1998 S90 blower replace when replacing blower resistor?

[93Regina]

What is a bad test going to look like?

Write down your results, and post....don't use K-ohm scale, just ohms.

[93Regina]

This is what my resistor looks like:

Not quite, here is what it really looks like below, which really is nothing more than this A/C Blower Motor Resistor For Chevy GMC Pickup Trucks shown.

So, you put one probe on that single wire, and touch the other probe to those other wires, when on ohm scale.

Now, if you need another resistor pack, do not buy one...there is another solution using PWM Actually, that GM resistor might work just fine also...have to spec out ohm rating differences, and if it will fit inside blower's air space OK.

.....

[jefflamonica]

Thanks, 93Reg. I'm sorry, I didn't understand your "duplicate post" comment. I'll definitely save that list of component codes.

[jefflamonica]

Write down your results, and post....don't use K-ohm scale, just ohms.

Will do. Thanks.

[jefflamonica]

This is what my resistor looks like:

Not quite, here is what it really looks like below, which really is nothing more than this A/C Blower Motor Resistor For Chevy GMC Pickup Trucks shown.

So, you put one probe on that single wire, and touch the other probe to those other wires, when on ohm scale.

Now, if you need another resistor pack, do not buy one...there is another solution using PWM Actually, that GM resistor might work just fine also...have to spec out ohm rating differences, and if it will fit inside blower's air space OK.

.....

The housing and connectors on the one on the left look similar. The guts are totally different on mine (the one the PO had removed from the car, and the used one he purchased, but never installed). Mine has the aluminum heat sink on the inside. I'll check the solution link you provided.

[93Regina]

I'll check the solution

Simple trouble shooting, but the fan switch needs to be put in each position, with key switched to on position, and then you check for voltage on each "colored wire" (4/40's wires).

[lummert]

This is what my resistor looks like: http://www.ebay.com/itm/260854741647?eu ... 32197&cp=1. Very different than so many I see. I'd have to pull the glove box to recheck, but I believe I had 2 wires going in on one plug and 3 on the other.

Your link shows the same resistor unit used on my 1988 Volvo 760.

[lummert]

Some useful info:
http://home.eol.ca/~clubshub/760start.htm

[jefflamonica]

Okay, it just got even weirder. I pulled the glove box and got to the blower resistor again. The except for the one plug on the left, none of the wiring colors match the diagram (smh). And the right connector which should have four wires going to it only had two. The used resistor only had 3 pins on that connection anyway. Here's the pictorial version:

The resistor

The plugs:

Then, below the blower, behind the knee bolster, I find these tow plugs connected to nothing.

Scratching my head now. Separate reply for the resistance test across the pins.

[jefflamonica]

While I had the resistor out of the car, I got out my digital pocket multimeter. It is autoranging. See the pic below for how this tested out. With the wiring colors, and the numbers of them totally off from the green book diagram, I'm at a loss.

Any guidance from here will be appreciated. I was hoping to be able to test input from the AC control unit's fan wires, but now, I can't identify them. Oh, I did use an incandescent test light on the three pins in the second connector at all fan speeds. No light, but the fan blows on full, regardless of switch speed.

I have ordered a used control unit, but not sure if it's in full working order. I needed the knobs, so the $25 was worth it, even if it sucks. But I have read there's a relay soldered to the board in the MCC. Can anyone confirm it acts as the high fan relay in previous models? I'm beginning to suspect, if that's true, that the relay on mine is stuck closed. But that still doesn't solve the mystery wiring situation. It doesn't look like anybody's been in there hacking.

Thanks.