BCM speed question. Swapped, no full blast

[Turbov6Bryan]

Sunday lost all fan speeds, zero air movement out of vents.

Yesterday I swapped in a used BCM from a wrecked marauder that I have, at least I have AC blowing out again. Yay!

So, say there's 5 speeds of the fan, low being 1 and high being 5. This used BCM seems to lack the highest most powerful speed???

Is it possible to lose certain speeds?

I used google, found the spot I need to solder on the bad one I removed that zero speeds work

What can be done to get highest speed back on the one currently in the car?

Fan speeds adjusts fine, just missing highest of highs.

Thanks

[fastblackmerc]

Fix the one you put in. If you send me both of them I'll fix one and send it back.

[RF Overlord]

All speeds other than full are PWM-controlled through the switching transistor. To make full speed, a relay is closed that bypasses all the other circuitry. It's possible the one you have now either has a bad relay or the circuit that drives it is fubar.

[Turbov6Bryan]

Ok thanks guys I will do some work this weekend

Appreciate it!

[Comin' in Hot]

Subscribing, I have the same issue right now

[8UWITH6]

Because DTR haha

[Comin' in Hot]

Because DTR haha mines because of almost ZFG.... Very low on my list of things to fix.

[MyBlackBeasts]

Sunday lost all fan speeds, zero air movement out of vents.

Yesterday I swapped in a used BCM from a wrecked marauder that I have, at least I have AC blowing out again. Yay!

So, say there's 5 speeds of the fan, low being 1 and high being 5. This used BCM seems to lack the highest most powerful speed???

Is it possible to lose certain speeds?

I used google, found the spot I need to solder on the bad one I removed that zero speeds work

What can be done to get highest speed back on the one currently in the car?

Fan speeds adjusts fine, just missing highest of highs.

Thanks

Ck fuse #103 & relay #301 in the under hood PDM.

[Turbov6Bryan]

Subscribing, I have the same issue right now

Post #3 makes says it all, all speeds other than WOT are pulsed with electricity to give a less than 12 volt juice

When WOT is needed, relay is in charge....

Relay or circuit. Add copper to it and new relay, or clean contacts

Thanks for the help fellers!

Neil.... LOL. U b jelly

[RF Overlord]

Ck fuse #103 & relay #301 in the under hood PDM.If either of those were the problem, he'd have no blower function at all.

[Blackmobile]

Doesn't RockAuto offer a new replacement?

[Turbov6Bryan]

Doesn't RockAuto offer a new replacement?

Yes they are about 25.00 and fail just like the factory ones


Little bit of copper wire and solder fixes the issue.

[Blackmobile]

Fixing one, no problem. When the 2nd one goes out, a new replacement is a nice thing to have.

[Turbov6Bryan]

Fixing one, no problem. When the 2nd one goes out, a new replacement is a nice thing to have.

Sad is on my DTR those heater hoses are soooo close to the BCM I had to remove the damn hoses to slide it out. What a joke.