Replaced blower motor (positive wires hot at relay)

[TrueTexas]

Hey y'all. I replaced the blower motor with a Valeo blower. (Bought from Amazon - could be counterfeit, although it installed perfectly and looked exactly like the one that came out albeit an interesting sticker on it)

Install was fine and was about to put in the new resistor. Ran the fan on high (only speed that works right now) and noticed both the red and green wires at the positive side blower motor relay started to get pretty hot to the touch quick.

Quick question before I order an ammeter with enough range to check how many amps this new blower motor is pulling.

For those of you with a newer blower motor...

how hot do the main power leads to the relay behind the glove box get? Do they remain cool or do they warm up considerably when the fan is running?

 

[Daryl]

Hey y'all. I replaced the blower motor with a Valeo blower. (Bought from Amazon - could be counterfeit, although it installed perfectly and looked exactly like the one that came out albeit an interesting sticker on it)

Install was fine and was about to put in the new resistor. Ran the fan on high (only speed that works right now) and noticed both the red and green wires at the positive side blower motor relay started to get pretty hot to the touch quick.

Quick question before I order an ammeter with enough range to check how many amps this new blower motor is pulling.

For those of you with a newer blower motor...

how hot do the main power leads to the relay behind the glove box get? Do they remain cool or do they warm up considerably when the fan is running?

The only component that’s okay to get warm is the blower motor resistor, that’s why it mounted in the ducting so the airflow from the blower motor keeps the heat down. You have a bad connection at whatever area the wires are getting hot.

 

[TrueTexas]

The only component that’s okay to get warm is the blower motor resistor, that’s why it mounted in the ducting so the airflow from the blower motor keeps the heat down. You have a bad connection at whatever area the wires are getting hot.

Thanks @Daryl

Ground side of the circuit is cool so I believe you are right.

I've only checked right at the positive side relay location. I did have to repair the wires at that relay harness when I purchased the Jeep so it's highly likely the connectors in the relay harness are bad. The relay itself is getting pretty warm as well.

I'm gonna go check the rest of the wiring to see if it is cooler further away from that connector. If so, I'll put in a new relay harness.

 

[TrueTexas]

So the ground side is hot at the blower motor switch as well. I also had to fix that as it was melted when I got the jeep.

Think I'm gonna go ahead and wire in the high current bypass wiring that I built and the positive side relay harness. If it keeps getting hot, I'll check to see how many amps the new motor is pulling.

 

[98TxTJ]

Hey y'all. I replaced the blower motor with a Valeo blower. (Bought from Amazon - could be counterfeit, although it installed perfectly and looked exactly like the one that came out albeit an interesting sticker on it)

Install was fine and was about to put in the new resistor. Ran the fan on high (only speed that works right now) and noticed both the red and green wires at the positive side blower motor relay started to get pretty hot to the touch quick.

Quick question before I order an ammeter with enough range to check how many amps this new blower motor is pulling.

For those of you with a newer blower motor...

how hot do the main power leads to the relay behind the glove box get? Do they remain cool or do they warm up considerably when the fan is running?

I had that problem to the point it was destroying relays. The ground wire from the relay to the body mount was undersized, perhaps a mistake by the PO.

After a year of chasing a variety of blower issues, putting in a proper sized ground wire from the relay to ground corrected all issues.

 

[TrueTexas]

@98TxTJ the relay that is getting hot is on the positive side of the circuit.

See the attached pic.

The only ground in that relay is the thin black wire and it, along with the 12v+ blue and white striped thin wire just powers the coil to close the contact between the red and green wires which are the high current ones. At most that thin ground wire is carrying 600mv and it doesn't get hot. Just the red and green get hot.

The heat is definitely originating at the relay or relay harness and spreads out on both the red and green wires.

I did install the harness that I made in the pic above and a new blower motor resistor and the switches are now cool. But the ground at the relay in the harness I made is pretty warm and the positive side relay is still getting super hot.

I think the next steps for me are
1. Try another relay in the 12v+ side
2. Buy an ammeter to check how many amps the new blower motor is pulling
3. Replace the entire 12v+ relay harness and relay or try another blower motor.

What sucks is that I was able to find a Valeo blower (OEM) for under $50. Maybe it's cause it's a fake and belongs in the trash.

 

[TrueTexas]

Regarding the steps I have taken so far:

1. New relay - no change
2. Testing with ammeter

Speed 1 - 3.6 amps
Speed 2 - 8.46 amps
Speed 3 - 16.6 amps
Speed 4 - 23 amps

Does this should too high on speed 4?

Thought I read somewhere that is should be pulling 15 amps max.

 

[TrueTexas]

This is starting to drive me

So I replaced the motor (again) with a new Mopar p/n 4886150AA.
The new motor is pulling almost exactly the same current draw as the previous motor

• I don't think it is the blower motor.
• Maybe 23 amps at high speed is "normal"

My issues continues to be:
Wires are still getting hot at the relays on the 12V+ and 12v- sides.

• The 12V+ is getting hotter than the 12V- (by feel only).
• The ground getting hot is not due to my bypass wiring as the ground side switch was getting hot before I installed my bypass harness, it has now just moved to the relay

The only thing I can think of is high resistance at the 12v+ relay.

I welcome any and all thoughts you may have.