Removing Relays

[rcecale]

I'm trying to follow the procedures from Clark's Garage for troubleshooting the Cooling Fan Relay, but I can't even get started. The test involves removing the relay and doing a series of continuity checks across a few different terminals (Procedures are below in italics)

The problem I'm having is in step 1, removing the relay. The relay doesn't seem to want to come out.

Is there a trick to this, or do I just have to pull on it really hard? It's in a fairly difficult place to get a good grip on it, but I'm not sure that is my problem. Is there something specific that I'm supposed to do to make this thing come out any easier?

Testing Cooling Fan Relay (Early 944 with AC)
1. Remove the Cooling Fan Relay.

2. Take resistance readings on the relay as follows:

Terminals "A" to "B" - Reading should be infinite (i.e. open circuit)

Terminals "30" to "87" - Reading should be infinite (i.e. open circuit)

3. Connect a 12 VDC power supply across terminals "85" and "86". You should hear the relay click when you connect the power supply.

4. With the power supply connected to the relay, take resistance readings on the relay as follows:

Terminals "A" to "B" - Reading should be zero (i.e. short circuit)

Terminals "30" to "87" - Reading should be zero (i.e. short circuit)

5. If any of the resistance readings taken above are bad, the relay is bad and should be replaced.

Thanks for any replies!

Randy

[DSPTurtle]

Anything under the dash is a major pain to remove. I spent about 20 minutes wiggling my DME relay to get it loose. I don't have any tricks but will offer you moral support and you cuss and scream in pain from not being able to get a grip on it

[rcecale]

You must have been standing just outside the garage door...

Tried pulling on it, and only ended up making things worse. Here's what I've managed to get out so far...(sorry for the lousy picture quality)



I believe there may be some slot near the relay that needs a small screw driver inserted into it to release the relay...can't seem to find this.

Randy

[rcecale]

Well, if it wasn't a bad relay before I started messing with it, it's surely in need of replacement now!

Actually, it appears the circuit board is all dried out and easily crumbles. Looks a little singed too, as though it burned or something. Fortunately, I was able to get all of the pieces out. That one terminal in the pic tried to hang in there, but my needle-nose pliers made short work of that.



Randy

[DSPTurtle]

I was at the track a few weeks ago and had to pull my DME relay. That stuff down there gets really freaking hot. I guess that is part of the problem???

[Rasta Monsta]

That DME relay has the full draw of the fuel pump going through it. . .definately gets warm.

[rcecale]

Since I ended up with such lousy pics to post last night, I found this one today to reference to.



When I pulled it last night, I got the majority of the relay out, but terminal A broke away from it and remained stuck in the relay socket. The silicon part of the relay (circuit board) actually broke apart. the yellow in the pic above represents where the silicon broke away. I ended up having to use a pair of pliers to pull Terminal A from the socket.

On the main piece of silicon that came out with the majority of the relay, it is black in the area that surround where Terminal A was. Looks as though it was burned somehow.

Also, the solder on the wire that went to terminal one looks somewhat burned.

Randy

[John_AZ]

My cooling relay would not turn on the passenger fan. I swapped the relays between cars to confirm. The circuit pic on the relay pic from rcecale shows internals to be two relays. I could not see spending $40 for a new relay and like previous members have resoldered the DME and? I applied a pencil solder iron tip to the relay solder joints. I do not recommend touching the two small resistor/cap 4 solder points because you would need a heat sink.

I cleaned the contacts with cleaner. Works fine.




John_AZ
1988 924S + 1987 924S

[idontknow]

As for the stuck relays, I've had good luck using a copper anti seize lube on the terminals.

[rcecale]

Well, a new relay (read $44.00) and a few minutes of work, and I now have 2 fully functional fans. Both fans are now operating as designed and after running for 20 or 30 minutes, sitting in my garage, the hottest the car got was the second bar, straight up the middle.)

So, after all is said and done, I ended up with an upgraded passenger side fan (from 3-blade to 6-blade), and a new relay to make them all work. I also took the down time to troubleshoot a rattling noise I was hearing and found the O2 sensor to be loose. Tightened that baby up and the car is running so much better now.

Thanks to everyone's advice here and in my other thread for all their input.

PELICANS ROCK!!!

Randy

[white944cup]

Good job Randy!....we like happy endings. That's one job you never had to worry about with your old 911, but you are learning quickly about 944 ownership. Fortunately, if everything is working as designed, the cooling system will give you very few problems. It's unusual that you had two different things go bad at the same time....maybe the fan was drawing too much power as it was failing and burned up the relay in the process. I bet the old girl is happy now............and you too.........Terry

[rcecale]

Terry, I really have been nothing short of happy with this car. I'm glad I've got her ready to drive again. Ya know, if this was winter time, there probably wouldn't be an issue, it's just been so hot here the past several weeks...

As for the multiple issues, I believe the 3-blade fan is actually still a good fan. It was more of an issue of me not troubleshooting correctly. In fact, I placed the fan in the box along with the other spare parts you gave me when I bought the car, just in case!

Cheers!

Randy

[Arizona_928]

so are you gonna try to refurbish, the old relay?

[rcecale]

Originally Posted by AZ_porschekid

so are you gonna try to refurbish, the old relay?

No, but I'll sell it to you for $5.00, plus shipping...

Randy

P.S. Reading through this thread, it occurs to me I never mentioned how I actually got it out. I mentioned early-on here that I read there may be a slot for a screwdriver to be inserted to release the relay...not what I found at all.

I actually ended up using the small screwdriver to just pry the relay from the board...working slowly in an attempt to not cause any damage. Pried up each side I could access, just a bit at a time until it came out.

It became obvious that terminal A was stuck, so I worked through that and pulled it after the main part of the relay was out. A pair of long-nose needle-nose pliers was my tool of choice for terminal A.

[Lapponia]

Guys! Not only the DME relay supply current to fuel pump but also to the computer itself and all injectors. High current demand here over a tiny relay. I would EMPHASIZE the need of cleaning the two wirw contacts above the brake booster. There are so many important circuits going through them as mentioned above. Make yourself a big favor and clean them now. WD-40 followed by applying dielectric grease on all pins before pushing the connector halves together.
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Lapponia 944 na 1984

[Austin87]

Originally Posted by Lapponia

Guys! Not only the DME relay supply current to fuel pump but also to the computer itself and all injectors. High current demand here over a tiny relay. I would EMPHASIZE the need of cleaning the two wirw contacts above the brake booster. There are so many important circuits going through them as mentioned above. Make yourself a big favor and clean them now. WD-40 followed by applying dielectric grease on all pins before pushing the connector halves together.
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Lapponia 944 na 1984

Hi Lapponia;

Old post reading here. Can you expand info on where are these "two wirw contacts above the brake booster" and how to clean them ? do you have a picture or link to where and what that is ?
I'm dealing with ruling out things due to electrical and starting issues. On the DME relay needing a wiggle in order for car to run. Stop wiggling = stops running.. . maybe. Mine is an '88 924S .