MAGNUM SERVICES
Intelligence Guided By Experience
Bought a 94 GMC Jimmy S15 and the Blower Motor only works on Low/Medium, not High. ALL Fuses good as is the Fusible Link, NEW Resistor/Relay/Motor but NOT Switch, any ideas?
-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
A/C Heater Blower Motor
- Thread starter MAGNUM SERVICES
- Start date
- Staff
- #2
If it doesn't work on high but all others, then all it could be is the high blower relay or the switch. For high fan speed all there is is the switch or the relay depending on how it's wired.
MAGNUM SERVICES
Intelligence Guided By Experience
Relay was replaced so that leaves the switch, Thank You for your reply!
MAGNUM SERVICES
Intelligence Guided By Experience
Switch replaced, still no High Blower
MAGNUM SERVICES
Intelligence Guided By Experience
Any ideas from anybody?
Good parts don't mean they were the first new parts out of the box you tried...
Blower motor spins at any other speed - it's good. High current draw from a bad motor can damage the skimpy GM wires and connectors. (Even a good motor can in some cases.) Possible bad ground that fails at high speed current. Test blower motor to good ground for voltage. Take action on anything over 0.5v.
Start at the high speed relay - does it have 12v power and a 12v signal to the relay coil? Good ground? Jump the relay and see if the motor runs.
No 12v coil signal at high speed - wiring back to the switch and test switch.
Fusible links are good because you tested for voltage right? They can break from age with no burn marks.
Blower motor spins at any other speed - it's good. High current draw from a bad motor can damage the skimpy GM wires and connectors. (Even a good motor can in some cases.) Possible bad ground that fails at high speed current. Test blower motor to good ground for voltage. Take action on anything over 0.5v.
Start at the high speed relay - does it have 12v power and a 12v signal to the relay coil? Good ground? Jump the relay and see if the motor runs.
No 12v coil signal at high speed - wiring back to the switch and test switch.
Fusible links are good because you tested for voltage right? They can break from age with no burn marks.
MAGNUM SERVICES
Intelligence Guided By Experience
I will check my fusible links again, Thank You for the reply
jrsavoie
Recruit
I've seen bad resistors. Maybe somebody knows how to test that. I don't know if the resistor is used on high. For temp, you could run an additional fused wire to the fan.
I always add a ground from the blower to the dash bolt inches away.
I always add a ground from the blower to the dash bolt inches away.
MAGNUM SERVICES
Intelligence Guided By Experience
I found it, someone tried to heat shrink two wires together instead of using a connector, it's working great now! THANK YOU to ALL who replied!