Could of fooled me ..I thought I had it fixed
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So Cal Mark
Re: Could of fooled me ..I thought I had it fixed
the easiest ammeter to use is one that has an inductive pickup; it will just clamp around the wire to show amperage. Very quick and easy to use.
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spider2081
- Patron 2024
- Posts: 3015
- Joined: Fri Jan 27, 2006 11:45 pm
- Your car is a: 1981 Spider 2000
- Location: Wallingford,CT
Re: Could of fooled me ..I thought I had it fixed
If I follow what is happening, did you say the fan runs if you connect power and ground to it?? If it does and it sounds normal and seems to have suffidient speed I doubt it is a problem. Your sympton of the circuit blowing the fuse only when the temperature switch is in the circuit sounds to me like the switch is connected between the power wire for the fan and ground instead of between the other side of the fan and ground. If you have a volt meter or trouble light, identify the wire that has the 12 vdc on it that is protected by the fuse that is blowing. To do this you connect either the light or voltmeter to the wires till you have a positive voltage. Then remove the fuse and see if it goes away. This wire connects to one side of the fan motor. the other side of the motor conects to the fan switch. The other side of the fan switch connects to ground.
On some Fiats its possible to swap the windshield washer pump connector with the fan connector. Not sure what the symptom is when this is done though.
I don't think you pave enough evidance to replace a fan yet.
Good luck
On some Fiats its possible to swap the windshield washer pump connector with the fan connector. Not sure what the symptom is when this is done though.
I don't think you pave enough evidance to replace a fan yet.
Good luck
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joelbert2k
Re: Could of fooled me ..I thought I had it fixed
gopapa,
From reading over this thread I am suspecting that a PO misswired the whole fan/switch/horn setup. One of the things that needs to be addressed is whether this is a hard short or an overloaded circuit. If it is a hard short than the fuse will blow so fast it will look almost like a flash bulb going off. That would indicate a direct short to ground. On the other hand if it's an overload then, since we know that the fan works, the fan blades should move at least a little before the fuse goes.
If you look at the wiring diagram for the fan/switch there is no way for a hard short to be activated by the switch. Since power goes to the fan first and then thru the switch to ground a short to ground anywhere would either blow the fuse all the time or cause the fan to run constantly.
Make sense?
Joel
From reading over this thread I am suspecting that a PO misswired the whole fan/switch/horn setup. One of the things that needs to be addressed is whether this is a hard short or an overloaded circuit. If it is a hard short than the fuse will blow so fast it will look almost like a flash bulb going off. That would indicate a direct short to ground. On the other hand if it's an overload then, since we know that the fan works, the fan blades should move at least a little before the fuse goes.
If you look at the wiring diagram for the fan/switch there is no way for a hard short to be activated by the switch. Since power goes to the fan first and then thru the switch to ground a short to ground anywhere would either blow the fuse all the time or cause the fan to run constantly.
Make sense?
Joel
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GOPAPA
Re: Could of fooled me ..I thought I had it fixed
Yes ! when I unhook the switch and hook the fan up directly to my batter charger it runs real fast ,,or as fast as it supposed to run ,,I guess. I will refer back to your post to do the checking in a couple of weeks , thx papaspider2081 wrote:If I follow what is happening, did you say the fan runs if you connect power and ground to it?? If it does and it sounds normal and seems to have suffidient speed I doubt it is a problem. Your sympton of the circuit blowing the fuse only when the temperature switch is in the circuit sounds to me like the switch is connected between the power wire for the fan and ground instead of between the other side of the fan and ground. If you have a volt meter or trouble light, identify the wire that has the 12 vdc on it that is protected by the fuse that is blowing. To do this you connect either the light or voltmeter to the wires till you have a positive voltage. Then remove the fuse and see if it goes away. This wire connects to one side of the fan motor. the other side of the motor conects to the fan switch. The other side of the fan switch connects to ground.
On some Fiats its possible to swap the windshield washer pump connector with the fan connector. Not sure what the symptom is when this is done though.
I don't think you pave enough evidance to replace a fan yet.
