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Dodge Repair/'06 300:Fog lamp control circuit open: '06 300/magnum B1661


Hello Roland,
I just checked on that IPM and FCM circuit between pin 26 and pin 85 of the relay socket,there is no link,no continuity.
Looks like that power module could be opened to me,no ?
Maybe it is possible to relink,I haven't taken apart one of these power box yet.
Anyway,I have found my problem and it is a good thing,just have to find the cleanest solution because I might sell the car next spring.
What would be the cost of a new power box,just for curiosity.

The connection from pin 26 of the FCM to pin 85 of the fog lamp relay socket is of course necessary for the relay to be activated. I must mention that it is not clear whether the connection is between the pin of the fcm socket or the same pin # of its plug, though I would believe it is the pin of the plug, but before doing anything I would check for continuity to the relay pin from both the plug and the socket. If neither then the integrated power module has to be opened up to see if you can find the 'break' in the connection or the entire module replaced. Only a dealer parts counter would have the cost information.
Thanks for the rating/nomination/ and very kind remarks.

History:QUESTION: Hello,
My car is a 2006 dodge magnum R/T,I have this code:
B1661 Fog lamp control circuit open
The power side of the circuit is woking fine,I need help from an expert please.

ANSWER: Hi Terry,
The fog lamps are powered by fuse #7 (20 amp) in the integrated power module and that fuse feeds both the fog lamp relay control coil and when the relay closes it feeds the lamp wiring.
So the first thing to do is check whether when the fog lamps are requested (by a helper) does the fog lamp relay click (listen/touch). It too is in the power module box. If it doesn't then it could be either the fog lamp switch or the wiring from the front control module of the IPM to the relay actuation coil, or the relay itself could be out of order. You could try switching the relay with another one of the same part number and then test if that relay also doesn't close or does it?
I hope it is the relay because if it still won't work with a known good relay then the 1661 code seems to point to the need to replace the entire integrated power module!
Let me know and I can give you more details about the control circuit. Also, what do you mean by the "power side of the circuit is working fine"?

---------- FOLLOW-UP ----------

QUESTION: Hello Roland,
I did check the fuse and it's ok,the relay is also ok but it did not click while resquested from the switch but the fog lamps light came on the dash every time,I did those test just forgot to mention them to you.
I didn't know how to check the dash switch so I bought a new one(80$)and it is still not working so I guess we head toward that IPM.
What is the difference between the IPM and the FPM ?
I will not change that module for a fog lamps problem but you can give me more details about the control circuit for me to check,I have access to the OTC EVO scanner.
"power side of the circuit is working fine",what I meant was the power side of the fog lamps from the relay was fine, I did jump with a fused wire from 87 to 30 and they lighted up.
My idea is in case of a module problem to use the dash switch to feed the control side of the relay to solve the problem ?

ANSWER: Hi Terry,
The front control module (the part of the integrated power module next to washer fluid bottle) is what activates the fog lamp relay via its getting a digital message from the headlamp switch. It has a 49-pin connector and the pin #26 of that plug is supposed to be connected to pin 85 of the relay socket. It should ground the relay activation coil to close the lamp relay. So verify whether pin 26 is connected to pin 85, and if you can see what its voltage reading is when the fogs are "off" and when requested to be "on". If it is then for some reason the variable voltage signal from the headlamp switch is not being "read" as the fog request position, but with a new switch that should not be the cause. Thus the 1661 'solution' of replacing the entire IPM!
So I would not try to mess with the new headlamp switch or its wiring. You would likely malfunction the other switch positions if you did that. Rather you could wire in an accessory switch at the dash that is connected to pin 26 of the fcm which then grounds pin 26 when you close the switch.

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Roland Finston


Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

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