My car has no heat
- Thread starter 19supra90
- Start date
Check your heater valve.
Up on the firewall by the Evap canister with 2 heater hoses going to it. Also has one vacuum line going to the top of it.
Up on the firewall by the Evap canister with 2 heater hoses going to it. Also has one vacuum line going to the top of it.
DegreE;986385 said:
yep. not a cheap part to replace either IIRC.
also i THINK their was another year car that you could use that would work and was cheaper...
Calling Jeff Lange?
If it is the valve, a quick temporary fix would be to take off the vacuum line from the diaphragm on top of the heater control valve, and replace it with the other vacuum line that is plugged into the electrical part of the valve.
Does the valve fail often? My car sat for a long time (years) if this makes a difference. Would a blockage or partial blockage cause an intermittent squeal similar to a belt if it was hung up? I'm trying to diagnose my car based on the symptoms, one of which like the thread starter is no heat.
Thanks.
Thanks.
I am going through the same problem.....I found that if you take the two vacuum hoses and connect them you will get heat but as soon as you plug it back into the valve it goes away.......so yeah as a temporary fix just do what dunckel suggested^^^^^
If you do wind up buying one, one off of a certain mercedes model is cheaper than buying one from toyota:aigo:.... go figure. Anyways, does anyone know the model?
I have the Mercedes VSV in there for the heater valve, but I did it a long time ago, so I don't remember the part number. It should still be in the tech tips section on the supras.com website though.
I think this link has relevant info:
http://www.rclambert.com/supra/vsv.htm
Full text:
MK3: Hot water valve vacuum solenoid valve (VSV) replacement
If your heater fan runs normally but there is no heat, the vacuum solenoid valve (VSV) probably needs to be replaced. With two exceptions, the VSV is energized anytime the engine is running which allows vacuum to be applied to the hot water valve actuator which in turn opens the heater core hot water valve. If the VSV is burned out, the water valve won't open producing the no heat symptom.
A. Determine if the VSV is malfunctioning
1. Find the valve that controls the flow of hot water to the heater core. It's located in the engine compartment on the passenger side firewall about a foot inboard of the right hood strut behind the black cylindrical charcoal canister (Picture 1). There is a vacuum hose running from the top of the valve actuator to the vacuum solenoid valve (VSV). There is another short (2") rubber vacuum hose that connects the solenoid to a vacuum line that runs along the firewall behind the engine. These two lines are joined by a male/male connector
2. Start the car and put the temperature control system in the AUTO mode and adjust it to it's lowest setting (65 deg F). The fan should be on high and the control rod coming out of the bottom of the water valve actuator should be extended (down) which closes the water valve (Picture 2)
3. With the car running, the AC off, the temperature control system in the AUTO mode, adjust the temperature to anything but it's lowest setting (66 deg F or higher). The control rod coming out of the bottom of the water valve actuator should now be retracted (up) which allows water flow to the heater core (Picture 3)
4. If the control rod doesn't move, unplug the VSV electrical connector and see if there is 12 volts at the female side of the connector (coming from the wiring harness). If there is 12 volts here the VSV is most likely burned out. Double check with an ohmmeter to make sure it's the solenoid that's burned out and not just a bad connection. Measure the resistance between the contacts in the male side of the connector (coming from the VSV). A good valve should have a resistance of around 25 ohms. At least this is the resistance of the Mercedes Benz replacement unit - Toyota's unit might be a little more or less (the failed Toyota unit I took out of my car measured 852 ohms)
5. If there is no voltage at the female side of the connector, stop here - the problem may be with the A/C control panel assembly
6. If the control rod moves up and down the VSV is OK. Stop here - the problem is with some other part of the system
B. How to bypass the VSV to get heat temporarily while waiting for replacement
1. This will cause the heater core water valve to open anytime the engine is running
2. Unplug the short solenoid vacuum hose from the male/male connector
3. Unplug the valve actuator vacuum hose from the solenoid valve and plug it onto the male/male connector the short hose was disconnected from (Picture 4)
4. If the car is running and the rest of the system is working correctly, as the actuator line is plugged onto the male/male connector vacuum will pull the control rod up and open the water valve
