lost blower and Lock-up - coincidence?

Jul 26, 2005
The heater core was leaking in my 87 Turbo T, so I replaced it the other day. After re-assembling everything, I tired to turn the blower on and nothing. I tried replaceing the blower motor and re-doing the ground wire on it and still, didnt work. I put power straight from the battery to the blower motor thinking it may be a voltage issue. Still wouldnt fire up... >.< So, I went and grabbed a new blower motor and swapped them out - same thing. :mad: :mad: ended up driving the car to work today, and noticed that the car doesnt wanna go into lockup at all. Is this a coincidence or is something off/fried somewhere? -Ben
allright, checked fuses for A/C and what-not, and they came back okay (but replaced them anyway, just to be sure) Still no blower. I replaced the dash light fuse while I was down there (been out for awhile but never drive it at night sooo) With the fuse in, the transmission would NOT shift unless I let off the gas at like 5500rpm in every gear. I tried adjusting the detent but it wasnt havin it. Pulled the dash light fuse and it started shifting normally again, but now no longer has 4th. :O Any idea what the frak is happening (besides me feeling like this car is posessed?)
Did you give the fan motor both power and ground?

Perhaps you have a ground that is not connected for the transmission and blower?

I would make sure that TV cable is adjusted properly. I am pretty sure it controls fluid pressure. Transmissions have been torn up because of that cable not being adjusted correctly. Perhaps the cable needs replaced if the adjuster is not functioning correctly?

Best wishes and God bless,
Paul Lohr
Pretty obvious there's wiring shorted together, has open circuit, etc.
Suggest you start with a wiring diagram, and trace the system. [as in finding why the dash fuse blew, to begin with?]
"Throwing" parts at it only lightens the wallet.
Get out the test lite, vom, and get busy.
This is a hotair swap, right?? Could be issues with that.
Sorry, This isnt on the GN, this is on the 87 Turbo T. The fan motors ground wire was all corroded up so I re-ran it and got a better ground on the body. The only thing I can think of was what was the purpose of the ground wire that goes to the firewall from on top of the heater core itself? What does that ground do there? Re-adjusted the TV cable last night to spec and still no 4th/OD :( I just find it wierd that with the insturment cluster 5 amp fuse in the transmission doesnt want to shift, and with it out it shifts normally (but without 4th gear). o_O I always get the wierd issues... >_> -Ben
The ground to the heater core is to prevent electrolysis from eating the core. Has to do with electrical potentials that are created by the coolant and different types of metals in contact with it.

The 5 amp fuse: if this is the one near the top under the CRUISE fuse, labeled INST LPS, it is for the various interior lights that come on with the headlight switch, and get dimmed/brightened via the dash dimmer switch. Such as the cluster illumination, console gear indicator and HVAC control panel.

Any chance the fuse in question is the GAUGES fuse (bottom center)? That should be a 20 amp fuse and will affect TCC lockup. It provides power to the TCC solenoid, and also to the VSS and CEL light.

Note that the only thing in the 200-4R transmission that is electrically controlled is the TCC lockup. All shifting is done hydro-mechanically. And is extremely reliant on the TC cable being properly adjusted. It may be going into 4th, but without the lockup active, may not be able to tell what is going on.

The TV valve in the transmission may also get sticky, which will cause high shifts and such.

Yes, the 5amp under the CRUISE fuse. With the 5amp fuse installed, it causes crazy/high RPM shifts that are super hard. Without fuse, it shifts/drives normally. I have not checked the GAUGES fuse, but with that out wouldnt the CEL and speedo not operate? This could all be coincidence and the trans really has lost 4th, but the trans was put together earlier this year so its hard to say... -Ben
It has to be coincidence between the INST LPS fuse and the transmission shifting funny. There really isn't any physical or electrical connection between them.

The only item could be that someone used the power from that fuse for the TCC solenoid power. Such as doing a re-wire on it. Hopefully not. But that would only affect TCC lockup, not shift points.

GAUGES fuse: will lose the CEL light, but not the speedometer, that is cable driven. With the VSS for the ECM being picked up off the back of the speedometer head. The VSS buffer is powered by the GAUGES fuse.

The wiring is VERY goofy on this car. I've had to re-wire the pillar gauges, the radio wires, and headlight wires thus far just to make those things work. I cant explain the INST LPS any other way: with fuse in, shifts high rpm and hard, fuse out it shifts soft and normal. Its the most bizzare thing, but like you said, who knows what kinda funhouse wiring they've got goin on under there....and electrical work is NOT my forte'... >_>
Fuse in, hard shift due to wiring issue, [short to other wire, hooked up wrong, etc], causing the LU to stay engaged??
Thats what Im wondering. Maybe the PO had a problem with the LU on whatever circuit it was on originally and re-wired it to the light switch. So now, fuse in it locks it in all gears and thats causeing the hard/hi shifts and fuse out it locks normally? The 4th gear issue has to be an internal problem Im guessing, as the cable is adjusted correctly now.
Time to do some continuity checks on the wires to the LU solenoid and the fuse panel. A VOM w/ an audio signal should tell you what you need.
Get out the schematics and find the wires...
The lockup doesnt have anything to do with the 4th gear not engageing does it? I thought it was all vac/hydro based - maybe valve body gummed up/missadjusted? -Ben
It's ground based on the valve body. There are two pressure switches with ground wires hooked to them. I think I'm right on that. Been a while.
It's ground based on the valve body. There are two pressure switches with ground wires hooked to them. I think I'm right on that. Been a while.
I'll pull the valve body out of it soon as I get my truck running right enough to DD again and check it all over.
Update - Id read something about takeing the car up to 55mph and letting off the throttle to see if it will shift. It shifted to 4th, but the second I got back on the throttle it downshifted back to 3rd again. Something miss adjusted here? :confused: