Hot water valve

[davidc89]

I am replacing the hot water valve, as the bypass that the previous owner put in failed, and I can't seem to find where the vacuum hose is that goes to it. Any suggestions?

Also in troubleshooting why my cooling fans did not come on at idle, I notice the Fan Fail relay was missing and it wasn't bypassed... Maybe that could be the issue?

Thanks,

David 2347

[Chris 16409]

If your fan fail socket is empty you will never have the cooling fans come on. You need to install a jumper or buy one of Dave M's solid state fan fail relays.

[AugustneverEnds]

The vacuum hose comes from the driver's side pontoon, up in the corner, small diameter yellowish color. At least on mine, I am assuming all Ds are the same in this department.

Look at the upper left hand side of this pic: https://www.google.com/search?q=delorean+engine+bay&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjKraKxndrTAhVBbiYKHcH_DEkQ_AUIBigB&biw=1366&bih=634#imgrc=LVqABBSMQkH6kM:&spf=198

Bypass the fan fail if you are in a hurry, fused jumper wire if you prefer or Bitsyncmaster's solid state if you like.

[davidc89]

I bypassed the relay as stated and still didn't work. I jumped the otterstat and the fans would run. So I'm not sure if I still have air in the system or a bad otterstat.

[Rich]

I am replacing the hot water valve, as the bypass that the previous owner put in failed, and I can't seem to find where the vacuum hose is that goes to it.

The OE hose is thin, stiff black plastic tubing, not a flex hose. It feeds out of the forward left wall of the engine bay (from driver side pontoon as mentioned) through a rubber grommet. On the end of it a short black coupling (rubber hose) connects it to the heater valve port.

[hippieman9]

should you be able to depress the lever on the hot water valve by hand? I am trying to see if mine is bad. Doesn't move no matter what setting the switch is on at the console.

[PJ Grady Inc.]

should you be able to depress the lever on the hot water valve by hand? I am trying to see if mine is bad. Doesn't move no matter what setting the switch is on at the console.

Yes. Sounds like yours is seized.
Rob

[hippieman9]

Yes. Sounds like yours is seized.
Rob

Ok, I can depress it by hand, but doesn't seem to work with the mode switch.

[Bitsyncmaster]

Ok, I can depress it by hand, but doesn't seem to work with the mode switch.

You can just pull the vacuum hose and connect another hose that has vacuum to test it. Or just check that vacuum hose for vacuum when the AC is set to MAX

[hippieman9]

You can just pull the vacuum hose and connect another hose that has vacuum to test it. Or just check that vacuum hose for vacuum when the AC is set to MAX

So I have a vacuum tester, and I pulled vacuum on the hot water valve and it works, I traced the vacuum line to the mode switch to find that it was not plugged in. Also found that the flap under the passenger footwell wasn't working and that these work on the same vacuum line, Well the rubber line was unhooked from the Tee. I plugged it back in and the foot well flap moves slightly, and the hot water valve still doesn't move.... Looks like I must keep looking. Is there a diagram that shows what line goes where on the back of the mode switch?

[JETS 81 DMC]

Here is the mode switch diagram thanks to Ron :

http://dmctalk.org/showthread.php?8068-Mode-Switch-Vacuum-Connections-Functions

[hippieman9]

Here is the mode switch diagram thanks to Ron :

http://dmctalk.org/showthread.php?8068-Mode-Switch-Vacuum-Connections-Functions

Cool, I just found that in one of my manuals. Had a couple lines mixed up from some previous work when the PO owned it. Got the recirculating flap to open slightly but the hot water valve is still not moving. Going to trace that line from the console to the valve and see if I have a cracked line or something.
It works if I put a vacuum right on it. So the valve should be alright.

[hippieman9]

Ok anyone know where the A/C vacuum tank is located? Part number 100764

[FABombjoy]

Inside the LH pontoon. Access by removing the vapor canister plate. You can see two nyloc nuts holding the vacuum tank it to the engine compartment wall.

[hippieman9]

Inside the LH pontoon. Access by removing the vapor canister plate. You can see two nyloc nuts holding the vacuum tank it to the engine compartment wall.


Oh ok, so in front of the charcoal canister then?