C. Replacing the VSV
1. Buy entire vacuum solenoid - vacuum operator - water valve from Toyota for $150 or......
2. Use the great tip contributed by Dana Franklin who discovered that Mercedes Benz sells just the solenoid valve alone for a lot less money. Buy the parts for the vacuum pump air valve switch for a 1985 500 SEL from your local Mercedes Benz (MB) dealer (part numbers were current as of October 1998. Costs were from Maplewood Imports in Minnesota, (651) 766-2333 www.maplewoodimports.com):
1. Qty 1 Solenoid Valve - Mercedes Benz #001-540-86-97 $24.00 each
2. Qty 1 Cable Connector - Mercedes Benz #008-545-11-28 $0.50 each
3. Qty 1 Cable Connector - Mercedes Benz #008-545-08-28 $0.70 each
4. Qty 2 Contact Bushing - Mercedes Benz #001-545-44-26 $0.70 each
3. Unplug the VSV electrical connector
4. Remove the two vacuum lines from the VSV
5. Take the VSV from the car by removing the one screw holding the it to the valve assembly bracket
6. Remove the rubber boot that fits around the wires as they enter the VSV and slide it up the wires towards the connector (Picture 5)
7. Remove the air filter and rubber bushing from the old VSV to reuse on the new one (this filters the vent air that is allowed back into the actuator when the VSV in de-energized) (Picture 5)
8. Cut the wires off the existing VSV as close to the old unit as possible so that they can be reused on the new MB unit
9. Strip and solder each of the old connector wires to a new MB contact bushing
10. Insert the two contact bushings into the MB #008-545-11-28 cable connector making sure that neither the wires or any solder shorts the two leads. It doesn't make any difference which bushing goes into which hole since a solenoid is not polarity sensitive (Picture 6)
11. Apply silicone sealant or RTV in the cavity around the two bushings and wires especially around the point where the wires exit the connector. This is just to provide some strain relief to the wires since they are too small to be effectively held in place by the connector
12. Before the silicone sets up snap the top half of the cable connector (MB#008-545-08-28) onto the 008-545-11-28 cable connector and let the silicone cure for 24 hours
13. Push the MB cable connector onto the new VSV until it locks in place (Picture 7)
14. The MB solenoid has a numbered diagram on its side. Install the filter and small rubber bushing from the old VSV onto the new MB unit on port #1 (Picture 7)
15. Reinstall the old short vacuum hose on MB port #2. If using new vacuum lines, apply a little silicone grease to the barbed ports and be careful because they're plastic (Picture 8)
16. Install the new MB VSV with a #6 bolt, fender washer, locknut, and nut using the hole in the original valve bracket that held the old VSV (Picture 8)
17. Reconnect the short vacuum hose on port #2 to the vacuum line from the engine. Be sure to position the line so as not to rub on the water valve control rod and linkage (Picture 9)
18. Plug the vacuum line from the hot water valve actuator onto MB port #3. If you mount the new unit as shown in the picture a new piece of 3 mm vacuum hose will be needed because the old one won't reach (Picture 8)
19. Reconnect electrical plug
Contributed by:
Dick Lambert 89T
rlambert@rclambert.com
11/21/98
http://www.rclambert.com/supra/vsv.htm
Full text:
MK3: Hot water valve vacuum solenoid valve (VSV) replacement
If your heater fan runs normally but there is no heat, the vacuum solenoid valve (VSV) probably needs to be replaced. With two exceptions, the VSV is energized anytime the engine is running which allows vacuum to be applied to the hot water valve actuator which in turn opens the heater core hot water valve. If the VSV is burned out, the water valve won't open producing the no heat symptom.
A. Determine if the VSV is malfunctioning
1. Find the valve that controls the flow of hot water to the heater core. It's located in the engine compartment on the passenger side firewall about a foot inboard of the right hood strut behind the black cylindrical charcoal canister (Picture 1). There is a vacuum hose running from the top of the valve actuator to the vacuum solenoid valve (VSV). There is another short (2") rubber vacuum hose that connects the solenoid to a vacuum line that runs along the firewall behind the engine. These two lines are joined by a male/male connector
2. Start the car and put the temperature control system in the AUTO mode and adjust it to it's lowest setting (65 deg F). The fan should be on high and the control rod coming out of the bottom of the water valve actuator should be extended (down) which closes the water valve (Picture 2)
3. With the car running, the AC off, the temperature control system in the AUTO mode, adjust the temperature to anything but it's lowest setting (66 deg F or higher). The control rod coming out of the bottom of the water valve actuator should now be retracted (up) which allows water flow to the heater core (Picture 3)
4. If the control rod doesn't move, unplug the VSV electrical connector and see if there is 12 volts at the female side of the connector (coming from the wiring harness). If there is 12 volts here the VSV is most likely burned out. Double check with an ohmmeter to make sure it's the solenoid that's burned out and not just a bad connection. Measure the resistance between the contacts in the male side of the connector (coming from the VSV). A good valve should have a resistance of around 25 ohms. At least this is the resistance of the Mercedes Benz replacement unit - Toyota's unit might be a little more or less (the failed Toyota unit I took out of my car measured 852 ohms)
5. If there is no voltage at the female side of the connector, stop here - the problem may be with the A/C control panel assembly
6. If the control rod moves up and down the VSV is OK. Stop here - the problem is with some other part of the system
B. How to bypass the VSV to get heat temporarily while waiting for replacement
1. This will cause the heater core water valve to open anytime the engine is running
2. Unplug the short solenoid vacuum hose from the male/male connector
3. Unplug the valve actuator vacuum hose from the solenoid valve and plug it onto the male/male connector the short hose was disconnected from (Picture 4)
4. If the car is running and the rest of the system is working correctly, as the actuator line is plugged onto the male/male connector vacuum will pull the control rod up and open the water valve
C. Replacing the VSV
1. Buy entire vacuum solenoid - vacuum operator - water valve from Toyota for $150 or......
2. Use the great tip contributed by Dana Franklin who discovered that Mercedes Benz sells just the solenoid valve alone for a lot less money. Buy the parts for the vacuum pump air valve switch for a 1985 500 SEL from your local Mercedes Benz (MB) dealer (part numbers were current as of October 1998. Costs were from Maplewood Imports in Minnesota, (651) 766-2333 www.maplewoodimports.com):
1. Qty 1 Solenoid Valve - Mercedes Benz #001-540-86-97 $24.00 each
2. Qty 1 Cable Connector - Mercedes Benz #008-545-11-28 $0.50 each
3. Qty 1 Cable Connector - Mercedes Benz #008-545-08-28 $0.70 each
4. Qty 2 Contact Bushing - Mercedes Benz #001-545-44-26 $0.70 each
3. Unplug the VSV electrical connector
4. Remove the two vacuum lines from the VSV
5. Take the VSV from the car by removing the one screw holding the it to the valve assembly bracket
6. Remove the rubber boot that fits around the wires as they enter the VSV and slide it up the wires towards the connector (Picture 5)
7. Remove the air filter and rubber bushing from the old VSV to reuse on the new one (this filters the vent air that is allowed back into the actuator when the VSV in de-energized) (Picture 5)
8. Cut the wires off the existing VSV as close to the old unit as possible so that they can be reused on the new MB unit
9. Strip and solder each of the old connector wires to a new MB contact bushing
10. Insert the two contact bushings into the MB #008-545-11-28 cable connector making sure that neither the wires or any solder shorts the two leads. It doesn't make any difference which bushing goes into which hole since a solenoid is not polarity sensitive (Picture 6)
11. Apply silicone sealant or RTV in the cavity around the two bushings and wires especially around the point where the wires exit the connector. This is just to provide some strain relief to the wires since they are too small to be effectively held in place by the connector
12. Before the silicone sets up snap the top half of the cable connector (MB#008-545-08-28) onto the 008-545-11-28 cable connector and let the silicone cure for 24 hours
13. Push the MB cable connector onto the new VSV until it locks in place (Picture 7)
14. The MB solenoid has a numbered diagram on its side. Install the filter and small rubber bushing from the old VSV onto the new MB unit on port #1 (Picture 7)
15. Reinstall the old short vacuum hose on MB port #2. If using new vacuum lines, apply a little silicone grease to the barbed ports and be careful because they're plastic (Picture 8)
16. Install the new MB VSV with a #6 bolt, fender washer, locknut, and nut using the hole in the original valve bracket that held the old VSV (Picture 8)
17. Reconnect the short vacuum hose on port #2 to the vacuum line from the engine. Be sure to position the line so as not to rub on the water valve control rod and linkage (Picture 9)
18. Plug the vacuum line from the hot water valve actuator onto MB port #3. If you mount the new unit as shown in the picture a new piece of 3 mm vacuum hose will be needed because the old one won't reach (Picture 8)
19. Reconnect electrical plug
Contributed by:
Dick Lambert 89T
rlambert@rclambert.com
11/21/98
