Coolant light on - can't see problem, random connector not connected

Hi

Well the 960 has been in the shop for a week getting some much needed replacements for shocks and brakes, it's had its radiator done this year, thermostat the previous year and the A/C system fully checked and a pipe replaced.... But now we're getting the coolant light coming on - only at startup and very rarely, we've topped up the coolant, but we can't see any leaks.... I drove it for an hour to dry off the car (my dad washed it, so we couldn't tell if the water at the bottom of the rad was a leak or water from the car wash) then I let it sit for an hour and the car was dry, no leaks.... Coolant level seems to be where we topped it off to. When I was looking under the car tho, I noticed a cable and connector dangling (protected by the plastic plate under the radiator), it was running parallel to the wires which feed the horns.... The connector was near the miniature radiator for I guess the A/C system as metal pipes were feeding into it, I couldn't find a plug to stick the connector into tho. Does any one know what that connector is for??

If my coolant level drops I know it could be a failed head gasket (if the plumbing isn't leaking) - but I don't notice any white smoke even under hard acceleration, temperature stays level at all times I haven't started monitoring coolant levels but i'll be checking all this week and for a while to come.

Another thing i've noticed is the rad fan isn't coming on, now it could be because it is still 0°-3°C outside today, so I don't know if it would - I tried turning the A/C on, but I don't think the ECC kicks on the A/C compressor when it's that cold outside.

Reply to
Rob Guenther
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rob...check grounds...i think the coolant light comes on when the curcut is grounded...is the plug "in" under the coolant bottle??

Reply to
~^ beancounter ~^

No, the plug is on the other side of the car (drivers side) the coolant is on the passenger side hidden under the black housing of the ABS system cover... This mystery plug travells with the wires for the horn and terminates near the radiator A/C mini-rad (condensor? evap?)

Reply to
Rob Guenther

If the "mini rad" is underneath the radiator it is for cooling the engine oil. This arrangement is used on 940 diesels as well. Perhaps it is for the engine oil temperature or is one of the sensors which use air-con pressure to switch on the cooling fan or even the thermal switch wiring for the fan. There are two relays and three sensors involved in switching the fan.

Cheers, Peter.

Reply to
Peter K L Milnes

Hmm could be for engine oil I suppose (i'm an electrical guy, not mechanical/fluids type person).... Wasn't that warm when I touched it but I let it cool off for a while... Is there not a cooler for the transmission oil as well? (or is that built into the main radiator?).... How many rads does this darn car have? I don't want to see how many a turbo model would have (main rad, this mini rad, and an intercooler??)

Is there a manual way to switch on the cooling fan? I can't get it to come on (and I drove the car HARD on the highway to try to get the engine running hot enough... perhaps it had cooled down sufficiently when I stopped to check it tho)

Reply to
Rob Guenther

"Rob Guenther" skrev i meddelandet news:UeeNd.7287$ snipped-for-privacy@news20.bellglobal.com...

I think the car has three rads: Engine coolant Transmisson fluid A/C condensor

I don't think it has a rad for the engine oil.

/Erik Lidén

Reply to
Erik Lidén

Erik, the coolant and transmission fluid coolers are in the same radiator unit. In cars with turbo, intercooler and air-con the three rads are coolant/transmission cooler, Intercooler and air-con condenser. On Turbo diesels with intercooler and air-con there are four rads with manual gearbox and four with automatic gearbox. Without air-con there are three rads with diesels. There is an additional small cooler which can be included in the transmission cooler piping run on automatic cars.

Cheers, Peter.

Reply to
Peter K L Milnes

The sensor that turns the low coolant light on is in the expansion tank (where you top up and check coolant level). They often go bad in this fashion. If the light disturbs you, pull off the wire on the sensor until it's replaced. (Or for really cheap people, just leave it that way.)

The miniature radiator is probably the engine oil cooler. Is it the full width of the rad, and 2-3" high with one hose going into each end?

The rad fan only comes on when necessary to cool the rad and/or condenser. Once you're going more than about 50 km/hr, there's very little chance the rad fan will need to come on. The engine computer controls the fan while monitoring coolant temperature, and with the grill removed you will see a cluster of 3 switches in the bottom corner of the condenser. These are set to 3 different pressures - the lowest pressure turns on the fan at low speed, the middle pressure, high speed, and the high pressure one turns off the compressor so the A/C system doesn't blow up or vent the refrigerant. When the temperature is below about 5 C, the refrigerant pressure drops such that the low pressure switch on the receiver-drier stops the A/C from coming on.

