Hi - I have a 90 Bonneville and a 89 Olds 88 Royale - both presumably have the same wiring and circuitry, so I thought I would post to both groups and general GM group.
This car came from a family member in PA. When we got it three years ago, the fan switch only worked on "high" so we left it alone. The other day the fan totally died no matter what position the fan switch was on.
According to the wiring diagram, the blower swtich runs through a relay and a resistor for the "low" and "medium" settings, and directly from switch to fan on "high".
I pulled the fan out of the heater box, and hooked it directly to the battery - it worked fine. This left the blower switch, relay or resistor. I replaced the switch, and the motor works on "high" only. Back to where I originally was.
The parts guy at a local Pontiac dealer says that the relay is one of either two types, and I need to get the part number off of it to let him know. But his parts listing doesn't give the specific location of either the relay or the resistor.
I need to locate the AC/vent blower motor resistor and the blower relay. All the Haynes and Chilton books refer only to general locations - that the fan relay is either under the hood over the blower motor or under the dash at the fuse panel over the driver's feet or behind the glove box on the passenger side. I have looked and the blower relays are not in any of those positions.
I traced the wires from the blower switch under the dash to a wiring block back up behind the vent to the immediate right of the steering wheel, and from there is looks like it goes up to the left of the steering wheel and then I can't see it unless I pull the whole dash apart. From the blower motor, the wires go up under a red power connector and then under a couple of relays (not the blower fan ones) and then into a power block on the upper firewall on the passenger side.
I checked the fuse and relay block right behind the glove box, and there are two relays plugged in right now - but they are not the right part number - they run the fuel pump and one other item. So I presume that the relay and resistor for the fan blower motor are someplace up under the dash, but I would prefer not to tear the whole thing apart to find it.
So does anyone know the SPECIFIC location of the blower motor resistor and the relay? Please, do not tell me the general area based on your perusal of the manual - I want the specific location. That means I would prefer to hear from someone who has actually done this sort of repair before and knows exactly where the two parts are located.
Please respond via the newsgroup - thanks!