Hey all!

My 1974 124 Spider (1800) was running totally fine, I was burping the coolant, and then suddenly the whole car shut off. When I tried to start it back up the car just made one tick noise and nothing else. I checked the battery which was fine. I think it might be the connection to the starter motor. Maybe some coolant got on some wires? Any suggestions? Should I try replacing each wire individually to the starter motor? Or just put in a whole new starter motor. Or is it something totally different. My knowledge and expertise are very limited...
Thanks,
Levi (Canada, BC)

I am the least of mechanical people. I will try to get them giving better suggestions. Antifreeze should not long term stop the starting issue. Get a volt meter or current tester (light) to verify that the starter has electricity. If it does you should not need to replace wires. There also should be several tests to check starter.
starter has nothing to do with a car running and then suddenly shut off.
Suspect multiple issues. in modern cars it sounds like crank shaft sensor, and cant tell where it is. I feel that something is telling starter not to move, unless the car ground suddenly failed. Loose battery connection, or as in the 1980 fiat the short ground wire that attaches to the battery box. Mine has had poor contact in the past. Ground failure does bring strange and varied issues. I had replaced a starter before I verified the ground issue.
hope this gives some area to start. good luck

I wouldn't recommend changing any wiring or fitting a new starter motor until you've determined what has actually gone wrong.

I'm curious as to why you were burping the cooling system?

Even if some coolant (I'm assuming by this you mean water and anti-freeze mix?) did splash down onto the starter motor (iirc, the starter motor is below the inlet manifold on the same side as the coolant expansion bottle) I can't see how it would cause the engine to stop and not re-start. The main power terminal on the starter solenoid (the big power switch on top of the starter motor) is covered with a large rubber boot, so is well protected.

If a lot of coolant got splashed on the ignition distributor, it might stop the engine but wouldn't prevent the starter motor working.

Is the timing belt still intact? If this snapped or jumped several teeth, it would cause the engine to stop and, depending on how much internal damage has been caused, might prevent the starter motor from turning over the engine.

Is it possible that some coolant splashed into the carb intake if the air-cleaner was removed at the time? This might cause the engine to cut-out. It would then be a little difficult to re-start it, depending on how much coolant got sucked in. If a huge amount got in, it could stop the engine dead and it wouldn't subsequently turn over either (hydraulic lock in one or more cylinders, liquid is incompressible).

Is it possible that the engine has seized? To check for this, if the starter motor won't turn over the engine, you can either put a socket and bar or a wrench on the crankshaft pulley nut (iirc the size is 38mm, the same size as 1 1/2 inch) and see if the engine can be turned (be sure to have the ignition off while doing this).
Or if the car is a manual transmission (stick-shift) you could put it in 4th or 5th gear and try pushing the car to see if the engine turns over - do this with the ignition turned off.

You say the starter motor only made a click when you tried to re-start the engine after it cut-out, to do a quick check on the starter motor, try briefly operating it with the headlights turned on. If the lights dim or go out, there is power getting to the starter motor, so it and it's associated wiring and ignition switch are probably ok.

Try the above and report back with your findings.

Al.

I was burping the cooling system as my fan hadn't been turning on. I read up on the common issue of air pockets building up and not allowing proper circulation which affected the fan turning on and off. When I was burping the system from the top of the radiator A LOT of air pockets (bubbles) were coming up so I thought that was good. The radiator was super warm on both sides though. My additional thought was to replace the thermostat which I've done as well but I can't test out the newly burped coolant and thermostat to see if the fan will now run because the car won't start.

Yeah you have a really good point, I don't think the issue is starter motor based, not sure why my initial thought process brought me there but I'll still look into what you said!

Also I don't think it would've been the carbs, they're on the other side of the engine and the coolant wasn't burping that aggressively.

I am really interested in the seized engine theory! I'll pop it in 5th gear (I assume 4th or 5th work equally well) and I'll see if I can push the car and turn the engine. If in fact I can't and the engine does appear to be seized, what should my next course of action be?

An additional side note I have is that the car doesn't have an alternator belt on. When the car died I attached my brother's new and fully charged battery with still the same result when I tried to start it.

Thanks so much and sorry for the long reply and dealing with my noob level knowledge.

Levi

Hi Levi,

You mention not having an alternator belt fitted.
This wouldn't affect the operation of the starter motor or prevent the engine from starting.
However, I hope you weren't running the engine for long without it fitted and certainly not while warming up the engine and burping the cooling system.
The alternator belt also drives the water pump. No belt = no water circulation = very bad. cry

Best to now check if the engine can be turned over by putting the car in 4th or 5th gear (both work equally well) and pushing it (with the ignition off).

Let us know how this ^^ works out and we'll take it from there.

Regards,

Al.

Hey,

Sorry it took me so long to get back to you all, working and started spring courses! So after a friend came by and we spend a while looking over the whole car, long story short the issue is with the wiring. The starter motor works fine, there is an alternator belt, I was mistaking the air pump for the alternator :/ (which I found doesn't need a belt, emission regulation part).

Essentially there are a few bad wires specifically ones that are going to the ignition coil as it is getting no power. To make matters worse the previous owner had spray painted everything black so looking at the different wire colours isn't working.

If anyone has a wiring diagram or knows where I could buy a repair manual for a 1974 Fiat 124 Spider, that would be greatly appreciated!

Once that wiring issue is dealt with, all I need to do is replace the gasket for the thermostat (also need to figure out where to buy one of those), and the car should be good to drive around! Maybe buy and install some seat belts too....

Thanks,

Levi

all I can say is type in fiat 124 shop manual. Mine that I recommend is from 1975 and newer. not 1974. There are several to chose from on ebay. I like paper over computer, but there are those as well and cheaper. $10 compared to $70 ish.

So even though I have a 1974 124 you think I should get the 1975 - 1982 model? Does this one (link below) look about right for me? Would it have wiring diagrams? Thanks!

https://www.emanualonline.com/Cars/...MI77XyjNmv6QIVbx-tBh0CZwZrEAQYASABEgLnePD_BwE

levidvorak said:

Hey,

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Essentially there are a few bad wires specifically ones that are going to the ignition coil as it is getting no power. To make matters worse the previous owner had spray painted everything black so looking at the different wire colours isn't working.

If anyone has a wiring diagram or knows where I could buy a repair manual for a 1974 Fiat 124 Spider, that would be greatly appreciated!

Once that wiring issue is dealt with, all I need to do is replace the gasket for the thermostat (also need to figure out where to buy one of those), and the car should be good to drive around! Maybe buy and install some seat belts too....

Thanks,

Levi

Click to expand...

Hi Levi,

Good to hear that you hadn't been running the engine without the water pump working, I was fearing that your engine might have seized.

Rubbing the wires with Lacquer Thinners might remove the black paint on the wires or else just scrape lightly with the edge of a knife/blade.

I'd suggest getting a manual that includes your specific year model - sometimes there are changes on later manuals especially to wiring diagrams if any additional item of electrical equipment is fitted.

Don't get into a panic about wiring colours, they stay the same on all older Fiats (other Italian cars also) for a specific purpose/destination e.g. dip beam headlight always use grey wire for the supply, main beams use green. A tracer colour is use to indicate which side, or sometimes after a switch e.g. left side might include a black tracer stripe or a black band at intervals to indicate this wire is for the left side unit. After a while, you get familiar enough with the colours not to need a wiring diagram for simple fault-tracing.

www.midwest-bayless.com are a good source of parts for older Fiats.

www.haynes.com/en-us/fiat/124/1968-1978 =a paper shop manual for the 124 Coupe and Spider 1968- 1978 models and includes good wiring diagrams