[FABombjoy]

Oh ok, so in front of the charcoal canister then?
Yep! Remove the canister and reach inside toward the front of the car. It's pretty big - you can't miss it.

Well, it's not as big as those repainted Folger's cans that Ford used to use, but it's still pretty big.

[hippieman9]

Yep! Remove the canister and reach inside toward the front of the car. It's pretty big - you can't miss it.

Well, it's not as big as those repainted Folger's cans that Ford used to use, but it's still pretty big.

LOL, OK cool thank you. I will check that.

[CriticalB]

Cool, I just found that in one of my manuals. Had a couple lines mixed up from some previous work when the PO owned it. Got the recirculating flap to open slightly but the hot water valve is still not moving. Going to trace that line from the console to the valve and see if I have a cracked line or something.
It works if I put a vacuum right on it. So the valve should be alright.

I just got my vacuum lines sorted earlier this week. To make sure the mode switch diaphragm was working, I took out the radio and unplugged the rubber fitting from the back of the mode switch. I hooked my vacuum tester to port 1 on the mode switch and felt by hand to see which ports were pulling vacuum for each mode setting. Using the mode switch diagram from the workshop manual, I logged what each port did on each setting and was able to rule out an issue with the diaphragm.

Next I connected the tester to each port on the rubber fitting to make sure each individual hose was actuating the correct flaps. This is where I determined a PO had mixed up some of the hoses. My recirc vent and heater valve were only opening on defrost, and remaining closed on Max. Swapping those solved my problem.

Since the recirc vent and heater valve are tee-d off the same port behind the console and they seem to be getting weak vacuum, you might want to hook up your tester to each line individually from the tee. That way you can confirm which branch has a potential leak. If it's the recirc line, that might save you the trouble of digging through the center console and pontoon.

[hippieman9]

I just got my vacuum lines sorted earlier this week. To make sure the mode switch diaphragm was working, I took out the radio and unplugged the rubber fitting from the back of the mode switch. I hooked my vacuum tester to port 1 on the mode switch and felt by hand to see which ports were pulling vacuum for each mode setting. Using the mode switch diagram from the workshop manual, I logged what each port did on each setting and was able to rule out an issue with the diaphragm.

Next I connected the tester to each port on the rubber fitting to make sure each individual hose was actuating the correct flaps. This is where I determined a PO had mixed up some of the hoses. My recirc vent and heater valve were only opening on defrost, and remaining closed on Max. Swapping those solved my problem.

Since the recirc vent and heater valve are tee-d off the same port behind the console and they seem to be getting weak vacuum, you might want to hook up your tester to each line individually from the tee. That way you can confirm which branch has a potential leak. If it's the recirc line, that might save you the trouble of digging through the center console and pontoon.

Yes Good Idea, I was thinking of pulling vacuum before the Tee to first see if they both work, then do each one individually to see if maybe I have a bad line. The Recirc flap only seems to open slightly when set to Max now since I swapped the 2 hoses that were wrong. Mine had Position 1 and 3 reversed . I want to check the canister in the pontoon as well, because The hot water valve doesn't move at all and I would like to make sure that is hooked up correctly, I am just wondering if maybe something is wrong there causing a low vacuum? in turn not closing the hot water valve.

[SS Spoiler]

Check to see if the rubber plug on the vac chamber
is crumbled and cracked...mine was

[Bitsyncmaster]

Check to see if the rubber plug on the vac chamber
is crumbled and cracked...mine was

I think you mean the rubber plug on the vapor canister.

[SS Spoiler]

You're right, it's been a while since I did that....15 years?

[hippieman9]

I found my vapor canister was missing the rubber plug altogether. I put on on it. Just put the console all back together last night. I pulled vacuum from the rubber plug on the back of the mode switch and the hot water valve and the recirc flap open or closed.
I checked the vacuum canister and everything looks to be fine hooked up to that.
So now I am off to start it up and make sure it functions correctly.

[hippieman9]

I ended up replacing the vacuum line from the mode switch to the hot water valve and it all functions perfect now. recirc flap opens all the way up and the Hot Water valve closes. So was a combination of vacuum lines in the incorrect place at the mode switch and a bad vacuum line to the hot water valve. I bet the A/C will get cold now!