944 85' 944 Sometimes won't start - Fresh Air Blower fan hot!

[Foolsbry]

Hey everyone!

I recently discovered that my 1985 944 isn't exactly water tight, had some rain leak into the passenger side footwell. I could see there was a bit of water on the wiring, and a little bit on top of the DME box. The night that it happened it started fine, but a few nights later I was driving home and died at some traffic lights, car would turn but no tach bounce. I try and start the car the next day and it starts up and runs as normal, take it for a spin and everything seems fine.

Then today I go to start it again and it's no go once more. Cranks but no tach bounce. I go out and buy a multimeter to test the DME harness according to this video;

This is later on in the day and I think, "might as well see if it wants to start now" and of course, it does easily. I still proceeded to remove the DME harness and give it a test, all the tests seemed to come up positive, so I'm a little stumped as to what the issue could be for it to start sometimes, but not always. I was inspecting the Fresh Air Blower afterwards as this is where the water had originally leaked in due to the plastic shroud not sitting flush against the body - another issue I have to fix.

I touched the shroud and noticed it was really quite hot, considering the fan hadn't been running at all. I was cranking the car for maybe 30 seconds in total during the test, keys were in the ignition for the last part of the test which required turning the car over to check the voltage. It just strikes me as odd that the Air Blower could be getting so hot from doing nothing, and I'm thinking there might be a wiring issue with it, which would hopefully be linked to causing it not to start as well.

Any insight would be greatly appreciated!

Thanks,

Garth

 

EDIT - Out of curiosity, I took the keys out of the ignition and left it a bit, the Air Blower went cold, then I put them back in and left it for about 10 mins and the thing had already heated back up, that was with no cranking, just the keys simply being in the ignition. Weird!

[Zelrik911]

Do you have a car alarm? Just a suggestion!

On a non- P car, I had a simmilar thing with the alarm wiring to the key starter being dodgy. Many years ago though.

[Foolsbry]

Thanks for the suggestion! I don't have a car alarm in mine, at least I'm pretty sure I don't. It's a non-turbo model, don't even have AC. Wish that was the issue though haha

[3legs]

Im no electrician but the air box getting hot could be a bad earth or a short attached to your ignition switch and when the key is inserted it then completes a circuit. Also the reason the car starts then dies could be from bad connections due to condensation. 

I would just pull all fuses, plugs etc and give then a clean and light spray of WD40 and see what happens.

As I said I'm not an electrician but some similar problems on my bikes were fixed as per above.

[Foolsbry]

I did buy some new fuses the other day, so I might give that a go, thanks! I tried to open the DME box to see how much if any liquid got into it, but for some reason on each side there's one screw lock-tighted into position that I can't get off. So when you say bad earth, you're meaning it's possible the ground wire isn't entirely contacting with what it's supposed to be grounded to?

[3legs]

Yes. Check all earths especially any that relate to the blower. Test the blower motor as well. Also make sure the ignition switch housing isn't live. Unlikely as that would blow a fuse the moment you stuck the key in but check anyway. Again I'm no electrician. Probably clutching at straws.

[brian in buddina]

I second on checking the earths. Any electrical issues, according to Clarks & others, on a 944 usually say to check & clean all the grounds. There is a diagram somewhere showing there locations.