There are 2 types of thermostat used on the 124 Spider - one fits into 3 hoses adjacent to the water pump/radiator, so no gaskets are used.
As you mention gasket, I'm assuming your's is the other type that fits in the cylinder head under the top water outlet - this uses a rubber O-ring (not a gasket) to seal it, but the top water outlet does also have a gasket between its 2 halves. To save time/money, the O-ring can be re-used if undamaged (it rarely leaks) and the gasket can be re-used if undamaged, maybe give it a light smear of non-setting gasket sealant (e.g. Hylomar or one of the Permatex products). If the gasket is damaged, you could make one from gasket material or even the cardboard from a cereal box, just give it a smear of sealant (they rarely leak).

Al.

So I found a wiring diagram, met with a guy who knows a lot about these cars and deduced that the issue is the ignition switch!! So looks like most likely I'll have to buy a new ignition switch and replace that, hoping it's not too difficult/complicated of a job! Also hoping that is the final and only real wiring issue I've been dealing with.

Also yes my Fiat has the internal thermostat that fits in the cylinder head. The rubber o-ring does have a decent amount of wear on it so I feel like I might as well replace it. Hoping I could order both a new ignition switch and rubber ring from Autoricambi.com

Another thing was that the thermostat I put which I got from Lordco opens at 160 degrees but the original one opened at 190 I believe. Do you think that is a big issue? Should I try to find a 124 specific thermostat? I know autoricambi sells them.

I also was looking at my air pump (that emissions thing) and it is entirely broken and also without a belt. I am planning on taking it out and then replacing each of the 4 small hoses that go into the engine with bolts to block them off. The only problem is sizing, I'm not sure what size bolts would fit best. I could perform a trial and error type procedure but if you already know what size bolts would fit there, that'd be a huge bonus and help! Photos of one of the four small hoses will be attached. I tried pointing right at one of them so you can see. You can also see my new internal thermostat in place.

Thanks so much specifically to you Al! You've been so helpful I'm not sure you realize!

Levi

Hi Levi,

You probably won't believe this, but I actually had composed a very much longer post than my above one (post #9 ) and had included checking out the ignition switch, the terminal markings on the back of it, which colour wires went to each terminal and what each wire was connected to, on the car. But I edited the post so as not to overwhelm you with too much information or things to check out.

I have heard of ignition switches 'having' to be replaced. These switches rarely gave trouble, but the wires connected to the rear of the switch can become loose/detached, especially if someone is working on something nearby and pushes against them.

My approach is always to check out a suspected faulty component before replacing it. In the above situation (ignition switch), I've often found the problem is actually a loose connection, not a faulty switch. Of course, anyone fitting the new switch will ensure that all wires are connected securely - problem now solved but was it a faulty switch or just a loose connection?
On occasions I've opened up the switch to examine the contacts. It can be opened easily, just prise out the wire clip on the rear of the switch. Often just a clean up, maybe a slight stretching of any springs fitted, reassemble and you're good to go. Incidentally, if you remove the switch part from the ignition switch unit, inside on the switch operating shaft, you might iirc, find a metal disc onto which is stamped a number, this is the key number for the ignition switch.

On some U.S. forums dealing with the 124 Spider, I've seen mention of people 'having' to replace the ignition switch. Apparently, some of these replacement switches have a slightly different number of terminals to the original fitment, which can cause some confusion, some say they are for the Lada cars. There's a big difference in price between one of the cheaper switches c. $80 versus a genuine Sipea switch @ c. $499? But I don't believe the cheaper switch is substandard in any way and I certainly wouldn't fork out $500 for a switch.

