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1998 V70 Cruise Control FIXED!

posted by  someone claiming to be cn on  Mon Apr 25 12:08 CST 2005 [RELATED]

Symptom: 1998 V70 Cruise would engage only one out of approx. 20 times.
Design of system: a bit complex but basically the AIR PUMP (sits below battery) powers the vacuum system for Cruise Control.

TESTING AND TROUBLESHOOTING TIPS:

1. To check AIR PUMP:
Open the Main Fusebox (engine compartment). The Air Pump Relay is the same as the Main System Relay (schematic is 85-86 and 30-87).
Jump 30 and 87 terminals, if AIR PUMP runs, this proves that the AIR PUMP is still good. But there is no warranty that the RELAY is good.
Next, swap RELAYS, then start the car, if the AIR PUMP was defective, then you will NOT be able to start the car. If car starts (it should) then BOTH RELAYS are good.

2. To check BRAKE PEDAL SWITCHES:
- Remove the COVER below the steering wheel (knee level), held by a single Torx screw in the center.
- Use a Flashlight, you will see 2 separate switches ABOVE the BRAKE PEDALS.
a. One switch for the Rear Stop Lights
b. The switch above is for CRUISE CONTROL. There is a vacuum hose attached to it. Use your index finger and move the SWITCH TIP (the part that touches the Pedal) back and forth to ensure it is not stuck.

My theory was that over thousands of times the BRAKE PEDAL was depressed, the tips of BOTH switches are slowly sworn out by friction. What happens next is the Cruise Control Brake Switch (calibrated down to 1/10th of a millimeter) now protrudes out more, causing the system to “think” that the Brake Pedal is applied, and therefore you cannot activate the Cruise Control because the Cruise Control system is designed in such a way that when the Brake Pedal is applied, the Cruise is turned off.

My simple fix was to press down on the METAL BRACKET that holds Both of these 2 switches. Press the METAL BRACKET so it goes toward the Brake Pedal a millimeter or so. The new position for the METAL BRACKET now effectively turns off both switches.
c. Sprayed some WD-40 just in case there is corrosion in the switches (from winter salt etc.)

*** Declared Victory! Cruise Control now works 100% of the time.

cn
1998 V70 62K miles





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New 1998 V70 Cruise Control FIXED!
posted by  someone claiming to be cn  on Mon Apr 25 12:08 CST 2005 >


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