RE: cold start problem

[Landseer]

Dealer was where I bought the last one.

Can't Roger order it?

And its not an "uncommon" problem. These sensors are aging out.

[georges 928S]

Hi Guys,i got my new thermo time switch, but i was checking to see if there is power
coming to thermo switch plug, i only got ground with test light and nothing on the other
wire with the ignition on. is it suppose to be that or do i have problem with power not coming to the thermo from plug connector. Thanks. Ed.

[vandenham]

The wiring diagram I have shows that the power only comes on when the starter is operating.

[georges 928S]

Guess what guys, i just put a brand new (thermo time switch) and still no go, so it must be something else. what should i do next, need help. Ed.

[neil30076]

Just to be sure, we are talking about the thermo time switch, mounted horizontally on the water bridge under the front pressure regulator.

OK, so lets do some more testing-
Unplug the thermoswitch and put a voltmeter ( NOT a test lamp) from W in the plug side to ground.
try to start, you should see 12 volts when the starter is turning. Do You?
Now move the voltmeter to the G pin in the plug and repeat, Do you see 12 volts ( or close to)
If you do not, your Start valve is either disconnected or bad.
If the test is good:
You can force the cold start valve to open by removing the plug from the thermoswitch, and putting a ground wire ( carefully)from the G terminal to ground and retry.
Report back what you find.

[georges 928S]

Originally Posted by neil30076

Just to be sure, we are talking about the thermo time switch, mounted horizontally on the water bridge under the front pressure regulator.

OK, so lets do some more testing-
Unplug the thermoswitch and put a voltmeter ( NOT a test lamp) from W in the plug side to ground.
try to start, you should see 12 volts when the starter is turning. Do You?
Now move the voltmeter to the G pin in the plug and repeat, Do you see 12 volts ( or close to)
If you do not, your Start valve is either disconnected or bad.
If the test is good:
You can force the cold start valve to open by removing the plug from the thermoswitch, and putting a ground wire ( carefully)from the G terminal to ground and retry.
Report back what you find.

Thanks Neil, i will do that tomorrow and get back to you. Ed.

[Landseer]

Sorry Ed.

Will buy it from you if you want.

Let's let Neil run with it, he has proven excellent diagnostics / I'm generally just working a checklist.

[georges 928S]

Originally Posted by Landseer

Sorry Ed.

Will buy it from you if you want.

Let's let Neil run with it, he has proven excellent diagnostics / I'm generally just working a checklist.

OH,dont worry landser, we all do the best we can to help, anyways the old one looked
like a charcoil. Thanks Ed.

[neil30076]

ED, PM me a phone number if you would like to talk after you run the tests, might be a lot easier than messages here.....

[georges 928S]

Good morning Neil, i will start on this morning and let you know. any way my
cell # is 702-882-7842 you can call me and leave a message , so i can save your number to call later. Thanks for all your help. Ed.

[neil30076]

Originally Posted by Landseer

Sorry Ed.

Will buy it from you if you want.

Let's let Neil run with it, he has proven excellent diagnostics / I'm generally just working a checklist.

Thanks for the compliment, Chris - unfortunately I have a lot of spare time to look over wiring diagrams and do this

- keep on saving our cars!
Regards
Neil

[georges 928S]

Hi Neil, i pulled the thermo switch plug out and checked the volts from G to ground
and from W to ground and both readings were at 8.75 and 9.25 volts, they never reached 12 v so iam going to wait for your answer. call me at 702-882-7842 or give
me your number and i will call you. Thanks ED.

[neil30076]

Originally Posted by georges 928S

Hi Neil, i pulled the thermo switch plug out and checked the volts from G to ground
and from W to ground and both readings were at 8.75 and 9.25 volts, they never reached 12 v so iam going to wait for your answer. call me at 702-882-7842 or give
me your number and i will call you. Thanks ED.

Ed, voltage sounds way low - to make sure i am on exactly the right wiring diagram, please confirm the year of your car, and is it a euro?
I'll be able to call you later today ( Sunday)

[georges 928S]

Hi Neil, its an 82 US model, i will be home at 3.00 pm. Thanks Ed.

[neil30076]

Ed, i'll call you shortly. I'm concerned you are only seeing around 9 volts from W to ground. W goes back via the infamous 14 pin connect to relay XIV, and directly to battery voltage - so should be at least 12 volts. At the 14 pin, pin 14 has 2 wires, a heavy yellow going to the starter, and a lighter one ( yellow) going to the cold start switch. This must be 12volts, At the plug going into the switch, there are 2 wires on W - both yellow) , 1 on G blue/yellow that goes off to the cold start valve.. If we are in the right area, i'm beginning to think you have a 14 pin problem. Does the starter engage easily, or is it slow to pull in?

[georges 928S]

Hi Neil, sorry i didnt answer sooner, my starter engages very well . have no problem with it, i going to check the volts coming to the plug again ,just in case
didnt do it right and also check the 14 pin. goodby for now. Ed.