I'd suggest you check out the security of all wires on the rear of your ignition switch before replacing it. To do this, 1st, disconnect the negative (-ve) terminal on the battery. There is a soft plastic cover/shroud over the bunch of cables connected to the ignition switch. Hold the bunch of wires and ease the cover away to expose the wires, if you just pull the cover back, you'll likely disconnect one or more wires. You might need a mirror to see what you're doing. Check all wires are securely connected - if any are loose, remove them and squeeze the sides of the terminal slightly using a pliers and refit them.
Pay particular attention to the small blue with black wire going to terminal 15 - this is the live feed to the ignition coil. Also the heavy black wire going to terminal 30/1 - this is a live feed from the battery. The heavy red wire going to terminal 50 operates the starter motor. The heavy brown wire going to terminal 30 also feeds power to the ignition switch. These are the important wires as regards ignition and starter motor operation. These heavy wires and the blue with black wire are not fused, hence the warning to disconnect the battery lead before working on them - safety first!
If you decide to remove the ignition switch to work on it on the bench or to replace it - some of these cars have block connectors a short distance from the switch that can be disconnected leaving the wires still attached to the switch rear, if not the wires will have to removed - make a not of which colour wire goes to which terminal (the terminal no's are on the switch block).To remove the switch from the steering column, insert the key, turn to the 'Mar' position (i.e.'ignition on' position), locate and remove 2 or 3? Phillips head screws on the periphery of the switch, then wiggle the switch out.

Thermostat :-

Afaik, Autoricambi are just as good as Midwest-Bayless, similar pricing but Autoricambi do seem to specialize in the 124 Spider... Consider they may be getting their replacement parts from the same sources....

If the thermostat wasn't leaking, why not just re-use the rubber sealing ring? I've seen 2 types of rubber sealing ring, one is square-section rubber, the other is actually a 'U' section, this latter type needs to be stretched over circumference of the thermostat. I'm not sure if there is a paper gasket also used on your thermostat water outlet (it's different from the one I was describing as being in 2 parts). If there was no paper gasket there, there probably isn't one needed - Autoricambi lists a paper gasket (Sku GA1 - 401 @ $7.99) but it's out of stock. Autoricambi also list a thermostat (CO9 - 413) which opens at 180F. Midwest-Bayless list a thermostat but it opens at 160F, same as the one you have - however they say that this lower than stock opening temperature helps to improve cooling.

The thermostat you've fitted will probably be fine to use. I can't see in your pics if it has either a small hole or a hole with a 'jiggle pin' in the metal disc - either of these help to avoid air locks, assist with 'burping' the cooling system.
If neither is incorporated in your thermostat, I think I'd drill a small hole in the flat part of the metal disc of the thermostat away from the central working part - 3mm (1/8inch) would probably work just fine.

I'm afraid I can't advise on what size of bolts would replace the air injection? pipes in the cylinder head - this emission equipment wasn't used over here.
It's hard to judge from your pics but if I was to hazard a guess, I'd say 10mm. As Fiat generally use ISO-Metric fine threads, I'd be looking for 10x 1.25mm. The alternator adjusting bracket bolt is 10x1.25mm, you could maybe try removing one of the air injector pipes and try this bolt in the hole. If the thread is finer and tapered and approx. 10mm, it could be 1/8 inch BSP thread, a plumbing supplies stockist might have suitable plugs in stock.

However, see:- https://autoricambi.us/cylinder-head-air-injection-plug-set
(SKU: CHO-024 @ $26.99.) for a quick but pricey fix.

In summary, I'd drill a small hole in your new thermostat (it should work just fine) if there isn't one there already. Refit the thermostat using the original rubber sealing ring. Fabricate a paper gasket if there was one fitted originally, otherwise leave it out.

I'd check out the security of the wires at the rear of the ignition switch most carefully before buying a new switch. Even then, I'd try opening up the existing switch to check it out and try to fix it before ordering a new switch.

I'd remove one of the air pump pipes from the cylinder head and try to match it up with something standard. Are there any fastener (bolts, nuts etc.) or plumbing supplies stockist near to you - bring one of the air pipe fittings in, they should be able to match it up with a standard bolt/blanking plug.

Thanks for the 'thanks', always appreciated

Al.