I am trying to get the cruise control function working in my 88GT again.
I did the electrical tests at the cruise control module and found it failed
one of the tests. This is testing the multifunction stalk, so I replaced it
with a new one from the Fiero store. Still no cruise function. I'm thinking
of redoing the electrical tests, but cannot think the wiring would be bad
as there aren't any moving parts the wiring sees that would fray or break
them. I'm an electrical engineer, so this is not hard to do with a
multimeter.

My question is with the brake/clutch pedal switches. Can you eliminate
them as a the problem if the brake lights work and the car won't start
without depressing the clutch pedal. IE the switches are functioning
properly and the problem is somewhere down stream?

I have replaced the vacume lines with Rodney's stainless steel
vacume lines and checked to see that one of them has vacume at
idle as it should, so I think I can eliminate this as the problem.
Also, I have looked at the rest of the vacume lines and made sure they
are not brittle or have any cracks in them.

The speedometer works fine so I don't think it could be a bad signal
from that.

I've read about doing some electrical tests for the vacume solenoid
and plan on doing those. Can you get a new solenoid seperately or do you
have to buy the whole vacume can assembly?

The engineer in me doesn't like throwing money at a problem and doing
the shot gun approach. I do not have an oscilloscope at home do to some
of the electrical tests or a second person to assist to do some of the tests.
So I understand that makes it difficult. Also, I've read several of the posts
and studied the shop manual on what to look for to solve the problem.

I do have a 3.4L pushrod engine conversion, but this shouldn't have any effect
on the function that I know of.

Can anyone answer my questions or give any suggestions? Thanks in advance...

Hi, This may or may not help--but did you check to see if the cable behind your T.B. is hooked up? After alot of conversions --folks tend to forget this. You may want to see if the other end of the cable is in the correct hole in front of the diaphram. On your other question , yes I think it would be safe to assume your switches are ok , if your brake lights are working and the car starts when the clutch pedal is depressed .

If you still have easy acess to the Cruise module a few electrical tests can be done. With the key on and the cruise on you should have 12V going to the gray wire (goes thru the brake switch )and also to the dark green wire ( goes thru the clutch switch). The dark blue wire is a momentary 12V from Coast/Set and the gray/white wire is momentary 12V from accelerate/resume . The yellow wire is 12V in run

quote Originally posted by 3800superfast: ............... On your other question , yes I think it would be safe to assume your switches are ok , if your brake lights are working and the car starts when the clutch pedal is depressed .

Not true! The cruise switches for the clutch and brake are seperate from the start switch and brake light switch. If you look under the dash you should see two switches mounted on brackets at each of the pedals. On both pedals the lower of the two switches is for the cruise control. Both switches should be adjusted so that just slightly depressing either pedal will turn off the cruise. The switches are wired in series and are normally closed. Pushing either pedal will open the switch.

------------------
Rod Schneider, Woodstock, Ga.
"You can't have too many toys!"
1988 Fiero GT
1966 Porsche 911
Van's RV-6 airplane-under construction

In case you're curious, the proper way to adjust the cruise cutout switches is to depress the pedal(s) slightly (maybe an inch or so), and slide the switch down toward the pedal until it bottoms. It's in a ratchet mechanism. Then when the pedal comes back up, it will push the switch into just the right position.

I have a question. If the clutch pedal switch is jumpered out, so that you can start the car without depressing the clucth pedal, will this affect the cruise control operation, will it make it inoperative?

quote Originally posted by avengador1: I have a question. If the clutch pedal switch is jumpered out, so that you can start the car without depressing the clucth pedal, will this affect the cruise control operation, will it make it inoperative?

No. Two seperate switches.

------------------
Rod Schneider, Woodstock, Ga.
"You can't have too many toys!"
1988 Fiero GT
1966 Porsche 911
Van's RV-6 airplane-under construction

Thanks, one less thing to worry about.

I found out my module was bad. I had done the same as you.

quote Originally posted by alex de jorge: I found out my module was bad. I had done the same as you.

Same, I had a bad module - only found it out by swapping a spare I had from another car and poof it worked.

Drivers side under the carpet by the gas pedal, black box thing.