it into the middle of the spare tire.

 

[dklawson]

I thought I had put one of the HF multimeters in the boot but my son couldn't find it. I suspect he wasn't sure where to look or what to look for.

I will start with checking all the connections and cables. I brought several used, partial cables with me to temporarily connect as needed.

With all my British cars I have a ground cable from the battery to the body and from that same body point/bolt I run a second cable directly to a starter motor bolt. That's why I was concerned when they said after trying the jumper cables they had no charge warning lamp.

My plan is to spend no more than an hour looking at the car in the dorm parking lot. If I haven't found it by then I will call AAA. I haven't had to call for a tow in a long time. Today might be the day.

 

[dklawson]

Home, surprised, and hopefully fixed.

When I got to the dorm I took my voltmeter and checked the battery and found it had 12.5V on it. Knowing that the headlights didn't work yesterday I wiggled all the brown wires on the solenoid, then the ground wire from the battery to the chassis. This car has a marine battery terminal on the ground post. Those "unscrew" with either a wing-nut or knob so you can disconnect the battery quickly. When I checked the battery ground wire it was loose so I tightened its knob and asked my son to turn on the headlights. They came on. Then I told him to start the engine and it fired right up. He was very embarrassed but I told him not to be and that I was glad it was something so minor. While the engine was running I checked across the battery terminals and found the alternator brought the voltage up to an even 14V. Also good.


I followed my son on the backroads for the 25 mile drive home just to make sure it wasn't something else. No hitches no matter how many stoplights we hit. The car ran fine. Like I said, he is embarrassed but I was gratified to know he had pulled out the wiring diagram and spent time last night studying it and trying to figure out where he had lost power. There is hope for the next generation.

Thanks for the suggestions guys.




This weekend we'll wire brush the terminals and fit a star washer under the knob to keep it from working loose.

 

[TR3driver]

This car has a marine battery terminal on the ground post. Those "unscrew" with either a wing-nut or knob so you can disconnect the battery quickly. When I checked the battery ground wire it was loose

Did I nail that or what!


Glad you got it fixed, Doug. Also very cool that your kid not only drives a Triumph, but is willing to learn from it. There is indeed hope!