Heater Core Replacement

[93Regina]

1988 760...ECC.

There is an ECC Power Unit, which appears to use ground potential to change fan speeds.

The fan appears to be supplied with a hot 12 volt wire, that goes thru fuse 11/28, and then to battery. Around the battery, there might be a wire with a "VO" color, whatever that is. I would check wires coming off battery and forward there to make sure they are fit for duty. And, I would clean up fuse 11/28 terminals.


At ECC Power Unit, there is a SB colored wired...that goes to that grounding block...I would attach an additional ground, in that clip, to that wire.

Needless to say, I'd pull ECC' Power Unit connector, and clean it up too with electrical spray

Hence, you have to have full current for fan, and it must be grounded. If a good ground and current exists, then your ECC power unit may be the issue.

On passenger side, there is a grounding block; I would clean it up

[1997V90BGG]

Thank you all, that's good information. A couple of more questions.... So it appears that i have to take the ACC assembly apart in order to access the heater core. Does the information on disassembly apply to a 1997 as well? i.e. taking apart the center console and a portion of the distribution box to access the heater core?

The AC and the heater has not been functional since I bought the car although the defroster worked until recently. Is it likely that some of the vacuum servos or vacuum hoses may be leaking and therefore make the climate control non-operational? I mean is that the most common issue with the ACC units?

Is the 960/V90 also an "Interference" motor? Timing belt replacement also very critical as it was in my 850?

I apologize for my inexperience but this is only my 2nd experience with repairing or working on a Volvo and it's a bit overwhelming at times.

[93Regina]

Is the 960/V90 also an "Interference" motor?

If it is a 6-cylinder in-line DOHC, I would suspect so.

Volvo says, "Volvo V90 Wagon was introduced during the model year 1997 as a replacement for the Volvo 960 Wagon.

When we compare the two models, we only find minor differences."

[lummert]

Is the heater core leaking?

[lummert]

It may be of some interest that the heater blower motor from a 1995-2005 Pontiac Sunfire (and every GM car it interchanges with) is a direct fit for a 1988-1990 Volvo 760, 1991-1992-940SE, 1992-1997 960. The wiring harness plug may differ but that's not a big issue.

[1997V90BGG]

Yes, the heater core is leaking. I pulled the knee bolster panels and exposed the area behind the center console and I can see coolant drops. So now I need to start peeling back the layers so I can get to the core. (pun intended) .

Is the manual excerpt post from the 1994 960 a good reference for getting to the Heater core? Just curious about the order of disassembly.

[93Regina]

manual excerpt post from the 1994 960 a good reference

OEMs generally design something, and make few, if any, production changes over time. When a change is made, there is usually a darn good reason. OEMs may make cosmetic changes, different trim, etc., but "under the hood" stuff rarely changes.

As Volvo stated, "When we compare the two models, we only find minor differences."

Volvo manufactured engines and bodies, most all of the other stuff was bought from other suppliers, which is the way many OEMs do it today; years ago, an OEM may have made most all of the parts/etc, for a vehicle, but these days, many parts are bought from other vendors.

[1997V90BGG]

Great, thank you. I'll keep you all posted on my progress.

[93Regina]

I'll keep you all posted on my progress.

Find out what shop time is for replacing the heater core, before you begin work.

A Volvo 240 Heater Core Replacement gives about 8 hours for an experienced mechanic.

In engine compartment, I would by-pass heater hoses, until work is done.

Btw, those documents cited can be downloaded...at top of page, there is a download symbol

Take your time...