If you want to see if the rad fan will come on, then let the car idle for a while after it's warmed up. A piece of cardboard to inhibit flow through the rad during this test will speed things up.

The dangling wire may be for an outside temperature sensor, if the terminals are round. They often get removed during parking curb encounters.

Reply to
Mike F

Excellent, THANK YOU for your post, you answered all I needed to know.

Yes that connector has round terminals, I was thinking it may be for a temp sensor.... the 960's of 1993 didn't have a dashboard option for an outside temp gauge as far as I know, but could this be the pre-wiring for one? - or did some models have this? (We don't have the 'snowflake' light of the 850's mentioned in our manual nor visible on dash, nor is there a place for a thermometer).... Or is this sensor for the engine?

It was colder then 5C out, no wonder my A/C couldn't kick on, I was right telling myself it was a smart system, and wouldn't kick on if it was cold enough outside.

I let the car idle for 5-10 mins and it didn't kick in... I can't let a car idle for very long - I don't think it's a good idea for the engine (I don't believe oil pressure could possibly be being built up properly with only idle speed), not to mention idling causing environmental problems.

I did check out those 3 sensors, that's what I originally thought was leaking (turns out, not) - good to know what they do, now.

Cooler is exactly as you describe - nice to know this car has so much cooling capacity! No wonder it never gave us trouble at 35C pulling a trailer up the Cabot trail.

I t>>

Reply to
Rob Guenther

yep Rob...the 940's are pre wired for the o/s air temp guage...i poped one into my 940 for around $50...nice lieele extra feature...it has the orange snowflake around freezing temps...just plug and play.. ;-)

Reply to
~^ beancounter ~^

So I buy a sensor, then buy a little light cluster to go into one of the "idiot light" blanking spots in the dash?.... How do you install that in there? And where can I get it, the dealer?

Reply to
Rob Guenther

There was a temp gauge option that fit in the lower left corner of the instrument cluster (just to the left of the warning light row) for 88-

760s, 91- 740s and all 900s. It consisted of a little lcd display, wiring harness and the sensor. I guess some of the later cars didn't need the harness.
Reply to
Mike F

rob...it will show the current o/s air temp (while the ign is on) and when it dropps below freezing...the small, orange snowflake will "appear"...let me look in my garage...i have either the small readout window (that pops in the dash), or the other end...small sensor that plugs into the wiring harness @ the front bumber...then pops into ths small round hole "up front" in the plastic air damm, or mud barrier....

Reply to
~^ beancounter ~^

"Peter K L Milnes" skrev i meddelandet news:cu6acd$2m1$ snipped-for-privacy@sparta.btinternet.com...

transmission

I Don't know about the US, but in Sweden the 960 does not exists as either Diesel or Turbo.

/Erik Lidén

Reply to
Erik Lidén

All of the 960's has outside temp guage here in sweden... Maybe Volvo didn't think it was necessary for US to have those.

/Erik Lidén

Reply to
Erik Lidén

Reply to
Rob Guenther

Reply to
Rob Guenther

it was part of my cold weather package...ie: heated seats, heated mirrors, o/s air temp guage... here in denver colorado.....i just checked my garage...i have an un opened "sending unit"..the part that plugs into the open wiring harness...and pops into the front undercarrage...this has the sensor in it... i will ship it to you for, say $15 freight included...if you want to pay pal me $$...@ snipped-for-privacy@bonilla.com

then, you would just need the other end, or part that pops into the dash...there is already a small plate that comes out (lower left of insturement cluster...behind the glass)...and the read out unit pops in...it is lit for night use also...you would want to order the part from >>

john sharisky @ boston volvo village snipped-for-privacy@retailer.volvo.com

richard colorado

Reply to
~^ beancounter ~^

Hmm, temping offer, but I think I'll have to take a pass.

Thank's tho!

Reply to
Rob Guenther

that's cool Rob...if anyone else want's it...it is "in the box" and ready to go...

Reply to
~^ beancounter ~^

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