Need help...wiring diagram for a '88 911

[Mark Howard]

Hi guys. I'm looking for a wiring diagram for an '88 911. PP seems to only have early SC diagrams. My heater blower quit working and when I began to trace the problem, I discovered that +12V is coming down the ground wire to the blower! Thinking maybe a bad relay or some other electrical connection.

Any ideas?

Mark

[turn6]

Mark,

Do U have this page;
http://www.msroadrace.com/TechStuff/Group9%20Electrical%20911,%20930%2087-89.htm

[john walker's workshop]

juice flows power to ground. if the ground wire is not grounded, you can get a voltage reading on it. see if you are getting power to the blower in the engine area. the footwell fans won't work unless the engine blower is working. suspect the relay for it on the engine room panel, unless you have power to the blower.

[Argo]

I've been working on this same problem today on my 88 Targa. No juice at the fuses or blower motor with the key and center console switch on. That leaves the switch and relay as possibilities. I suspect the relay, as it seems they blow out more frequently than switches.

John Walker: Which relay is it, if you know, the small one or the large one and is there a way to check it for function (it's easier to access than the switch)? Pelican doesn't seem to stock these relays; is this because they are interchangeable with another one (AC or fresh air blower, maybe)?

Turn6: Thanks for the wiring diagrams - I've been looking all over for those!

My intermittent wiper and intensive cleaning switches are also dead (the steering column wiper/washer stalk switch wets down the passenger side; the driver side is likely just a clog in the fluid line or nozzle) Anyone have any tips on where to start diagnosing those?

I swear, this BB is better than the Porsche shop manual - I've found useful threads on every single question/problem I've had!

Argo
88 Targa

[expat]

I can scan a copy from the Bentley Manual tommorrow if you still need it.
Mark

[Mark Howard]

You guys are the best! Thanks for your input Turn6 and John. Looks like I have a weekend project.



------------------
Mark Howard
'97 993 Carrera
'88 Carrera
'62 356/B (going into the hanger)
'75 914 1.8 (resto in final stages)

[john walker's workshop]

the relay is the smaller one. #91161815300. the other one is rear defroster. check power to term 12 from the front fusebox.(black/red wire). check power at terms 7 and 8, from the center fuse on the engine room panel. (red/white wires). check power on term 3, from the bottom fuse, (red/black wire). one of these is "key on" power as i recall. for power out of the relay to the engine blower, check terms 5 and 6. (yellow/red wires). term 2 is grounded.

[Britwrench]

Argo,

It doesn't sound like the electrical part of windshield washer system is faulty; if the jets spray even a little bit then the pumps are working. The usual problem is the non-return valves are stuck. you need two 'L' shaped and two 'T' shaped valves. Replace them, clean the lines and jets, refill the washer and intensive wash tank and it should all work again. If it hasn't worked for some while you might find the washer tank is full of slime; remove and thoroughly clean and refit.

'L' valve part number; 477 955 481
'T' valve part number; 914 628 433 00
clip part number;(10 req) N 100 020 1

[john walker's workshop]

britwretch, you da man.

[Argo]

You both are. You should send me a bill for that kind of help.

Argo
88 Targa

[john walker's workshop]

what's your address?

[Argo]

Latitude 43 31' 39" N
Longitude 70 08' 34" W

I'll pay it as soon as it arrives.

(2 minutes to send the bill? That's almost as fast as my insurance company!)

Argo
88 Targa