Pontiac Owners Club UK

Can anybody tell me where the blown air comes out when there blower vent setting is set to max ? Please?

Im trying to solve why air always blows out from the flap under the dash (ducting removed from the box) even if the controls are set to off and fan is on low speed.

my 73 transam hasnt got a max setting do you mean the high setting on the fan??? if you post a photo of your heater panel i will check against mine and see if i can help as my car still has fully working aircon but the low speed fan works all the time.

Jeff73 wrote:my 73 transam hasnt got a max setting do you mean the high setting on the fan??? if you post a photo of your heater panel i will check against mine and see if i can help as my car still has fully working aircon but the low speed fan works all the time.

I think the later 2nd gens had some extra modes for the aircon/blower system. I have off,max,bi-level,normal,vents,defrost and heat. I then have 4 fan speeds with low being on all the time.

Below the dash on the passenger side is the heater box assembly which usually has ducting attached to the front. My ducting is currently missing and I can see the large diverter door on the front of the box. It never fully closes even with the control set to off. It's all vacuum controlled as opposed to cable. The only cable control is to select cool air or hot air which controls the diverter door to the heater matrix.

I have a feeling that with off selected the large diverter door should be fully closed and not allowing any air into the car. When on max I think that door should open wide. It stays partially closed/open on this setting so something must be adjusted wrong or failed.

I'll certainly get some pics as soon as I can

Asked robin yet could be the water bottle is low on coolant top tip

thirdgen wrote:Asked robin yet could be the water bottle is low on coolant top tip

No I've not asked Robin yet if Ive not sorted it by the time I visit ill get him to have a look.

The water bottle tip was a top tip. Low coolant can mean a hotter engine. Once the petrol gets above a certain temperature it can cause detonation/pinging regardless of timing being correct etc. due to the nature and design of these Pontiac engines and electrics it's more common than you think. The temperature switch or sender is located high on one of the cylinder heads, and with no coolant level sensor the level can drop low inside the radiator without any signs. The water pump will then Struggle to pump the lower volume of coolant to the higher parts of the engine where the sender is. The sender can give a reading to the gauge which shows normal or even low as only the block heat conducts to the sensing tip, but in reality the coolant passage is only full of air and no water surrounds the sensing tip. You can then overheat the engine without even knowing it.

Although not on a Pontiac, I've done this on a ford focus! Gauge read normal, never bothered checking the level As it never leaked or used coolant. Started pinking early on and by the time I got a few miles from home the engine lost performance rapidly and started to smell funny. Pulled over to find a practically empty cooling system with no warning whatsoever.

sure did.

Found this which should help me work all the pipe work out: