Heater Trials and Tribulations, Chapter Two
 

The saga continues. I now suspect engine compartment heater relay (Thanks Andrew/aj88cab and Fintstone – you guys sure know your stuff). Problem started with footwell blowers running all the time. Engine blower worked fine. Removed fuses from footwell blowers and relied on engine blower alone until I had time to trace problem and try Andrew’s strategy.

Used the engine blower alone (heat was not bad, only a minor problem defrosting during rainy periods – this is a daily driver) for two weeks. Then engine blower stopped working before I could test Andrew’s suggestion (heating still not bad – I now understand the heater blower delete threads). However, it’s not ok to have stuff that doesn’t work on the car.

As you can see from the posts above, I’m not an electrical genius. This is what I just tested though: (With ignition and lever/switches on.) Starting at the engine blower, I checked for power with test light – none. Power is OK through fuses in engine compartment and power OK to female receptacles #3, 7, & 8 on relay connector. With relay out and no power source, I found continuity between pins 5 and 6, and between 7 and 8. Cleaned pins and reinstalled relay. Still no success with engine blower. Reinstalled fuse in footwell blower and it no longer works under any conditions. Can I assume this is enough evidence to convict engine relay? Should I punish the relay with a screwdriver handle? Should I buy a used one and see what happens? Should I find 250 bones for a new one?:confused:

Sounds like the engine compartment relay is history. If you're real adventuresome you could open it up and see if there is anything obvious wrong, but it sounds like is beyond repair. If you know someone with a P-car that's willing you could switch the relay to make sure one last time.

New or used relay? Depends on what ($) you can find the used one for. I don't know if this relay goes bad in alot of cars but if not a used one may be a safe option.

Good luck.

Hi
Sorry I haven't been folllowing this thread..been travelling. Could well be the engine compartment relay. Do you have ground at pin 2 and 12v at pins 11 and 12 of the engine compartment relay? What did you have on pins 2 and 10?

OK, this is a stretch but I can sense the despiration in your posts.

Just a thought I had on my lunch break.

Check all the items "flintstone" said above. If they are all OK it is pretty much a given the problem is in the relay. So if you're up for it, try this ......

On top of the engine, up behind the throttle body, on the drivers side of the oil breather is a temp switch that is supposed to run the blower fan to cool a too hot engine after you shut it off (the wire is a "spiral" looking cable). If you can reach it pull this connector off and with the ignition OFF ground the connector (this goes to pin #10). The blower should come on. If it doesn't, the engine compartment relay is toast. If the blower does go on, go in the car and see if the footwell blowers are running. If the footwell blowers are running there might be a bad diode in the engine compartment relay. If they are not running there might be a bad pin connection in the relay (7,8,9 likely). If you're handy with a soldering iron you might be able to fix it. Lots of "maybes" and "mights", like I said, it's a stretch! Its the obsesive kind of thing I'd do just for my own edification.

On the other hand, just replace the relay and so you can spend the weekend driving instead of repairing:)

As always good luck!