Good luck
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GOPAPA
Re: Could of fooled me ..I thought I had it fixed
I will just have to do the process of elimitaion I guess to get it solved and after I buy me a good amp meter ,,the kind that Mark ,,I believe suggested I will start my testing and I will get back to you and all with the results. thx for the interest,, papajoelbert2k wrote:gopapa,
From reading over this thread I am suspecting that a PO misswired the whole fan/switch/horn setup. One of the things that needs to be addressed is whether this is a hard short or an overloaded circuit. If it is a hard short than the fuse will blow so fast it will look almost like a flash bulb going off. That would indicate a direct short to ground. On the other hand if it's an overload then, since we know that the fan works, the fan blades should move at least a little before the fuse goes.
If you look at the wiring diagram for the fan/switch there is no way for a hard short to be activated by the switch. Since power goes to the fan first and then thru the switch to ground a short to ground anywhere would either blow the fuse all the time or cause the fan to run constantly.
Make sense?
Joel
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GOPAPA
Re: Could of fooled me ..I thought I had it fixed
I will take your advice and buy it .. thx papaSo Cal Mark wrote:the easiest ammeter to use is one that has an inductive pickup; it will just clamp around the wire to show amperage. Very quick and easy to use.
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
Re: Could of fooled me ..I thought I had it fixed
I think you problem is a combination of: The power and ground wires for the fan are switched, and you probably have a bad ground connection.
You should have a ground pod "bottle cap" on the drivers side fender. Ther should be one thick black wire comming off it. That wire goes to the fan switch at the bottom of the rad, then back out the switch and up to the fan. The other wire comming out of the fan is the 12V power wire, it thinks its light blue. It should have 12v at all times.
The absolute FIRST thing to do is: Remove the ground pod and clean it till it is bright shinny metal, same with the area it touches around the stud, bright shinny metal. Second is to check all the connectors and wires in the ground circuit. I've had intermittent fan opperation due to a loose connector, even when the connector was brand new. Third is to do what Mark said and clean the fuse pannel and install a new fuse.
You should also make sure your fan is hooked up properly. If you got 12v at the blue wire, hook it to one of the fan connectors, then jumper a ground wire from the other connector to the ground pod. The fan should come on and stay on as long as you have it hooked up. CAREFULLY feel behind the fan, the fan should be pulling air through the rad, and blowing it towards the rear of the car. If it is blowing the opposite direction then the wires are switched.
A final possibility is that the fan motor brushes are wearing/worn out. You can take the fan motor housing apart to check the length of the brushes, at the same time take some alcohol/naptha/electrical connector cleaner/acetone etc. and clean the contact area where the brushes contact. A good starter/alternator rebuilder should be able to get the brushes for under $5 if thats the case.
You should have a ground pod "bottle cap" on the drivers side fender. Ther should be one thick black wire comming off it. That wire goes to the fan switch at the bottom of the rad, then back out the switch and up to the fan. The other wire comming out of the fan is the 12V power wire, it thinks its light blue. It should have 12v at all times.
The absolute FIRST thing to do is: Remove the ground pod and clean it till it is bright shinny metal, same with the area it touches around the stud, bright shinny metal. Second is to check all the connectors and wires in the ground circuit. I've had intermittent fan opperation due to a loose connector, even when the connector was brand new. Third is to do what Mark said and clean the fuse pannel and install a new fuse.
You should also make sure your fan is hooked up properly. If you got 12v at the blue wire, hook it to one of the fan connectors, then jumper a ground wire from the other connector to the ground pod. The fan should come on and stay on as long as you have it hooked up. CAREFULLY feel behind the fan, the fan should be pulling air through the rad, and blowing it towards the rear of the car. If it is blowing the opposite direction then the wires are switched.
A final possibility is that the fan motor brushes are wearing/worn out. You can take the fan motor housing apart to check the length of the brushes, at the same time take some alcohol/naptha/electrical connector cleaner/acetone etc. and clean the contact area where the brushes contact. A good starter/alternator rebuilder should be able to get the brushes for under $5 if thats the case.