bigeo
11-15-2025, 01:38 AM
Sometime in the recent past the front blower fan on my 87 van started to work intermittently. If I remember correctly, it would work at the high speed setting. I figured it was a bad resister block and planned to replace it, although I had done this before a few years ago. Now it has stopped working at any speed so it seemed likely that it was the motor and the intermittent problem was just the brushes gradually giving out entirely. Before ordering a new fan motor, I checked for power at the plug and discovered there wasn't any. I pulled the resistor pack which looks fine and checked for power there and, again, no juice. I used a paper clip on the breaker with no effect. Pulled the breaker out and checked for continuity: yes.
I then liberated the heater controls from the dash and tested for power at the switch. It took me a few tries because I wasn't sure which contacts were what, but I was able to detect battery voltage between contacts. To check if the issue was the slider switch, I tried bridging between contacts with a piece of wire. It didn't make the fan run, but it did result in a clicking noise under the dash in the vicinity of the fan breaker.
To make sure that I had a working fan motor, I tried powering it directly from the cig lighter with no response. I checked for voltage at the lighter plug and there was none. I then used another 12v battery to apply power and the fan worked.
Another issue I have been having for months is the aftemarket radio turning off and on without prompting.P
I'm guessing that there is an intermittent power/ground (connection) issue behind all of this. I have checked fuses, inspected the wiring I can see, pulled the fuse block out far enough to get a mirror behind to check if anything looks bad and have found nothing. I checked again for power at the fan control switch and couldn't detect any.
All the other electrical stuff works and the cig. lighter was working recently (it charged my cell phone)
I'm not sure where to look next. Any ideas?
I then liberated the heater controls from the dash and tested for power at the switch. It took me a few tries because I wasn't sure which contacts were what, but I was able to detect battery voltage between contacts. To check if the issue was the slider switch, I tried bridging between contacts with a piece of wire. It didn't make the fan run, but it did result in a clicking noise under the dash in the vicinity of the fan breaker.
To make sure that I had a working fan motor, I tried powering it directly from the cig lighter with no response. I checked for voltage at the lighter plug and there was none. I then used another 12v battery to apply power and the fan worked.
Another issue I have been having for months is the aftemarket radio turning off and on without prompting.P
I'm guessing that there is an intermittent power/ground (connection) issue behind all of this. I have checked fuses, inspected the wiring I can see, pulled the fuse block out far enough to get a mirror behind to check if anything looks bad and have found nothing. I checked again for power at the fan control switch and couldn't detect any.
All the other electrical stuff works and the cig. lighter was working recently (it charged my cell phone)
I'm not sure where to look next. Any ideas?