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I would really try to find and fix the root cause first. If you try to add a manually-controlled switch to the cooling fan relay, you will likely be driving around with the 'ck eng' light on. . . .
I agree with I C on this matter.

1st: What is the year model, make and engine on your van.

2nd: What condition have you noticed that makes you want to override the electronic control of the radiator fan? Is the engine overheating at slow driving speeds or stopped idling? Is the A C system over pressuring, venting refrigerant because the radiator fans are not running?

Not knowing which model year you are referencing I looked at the radiator fan control circuitry for a 2010 and 2012 model year Grand Caravan. The wiring schematics were identical. It appears the TIPM controls a low fan speed relay and a high fan speed relay. I am guessing the TIPM receives communication signals from the PCM about radiator fan control. In the low fan speed relay load circuit there is a schematic box that identifies a resistor for providing an actual low fan speed. The high speed fan relay is wired directly through a fused circuit from the battery to the fans. Other than wiring connectors and the TIPM, the circuitry is not that complicated.

If you answer the basic questions we may be able to provide some guidance.
 

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Here is a link that shows the electrical schematic for the radiator fan motor. There is a radiator fan motor low speed relay and a radiator fan motor high speed relay and both are located in the TIPM (totally integrated power module). Switch the high speed relay and put it into the location for the low speed relay and test to see if the fan runs in low speed. If it does then you know the relay is good.

Notice that the power load for the low speed fan motor passes through a resistor. This reduces voltage and allows the fan to run at low speed. The high speed fan relay bypasses the resistor and provides full voltage to the radiator fan motor for high speed operation.

Dropbox - MiniVan 2011

Also is a chart is shown for fan operation. It is somewhat incorrect in that your vehicle does not have a feature which can continuously adjust fan rpm. Only certain vehicles (not in North America) have a pulse width modulated radiator fan motor. But the activation temperatures for fan control are probably still the same.
 

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From your problem discussion it appears the TIPM was changed by a dealer who shotgunned parts and did not properly diagnose. You have changed the high speed fan relay and the problem persists.

Have you checked for any diagnostic trouble codes in the PCM (powertrain control module)? There might be codes that pertain to a fan relay circuit such as open, shorted, etc.

Your problem is NOT with the TIPM control to the high speed fan relay. Look at the schematic link that I provided. You need to check the wiring from terminal #4 at the high speed fan relay socket on the dark blue / violet tracer wire. The label S134 is a splice. You need to find that splice and make sure power is going through it. It could be corroded. Then continue to follow this wire where it splices into the output wire of the low speed fan resistor. I bet you will find a wiring problem and there is no problem with the TIPM control of the high speed fan relay.
 

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. . . . No i have not looked at the codes because i do not have a reader and anywhere you take it, they say that you have to have a check engine light on to read it. If i take it to dealer to have it read, they charge me $140.
You can take the vehicle to Autozone and you can ask for a diagnostic readout with a portable, hand held code scanner. This is a free service. The CHECK ENGINE lamp does NOT have to be illuminated to interrogate the PCM. Now if the CHECK ENGINE lamp is not illuminated it is very possible that there are no active stored codes and the scanner will indicate accordingly. But some scan tool readers can note if there are any historical codes.
 

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Do you know what code scanner in particular can read historical codes because every time I go to Autozone they also say that the check engine light has to be on
There is NO physical nor technical reason that any code reader / code scanner cannot retrieve codes from the PCM. Typically when a repair is made to a sensor or device or wiring connector that generated a particular diagnostic code, you make the fix. Then you use the scan tool to erase the code. You operate the vehicle for a period of time and then check the diagnostic memory of the PCM for reappearance of any diagnostic codes. If you have performed the proper fix, the tool should indicate no code present.

To say that one cannot retrieve any codes unless the CHECK ENGINE lamp is illuminated has to be a silly rule. There is no logical or engineering rule designed into the system to prevent this process.

My local Autozone uses an Actron code scanner for this service. It is more sophisticated in addition to reading codes, it provides limited capability in monitoring live data from the PCM. It also will read historic codes. A simpler code retriever might not be able to interrogate that part of PCM diagnostic memory that stores historical information.
 

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I am driving a 2011 Dodge Grand Caravan. Are you saying that the schematic is for a PT? I uploaded a schematic to my drop box I got figure out how to link it to here
I made no mention in any of my posts about a PT Cruiser. The link I provided in the post on Saturday, Oct 15 is schematic for a 2011 Chrysler built minivan. You need to check the wiring from the high speed relay for opens and shorts. Label S134 in the schematic is a wire splice. That needs to be located and checked for electrical continuity and no corrosion and no broken wires.
 

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This appears to be the standard type, stand alone relay and mating socket that Chrysler used on all its vehicles from the late 1980s through the early to mid 2000 time frame. Any female, pigtail connector used for the ASD, fuel pump, A/C clutch, etc from this era will fit. So surely you can find this connector at a Chrysler vehicle "bone yard".

Here is a link to an Ebay item for the female connector. This should be a suitable replacement.

http://www.ebay.com/itm/like/162186683212?lpid=82&chn=ps&ul_noapp=true

Note that there are 5 female receptacles in this generic replacement. If you look at the picture of the receptacle you provided that is damaged, there is no connector for the center terminal on the relay. It is not used. So you can ignore the wire to the center terminal in this replacement.
 

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Seems to go right along with how the Computer overcharges the batteries causing them to eventually go bad. this is a battery i put in here 2 months ago and immediately it started to bubble a little at the top. had to replace TIPM, or at least Dodge charged me for a TIPM after computer was charging battery with 18 volts
I do not want to aggravate your displeasure with problems getting your van serviced properly. But any knowledgeable service facility should realize that an overcharging condition of 18 volts almost certainly points to an alternator / generator field circuit that has full 12 volts applied to it. That would necessitate a close inspection of the wiring for the generator field circuit and looking for a short to ground. In normal operation the PCM pulses the generator circuit ON / OFF quickly and that regulates the charging output. The TIPM is not involved with regulating generator output. Seems this repair facility is less than stellar and likes to "fire the parts cannon" to fix things.
 
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